OpenCloudOS-Kernel/net/core/pktgen.c

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/*
* Authors:
* Copyright 2001, 2002 by Robert Olsson <robert.olsson@its.uu.se>
* Uppsala University and
* Swedish University of Agricultural Sciences
*
* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
* Ben Greear <greearb@candelatech.com>
* Jens Låås <jens.laas@data.slu.se>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*
* A tool for loading the network with preconfigurated packets.
* The tool is implemented as a linux module. Parameters are output
* device, delay (to hard_xmit), number of packets, and whether
* to use multiple SKBs or just the same one.
* pktgen uses the installed interface's output routine.
*
* Additional hacking by:
*
* Jens.Laas@data.slu.se
* Improved by ANK. 010120.
* Improved by ANK even more. 010212.
* MAC address typo fixed. 010417 --ro
* Integrated. 020301 --DaveM
* Added multiskb option 020301 --DaveM
* Scaling of results. 020417--sigurdur@linpro.no
* Significant re-work of the module:
* * Convert to threaded model to more efficiently be able to transmit
* and receive on multiple interfaces at once.
* * Converted many counters to __u64 to allow longer runs.
* * Allow configuration of ranges, like min/max IP address, MACs,
* and UDP-ports, for both source and destination, and can
* set to use a random distribution or sequentially walk the range.
* * Can now change most values after starting.
* * Place 12-byte packet in UDP payload with magic number,
* sequence number, and timestamp.
* * Add receiver code that detects dropped pkts, re-ordered pkts, and
* latencies (with micro-second) precision.
* * Add IOCTL interface to easily get counters & configuration.
* --Ben Greear <greearb@candelatech.com>
*
* Renamed multiskb to clone_skb and cleaned up sending core for two distinct
* skb modes. A clone_skb=0 mode for Ben "ranges" work and a clone_skb != 0
* as a "fastpath" with a configurable number of clones after alloc's.
* clone_skb=0 means all packets are allocated this also means ranges time
* stamps etc can be used. clone_skb=100 means 1 malloc is followed by 100
* clones.
*
* Also moved to /proc/net/pktgen/
* --ro
*
* Sept 10: Fixed threading/locking. Lots of bone-headed and more clever
* mistakes. Also merged in DaveM's patch in the -pre6 patch.
* --Ben Greear <greearb@candelatech.com>
*
* Integrated to 2.5.x 021029 --Lucio Maciel (luciomaciel@zipmail.com.br)
*
*
* 021124 Finished major redesign and rewrite for new functionality.
* See Documentation/networking/pktgen.txt for how to use this.
*
* The new operation:
* For each CPU one thread/process is created at start. This process checks
* for running devices in the if_list and sends packets until count is 0 it
* also the thread checks the thread->control which is used for inter-process
* communication. controlling process "posts" operations to the threads this
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
* way.
* The if_list is RCU protected, and the if_lock remains to protect updating
* of if_list, from "add_device" as it invoked from userspace (via proc write).
*
* By design there should only be *one* "controlling" process. In practice
* multiple write accesses gives unpredictable result. Understood by "write"
* to /proc gives result code thats should be read be the "writer".
* For practical use this should be no problem.
*
* Note when adding devices to a specific CPU there good idea to also assign
* /proc/irq/XX/smp_affinity so TX-interrupts gets bound to the same CPU.
* --ro
*
* Fix refcount off by one if first packet fails, potential null deref,
* memleak 030710- KJP
*
* First "ranges" functionality for ipv6 030726 --ro
*
* Included flow support. 030802 ANK.
*
* Fixed unaligned access on IA-64 Grant Grundler <grundler@parisc-linux.org>
*
* Remove if fix from added Harald Welte <laforge@netfilter.org> 040419
* ia64 compilation fix from Aron Griffis <aron@hp.com> 040604
*
* New xmit() return, do_div and misc clean up by Stephen Hemminger
* <shemminger@osdl.org> 040923
*
* Randy Dunlap fixed u64 printk compiler waring
*
* Remove FCS from BW calculation. Lennert Buytenhek <buytenh@wantstofly.org>
* New time handling. Lennert Buytenhek <buytenh@wantstofly.org> 041213
*
* Corrections from Nikolai Malykh (nmalykh@bilim.com)
* Removed unused flags F_SET_SRCMAC & F_SET_SRCIP 041230
*
* interruptible_sleep_on_timeout() replaced Nishanth Aravamudan <nacc@us.ibm.com>
* 050103
*
* MPLS support by Steven Whitehouse <steve@chygwyn.com>
*
* 802.1Q/Q-in-Q support by Francesco Fondelli (FF) <francesco.fondelli@gmail.com>
*
* Fixed src_mac command to set source mac of packet to value specified in
* command by Adit Ranadive <adit.262@gmail.com>
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/sys.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/unistd.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/capability.h>
#include <linux/hrtimer.h>
#include <linux/freezer.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/inet.h>
#include <linux/inetdevice.h>
#include <linux/rtnetlink.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/udp.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/wait.h>
#include <linux/etherdevice.h>
#include <linux/kthread.h>
#include <linux/prefetch.h>
#include <net/net_namespace.h>
#include <net/checksum.h>
#include <net/ipv6.h>
#include <net/udp.h>
#include <net/ip6_checksum.h>
#include <net/addrconf.h>
#ifdef CONFIG_XFRM
#include <net/xfrm.h>
#endif
#include <net/netns/generic.h>
#include <asm/byteorder.h>
#include <linux/rcupdate.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/timex.h>
#include <linux/uaccess.h>
#include <asm/dma.h>
#include <asm/div64.h> /* do_div */
#define VERSION "2.74"
#define IP_NAME_SZ 32
#define MAX_MPLS_LABELS 16 /* This is the max label stack depth */
#define MPLS_STACK_BOTTOM htonl(0x00000100)
#define func_enter() pr_debug("entering %s\n", __func__);
/* Device flag bits */
#define F_IPSRC_RND (1<<0) /* IP-Src Random */
#define F_IPDST_RND (1<<1) /* IP-Dst Random */
#define F_UDPSRC_RND (1<<2) /* UDP-Src Random */
#define F_UDPDST_RND (1<<3) /* UDP-Dst Random */
#define F_MACSRC_RND (1<<4) /* MAC-Src Random */
#define F_MACDST_RND (1<<5) /* MAC-Dst Random */
#define F_TXSIZE_RND (1<<6) /* Transmit size is random */
#define F_IPV6 (1<<7) /* Interface in IPV6 Mode */
#define F_MPLS_RND (1<<8) /* Random MPLS labels */
#define F_VID_RND (1<<9) /* Random VLAN ID */
#define F_SVID_RND (1<<10) /* Random SVLAN ID */
#define F_FLOW_SEQ (1<<11) /* Sequential flows */
#define F_IPSEC_ON (1<<12) /* ipsec on for flows */
#define F_QUEUE_MAP_RND (1<<13) /* queue map Random */
#define F_QUEUE_MAP_CPU (1<<14) /* queue map mirrors smp_processor_id() */
#define F_NODE (1<<15) /* Node memory alloc*/
#define F_UDPCSUM (1<<16) /* Include UDP checksum */
/* Thread control flag bits */
#define T_STOP (1<<0) /* Stop run */
#define T_RUN (1<<1) /* Start run */
#define T_REMDEVALL (1<<2) /* Remove all devs */
#define T_REMDEV (1<<3) /* Remove one dev */
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
/* If lock -- protects updating of if_list */
#define if_lock(t) spin_lock(&(t->if_lock));
#define if_unlock(t) spin_unlock(&(t->if_lock));
/* Used to help with determining the pkts on receive */
#define PKTGEN_MAGIC 0xbe9be955
#define PG_PROC_DIR "pktgen"
#define PGCTRL "pgctrl"
#define MAX_CFLOWS 65536
#define VLAN_TAG_SIZE(x) ((x)->vlan_id == 0xffff ? 0 : 4)
#define SVLAN_TAG_SIZE(x) ((x)->svlan_id == 0xffff ? 0 : 4)
struct flow_state {
__be32 cur_daddr;
int count;
#ifdef CONFIG_XFRM
struct xfrm_state *x;
#endif
__u32 flags;
};
/* flow flag bits */
#define F_INIT (1<<0) /* flow has been initialized */
struct pktgen_dev {
/*
* Try to keep frequent/infrequent used vars. separated.
*/
struct proc_dir_entry *entry; /* proc file */
struct pktgen_thread *pg_thread;/* the owner */
struct list_head list; /* chaining in the thread's run-queue */
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
struct rcu_head rcu; /* freed by RCU */
int running; /* if false, the test will stop */
/* If min != max, then we will either do a linear iteration, or
* we will do a random selection from within the range.
*/
__u32 flags;
int removal_mark; /* non-zero => the device is marked for
* removal by worker thread */
int min_pkt_size;
int max_pkt_size;
int pkt_overhead; /* overhead for MPLS, VLANs, IPSEC etc */
int nfrags;
struct page *page;
u64 delay; /* nano-seconds */
__u64 count; /* Default No packets to send */
__u64 sofar; /* How many pkts we've sent so far */
__u64 tx_bytes; /* How many bytes we've transmitted */
__u64 errors; /* Errors when trying to transmit, */
/* runtime counters relating to clone_skb */
__u64 allocated_skbs;
__u32 clone_count;
int last_ok; /* Was last skb sent?
* Or a failed transmit of some sort?
* This will keep sequence numbers in order
*/
ktime_t next_tx;
ktime_t started_at;
ktime_t stopped_at;
u64 idle_acc; /* nano-seconds */
__u32 seq_num;
int clone_skb; /*
* Use multiple SKBs during packet gen.
* If this number is greater than 1, then
* that many copies of the same packet will be
* sent before a new packet is allocated.
* If you want to send 1024 identical packets
* before creating a new packet,
* set clone_skb to 1024.
*/
char dst_min[IP_NAME_SZ]; /* IP, ie 1.2.3.4 */
char dst_max[IP_NAME_SZ]; /* IP, ie 1.2.3.4 */
char src_min[IP_NAME_SZ]; /* IP, ie 1.2.3.4 */
char src_max[IP_NAME_SZ]; /* IP, ie 1.2.3.4 */
struct in6_addr in6_saddr;
struct in6_addr in6_daddr;
struct in6_addr cur_in6_daddr;
struct in6_addr cur_in6_saddr;
/* For ranges */
struct in6_addr min_in6_daddr;
struct in6_addr max_in6_daddr;
struct in6_addr min_in6_saddr;
struct in6_addr max_in6_saddr;
/* If we're doing ranges, random or incremental, then this
* defines the min/max for those ranges.
*/
__be32 saddr_min; /* inclusive, source IP address */
__be32 saddr_max; /* exclusive, source IP address */
__be32 daddr_min; /* inclusive, dest IP address */
__be32 daddr_max; /* exclusive, dest IP address */
__u16 udp_src_min; /* inclusive, source UDP port */
__u16 udp_src_max; /* exclusive, source UDP port */
__u16 udp_dst_min; /* inclusive, dest UDP port */
__u16 udp_dst_max; /* exclusive, dest UDP port */
/* DSCP + ECN */
__u8 tos; /* six MSB of (former) IPv4 TOS
are for dscp codepoint */
__u8 traffic_class; /* ditto for the (former) Traffic Class in IPv6
(see RFC 3260, sec. 4) */
/* MPLS */
unsigned int nr_labels; /* Depth of stack, 0 = no MPLS */
__be32 labels[MAX_MPLS_LABELS];
/* VLAN/SVLAN (802.1Q/Q-in-Q) */
__u8 vlan_p;
__u8 vlan_cfi;
__u16 vlan_id; /* 0xffff means no vlan tag */
__u8 svlan_p;
__u8 svlan_cfi;
__u16 svlan_id; /* 0xffff means no svlan tag */
__u32 src_mac_count; /* How many MACs to iterate through */
__u32 dst_mac_count; /* How many MACs to iterate through */
unsigned char dst_mac[ETH_ALEN];
unsigned char src_mac[ETH_ALEN];
__u32 cur_dst_mac_offset;
__u32 cur_src_mac_offset;
__be32 cur_saddr;
__be32 cur_daddr;
__u16 ip_id;
__u16 cur_udp_dst;
__u16 cur_udp_src;
__u16 cur_queue_map;
__u32 cur_pkt_size;
__u32 last_pkt_size;
__u8 hh[14];
/* = {
0x00, 0x80, 0xC8, 0x79, 0xB3, 0xCB,
We fill in SRC address later
0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x08, 0x00
};
*/
__u16 pad; /* pad out the hh struct to an even 16 bytes */
struct sk_buff *skb; /* skb we are to transmit next, used for when we
* are transmitting the same one multiple times
*/
struct net_device *odev; /* The out-going device.
* Note that the device should have it's
* pg_info pointer pointing back to this
* device.
* Set when the user specifies the out-going
* device name (not when the inject is
* started as it used to do.)
*/
pktgen: Fix device name compares Commit e6fce5b916cd7f7f7 (pktgen: multiqueue etc.) tried to relax the pktgen restriction of one device per kernel thread, adding a '@' tag to device names. Problem is we dont perform check on full pktgen device name. This allows adding many time same 'device' to pktgen thread pgset "add_device eth0@0" one session later : pgset "add_device eth0@0" (This doesnt find previous device) This consumes ~1.5 MBytes of vmalloc memory per round and also triggers this warning : [ 673.186380] proc_dir_entry 'pktgen/eth0@0' already registered [ 673.186383] Modules linked in: pktgen ixgbe ehci_hcd psmouse mdio mousedev evdev [last unloaded: pktgen] [ 673.186406] Pid: 6219, comm: bash Tainted: G W 2.6.32-rc7-03302-g41cec6f-dirty #16 [ 673.186410] Call Trace: [ 673.186417] [<ffffffff8104a29b>] warn_slowpath_common+0x7b/0xc0 [ 673.186422] [<ffffffff8104a341>] warn_slowpath_fmt+0x41/0x50 [ 673.186426] [<ffffffff8114e789>] proc_register+0x109/0x210 [ 673.186433] [<ffffffff8100bf2e>] ? apic_timer_interrupt+0xe/0x20 [ 673.186438] [<ffffffff8114e905>] proc_create_data+0x75/0xd0 [ 673.186444] [<ffffffffa006ad38>] pktgen_thread_write+0x568/0x640 [pktgen] [ 673.186449] [<ffffffffa006a7d0>] ? pktgen_thread_write+0x0/0x640 [pktgen] [ 673.186453] [<ffffffff81149144>] proc_reg_write+0x84/0xc0 [ 673.186458] [<ffffffff810f5a58>] vfs_write+0xb8/0x180 [ 673.186463] [<ffffffff810f5c11>] sys_write+0x51/0x90 [ 673.186468] [<ffffffff8100b51b>] system_call_fastpath+0x16/0x1b [ 673.186470] ---[ end trace ccbb991b0a8d994d ]--- Solution to this problem is to use a odevname field (includes @ tag and suffix), instead of using netdevice name. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Robert Olsson <robert.olsson@its.uu.se> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-23 09:44:37 +08:00
char odevname[32];
struct flow_state *flows;
unsigned int cflows; /* Concurrent flows (config) */
unsigned int lflow; /* Flow length (config) */
unsigned int nflows; /* accumulated flows (stats) */
unsigned int curfl; /* current sequenced flow (state)*/
u16 queue_map_min;
u16 queue_map_max;
__u32 skb_priority; /* skb priority field */
int node; /* Memory node */
#ifdef CONFIG_XFRM
__u8 ipsmode; /* IPSEC mode (config) */
__u8 ipsproto; /* IPSEC type (config) */
__u32 spi;
struct dst_entry dst;
struct dst_ops dstops;
#endif
char result[512];
};
struct pktgen_hdr {
__be32 pgh_magic;
__be32 seq_num;
__be32 tv_sec;
__be32 tv_usec;
};
static int pg_net_id __read_mostly;
struct pktgen_net {
struct net *net;
struct proc_dir_entry *proc_dir;
struct list_head pktgen_threads;
bool pktgen_exiting;
};
struct pktgen_thread {
spinlock_t if_lock; /* for list of devices */
struct list_head if_list; /* All device here */
struct list_head th_list;
struct task_struct *tsk;
char result[512];
/* Field for thread to receive "posted" events terminate,
stop ifs etc. */
u32 control;
int cpu;
wait_queue_head_t queue;
struct completion start_done;
struct pktgen_net *net;
};
#define REMOVE 1
#define FIND 0
static const char version[] =
"Packet Generator for packet performance testing. "
"Version: " VERSION "\n";
static int pktgen_remove_device(struct pktgen_thread *t, struct pktgen_dev *i);
static int pktgen_add_device(struct pktgen_thread *t, const char *ifname);
static struct pktgen_dev *pktgen_find_dev(struct pktgen_thread *t,
const char *ifname, bool exact);
static int pktgen_device_event(struct notifier_block *, unsigned long, void *);
static void pktgen_run_all_threads(struct pktgen_net *pn);
static void pktgen_reset_all_threads(struct pktgen_net *pn);
static void pktgen_stop_all_threads_ifs(struct pktgen_net *pn);
static void pktgen_stop(struct pktgen_thread *t);
static void pktgen_clear_counters(struct pktgen_dev *pkt_dev);
/* Module parameters, defaults. */
static int pg_count_d __read_mostly = 1000;
static int pg_delay_d __read_mostly;
static int pg_clone_skb_d __read_mostly;
static int debug __read_mostly;
static DEFINE_MUTEX(pktgen_thread_lock);
static struct notifier_block pktgen_notifier_block = {
.notifier_call = pktgen_device_event,
};
/*
* /proc handling functions
*
*/
static int pgctrl_show(struct seq_file *seq, void *v)
{
seq_puts(seq, version);
return 0;
}
static ssize_t pgctrl_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
char data[128];
struct pktgen_net *pn = net_generic(current->nsproxy->net_ns, pg_net_id);
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (count == 0)
return -EINVAL;
if (count > sizeof(data))
count = sizeof(data);
if (copy_from_user(data, buf, count))
return -EFAULT;
data[count - 1] = 0; /* Strip trailing '\n' and terminate string */
if (!strcmp(data, "stop"))
pktgen_stop_all_threads_ifs(pn);
else if (!strcmp(data, "start"))
pktgen_run_all_threads(pn);
else if (!strcmp(data, "reset"))
pktgen_reset_all_threads(pn);
else
pr_warning("Unknown command: %s\n", data);
return count;
}
static int pgctrl_open(struct inode *inode, struct file *file)
{
return single_open(file, pgctrl_show, PDE_DATA(inode));
}
static const struct file_operations pktgen_fops = {
.owner = THIS_MODULE,
.open = pgctrl_open,
.read = seq_read,
.llseek = seq_lseek,
.write = pgctrl_write,
.release = single_release,
};
static int pktgen_if_show(struct seq_file *seq, void *v)
{
const struct pktgen_dev *pkt_dev = seq->private;
ktime_t stopped;
u64 idle;
seq_printf(seq,
"Params: count %llu min_pkt_size: %u max_pkt_size: %u\n",
(unsigned long long)pkt_dev->count, pkt_dev->min_pkt_size,
pkt_dev->max_pkt_size);
seq_printf(seq,
" frags: %d delay: %llu clone_skb: %d ifname: %s\n",
pkt_dev->nfrags, (unsigned long long) pkt_dev->delay,
pktgen: Fix device name compares Commit e6fce5b916cd7f7f7 (pktgen: multiqueue etc.) tried to relax the pktgen restriction of one device per kernel thread, adding a '@' tag to device names. Problem is we dont perform check on full pktgen device name. This allows adding many time same 'device' to pktgen thread pgset "add_device eth0@0" one session later : pgset "add_device eth0@0" (This doesnt find previous device) This consumes ~1.5 MBytes of vmalloc memory per round and also triggers this warning : [ 673.186380] proc_dir_entry 'pktgen/eth0@0' already registered [ 673.186383] Modules linked in: pktgen ixgbe ehci_hcd psmouse mdio mousedev evdev [last unloaded: pktgen] [ 673.186406] Pid: 6219, comm: bash Tainted: G W 2.6.32-rc7-03302-g41cec6f-dirty #16 [ 673.186410] Call Trace: [ 673.186417] [<ffffffff8104a29b>] warn_slowpath_common+0x7b/0xc0 [ 673.186422] [<ffffffff8104a341>] warn_slowpath_fmt+0x41/0x50 [ 673.186426] [<ffffffff8114e789>] proc_register+0x109/0x210 [ 673.186433] [<ffffffff8100bf2e>] ? apic_timer_interrupt+0xe/0x20 [ 673.186438] [<ffffffff8114e905>] proc_create_data+0x75/0xd0 [ 673.186444] [<ffffffffa006ad38>] pktgen_thread_write+0x568/0x640 [pktgen] [ 673.186449] [<ffffffffa006a7d0>] ? pktgen_thread_write+0x0/0x640 [pktgen] [ 673.186453] [<ffffffff81149144>] proc_reg_write+0x84/0xc0 [ 673.186458] [<ffffffff810f5a58>] vfs_write+0xb8/0x180 [ 673.186463] [<ffffffff810f5c11>] sys_write+0x51/0x90 [ 673.186468] [<ffffffff8100b51b>] system_call_fastpath+0x16/0x1b [ 673.186470] ---[ end trace ccbb991b0a8d994d ]--- Solution to this problem is to use a odevname field (includes @ tag and suffix), instead of using netdevice name. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Robert Olsson <robert.olsson@its.uu.se> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-23 09:44:37 +08:00
pkt_dev->clone_skb, pkt_dev->odevname);
seq_printf(seq, " flows: %u flowlen: %u\n", pkt_dev->cflows,
pkt_dev->lflow);
seq_printf(seq,
" queue_map_min: %u queue_map_max: %u\n",
pkt_dev->queue_map_min,
pkt_dev->queue_map_max);
if (pkt_dev->skb_priority)
seq_printf(seq, " skb_priority: %u\n",
pkt_dev->skb_priority);
if (pkt_dev->flags & F_IPV6) {
seq_printf(seq,
" saddr: %pI6c min_saddr: %pI6c max_saddr: %pI6c\n"
" daddr: %pI6c min_daddr: %pI6c max_daddr: %pI6c\n",
&pkt_dev->in6_saddr,
&pkt_dev->min_in6_saddr, &pkt_dev->max_in6_saddr,
&pkt_dev->in6_daddr,
&pkt_dev->min_in6_daddr, &pkt_dev->max_in6_daddr);
} else {
seq_printf(seq,
" dst_min: %s dst_max: %s\n",
pkt_dev->dst_min, pkt_dev->dst_max);
seq_printf(seq,
" src_min: %s src_max: %s\n",
pkt_dev->src_min, pkt_dev->src_max);
}
seq_puts(seq, " src_mac: ");
seq_printf(seq, "%pM ",
is_zero_ether_addr(pkt_dev->src_mac) ?
pkt_dev->odev->dev_addr : pkt_dev->src_mac);
seq_puts(seq, "dst_mac: ");
seq_printf(seq, "%pM\n", pkt_dev->dst_mac);
seq_printf(seq,
" udp_src_min: %d udp_src_max: %d"
" udp_dst_min: %d udp_dst_max: %d\n",
pkt_dev->udp_src_min, pkt_dev->udp_src_max,
pkt_dev->udp_dst_min, pkt_dev->udp_dst_max);
seq_printf(seq,
" src_mac_count: %d dst_mac_count: %d\n",
pkt_dev->src_mac_count, pkt_dev->dst_mac_count);
if (pkt_dev->nr_labels) {
unsigned int i;
seq_puts(seq, " mpls: ");
for (i = 0; i < pkt_dev->nr_labels; i++)
seq_printf(seq, "%08x%s", ntohl(pkt_dev->labels[i]),
i == pkt_dev->nr_labels-1 ? "\n" : ", ");
}
if (pkt_dev->vlan_id != 0xffff)
seq_printf(seq, " vlan_id: %u vlan_p: %u vlan_cfi: %u\n",
pkt_dev->vlan_id, pkt_dev->vlan_p,
pkt_dev->vlan_cfi);
if (pkt_dev->svlan_id != 0xffff)
seq_printf(seq, " svlan_id: %u vlan_p: %u vlan_cfi: %u\n",
pkt_dev->svlan_id, pkt_dev->svlan_p,
pkt_dev->svlan_cfi);
if (pkt_dev->tos)
seq_printf(seq, " tos: 0x%02x\n", pkt_dev->tos);
if (pkt_dev->traffic_class)
seq_printf(seq, " traffic_class: 0x%02x\n", pkt_dev->traffic_class);
if (pkt_dev->node >= 0)
seq_printf(seq, " node: %d\n", pkt_dev->node);
seq_puts(seq, " Flags: ");
if (pkt_dev->flags & F_IPV6)
seq_puts(seq, "IPV6 ");
if (pkt_dev->flags & F_IPSRC_RND)
seq_puts(seq, "IPSRC_RND ");
if (pkt_dev->flags & F_IPDST_RND)
seq_puts(seq, "IPDST_RND ");
if (pkt_dev->flags & F_TXSIZE_RND)
seq_puts(seq, "TXSIZE_RND ");
if (pkt_dev->flags & F_UDPSRC_RND)
seq_puts(seq, "UDPSRC_RND ");
if (pkt_dev->flags & F_UDPDST_RND)
seq_puts(seq, "UDPDST_RND ");
if (pkt_dev->flags & F_UDPCSUM)
seq_puts(seq, "UDPCSUM ");
if (pkt_dev->flags & F_MPLS_RND)
seq_puts(seq, "MPLS_RND ");
if (pkt_dev->flags & F_QUEUE_MAP_RND)
seq_puts(seq, "QUEUE_MAP_RND ");
if (pkt_dev->flags & F_QUEUE_MAP_CPU)
seq_puts(seq, "QUEUE_MAP_CPU ");
if (pkt_dev->cflows) {
if (pkt_dev->flags & F_FLOW_SEQ)
seq_puts(seq, "FLOW_SEQ "); /*in sequence flows*/
else
seq_puts(seq, "FLOW_RND ");
}
#ifdef CONFIG_XFRM
if (pkt_dev->flags & F_IPSEC_ON) {
seq_puts(seq, "IPSEC ");
if (pkt_dev->spi)
seq_printf(seq, "spi:%u", pkt_dev->spi);
}
#endif
if (pkt_dev->flags & F_MACSRC_RND)
seq_puts(seq, "MACSRC_RND ");
if (pkt_dev->flags & F_MACDST_RND)
seq_puts(seq, "MACDST_RND ");
if (pkt_dev->flags & F_VID_RND)
seq_puts(seq, "VID_RND ");
if (pkt_dev->flags & F_SVID_RND)
seq_puts(seq, "SVID_RND ");
if (pkt_dev->flags & F_NODE)
seq_puts(seq, "NODE_ALLOC ");
seq_puts(seq, "\n");
/* not really stopped, more like last-running-at */
stopped = pkt_dev->running ? ktime_get() : pkt_dev->stopped_at;
idle = pkt_dev->idle_acc;
do_div(idle, NSEC_PER_USEC);
seq_printf(seq,
"Current:\n pkts-sofar: %llu errors: %llu\n",
(unsigned long long)pkt_dev->sofar,
(unsigned long long)pkt_dev->errors);
seq_printf(seq,
" started: %lluus stopped: %lluus idle: %lluus\n",
(unsigned long long) ktime_to_us(pkt_dev->started_at),
(unsigned long long) ktime_to_us(stopped),
(unsigned long long) idle);
seq_printf(seq,
" seq_num: %d cur_dst_mac_offset: %d cur_src_mac_offset: %d\n",
pkt_dev->seq_num, pkt_dev->cur_dst_mac_offset,
pkt_dev->cur_src_mac_offset);
if (pkt_dev->flags & F_IPV6) {
seq_printf(seq, " cur_saddr: %pI6c cur_daddr: %pI6c\n",
&pkt_dev->cur_in6_saddr,
&pkt_dev->cur_in6_daddr);
} else
seq_printf(seq, " cur_saddr: %pI4 cur_daddr: %pI4\n",
&pkt_dev->cur_saddr, &pkt_dev->cur_daddr);
seq_printf(seq, " cur_udp_dst: %d cur_udp_src: %d\n",
pkt_dev->cur_udp_dst, pkt_dev->cur_udp_src);
seq_printf(seq, " cur_queue_map: %u\n", pkt_dev->cur_queue_map);
seq_printf(seq, " flows: %u\n", pkt_dev->nflows);
if (pkt_dev->result[0])
seq_printf(seq, "Result: %s\n", pkt_dev->result);
else
seq_puts(seq, "Result: Idle\n");
return 0;
}
static int hex32_arg(const char __user *user_buffer, unsigned long maxlen,
__u32 *num)
{
int i = 0;
*num = 0;
for (; i < maxlen; i++) {
int value;
char c;
*num <<= 4;
if (get_user(c, &user_buffer[i]))
return -EFAULT;
value = hex_to_bin(c);
if (value >= 0)
*num |= value;
else
break;
}
return i;
}
static int count_trail_chars(const char __user * user_buffer,
unsigned int maxlen)
{
int i;
for (i = 0; i < maxlen; i++) {
char c;
if (get_user(c, &user_buffer[i]))
return -EFAULT;
switch (c) {
case '\"':
case '\n':
case '\r':
case '\t':
case ' ':
case '=':
break;
default:
goto done;
}
}
done:
return i;
}
static long num_arg(const char __user *user_buffer, unsigned long maxlen,
unsigned long *num)
{
int i;
*num = 0;
for (i = 0; i < maxlen; i++) {
char c;
if (get_user(c, &user_buffer[i]))
return -EFAULT;
if ((c >= '0') && (c <= '9')) {
*num *= 10;
*num += c - '0';
} else
break;
}
return i;
}
static int strn_len(const char __user * user_buffer, unsigned int maxlen)
{
int i;
for (i = 0; i < maxlen; i++) {
char c;
if (get_user(c, &user_buffer[i]))
return -EFAULT;
switch (c) {
case '\"':
case '\n':
case '\r':
case '\t':
case ' ':
goto done_str;
default:
break;
}
}
done_str:
return i;
}
static ssize_t get_labels(const char __user *buffer, struct pktgen_dev *pkt_dev)
{
unsigned int n = 0;
char c;
ssize_t i = 0;
int len;
pkt_dev->nr_labels = 0;
do {
__u32 tmp;
len = hex32_arg(&buffer[i], 8, &tmp);
if (len <= 0)
return len;
pkt_dev->labels[n] = htonl(tmp);
if (pkt_dev->labels[n] & MPLS_STACK_BOTTOM)
pkt_dev->flags |= F_MPLS_RND;
i += len;
if (get_user(c, &buffer[i]))
return -EFAULT;
i++;
n++;
if (n >= MAX_MPLS_LABELS)
return -E2BIG;
} while (c == ',');
pkt_dev->nr_labels = n;
return i;
}
static ssize_t pktgen_if_write(struct file *file,
const char __user * user_buffer, size_t count,
loff_t * offset)
{
struct seq_file *seq = file->private_data;
struct pktgen_dev *pkt_dev = seq->private;
int i, max, len;
char name[16], valstr[32];
unsigned long value = 0;
char *pg_result = NULL;
int tmp = 0;
char buf[128];
pg_result = &(pkt_dev->result[0]);
if (count < 1) {
pr_warning("wrong command format\n");
return -EINVAL;
}
max = count;
tmp = count_trail_chars(user_buffer, max);
if (tmp < 0) {
pr_warning("illegal format\n");
return tmp;
}
i = tmp;
/* Read variable name */
len = strn_len(&user_buffer[i], sizeof(name) - 1);
if (len < 0)
return len;
memset(name, 0, sizeof(name));
if (copy_from_user(name, &user_buffer[i], len))
return -EFAULT;
i += len;
max = count - i;
len = count_trail_chars(&user_buffer[i], max);
if (len < 0)
return len;
i += len;
if (debug) {
size_t copy = min_t(size_t, count, 1023);
char tb[copy + 1];
if (copy_from_user(tb, user_buffer, copy))
return -EFAULT;
tb[copy] = 0;
pr_debug("%s,%lu buffer -:%s:-\n",
name, (unsigned long)count, tb);
}
if (!strcmp(name, "min_pkt_size")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (value < 14 + 20 + 8)
value = 14 + 20 + 8;
if (value != pkt_dev->min_pkt_size) {
pkt_dev->min_pkt_size = value;
pkt_dev->cur_pkt_size = value;
}
sprintf(pg_result, "OK: min_pkt_size=%u",
pkt_dev->min_pkt_size);
return count;
}
if (!strcmp(name, "max_pkt_size")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (value < 14 + 20 + 8)
value = 14 + 20 + 8;
if (value != pkt_dev->max_pkt_size) {
pkt_dev->max_pkt_size = value;
pkt_dev->cur_pkt_size = value;
}
sprintf(pg_result, "OK: max_pkt_size=%u",
pkt_dev->max_pkt_size);
return count;
}
/* Shortcut for min = max */
if (!strcmp(name, "pkt_size")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (value < 14 + 20 + 8)
value = 14 + 20 + 8;
if (value != pkt_dev->min_pkt_size) {
pkt_dev->min_pkt_size = value;
pkt_dev->max_pkt_size = value;
pkt_dev->cur_pkt_size = value;
}
sprintf(pg_result, "OK: pkt_size=%u", pkt_dev->min_pkt_size);
return count;
}
if (!strcmp(name, "debug")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
debug = value;
sprintf(pg_result, "OK: debug=%u", debug);
return count;
}
if (!strcmp(name, "frags")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
pkt_dev->nfrags = value;
sprintf(pg_result, "OK: frags=%u", pkt_dev->nfrags);
return count;
}
if (!strcmp(name, "delay")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (value == 0x7FFFFFFF)
pkt_dev->delay = ULLONG_MAX;
else
pkt_dev->delay = (u64)value;
sprintf(pg_result, "OK: delay=%llu",
(unsigned long long) pkt_dev->delay);
return count;
}
if (!strcmp(name, "rate")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (!value)
return len;
pkt_dev->delay = pkt_dev->min_pkt_size*8*NSEC_PER_USEC/value;
if (debug)
pr_info("Delay set at: %llu ns\n", pkt_dev->delay);
sprintf(pg_result, "OK: rate=%lu", value);
return count;
}
if (!strcmp(name, "ratep")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (!value)
return len;
pkt_dev->delay = NSEC_PER_SEC/value;
if (debug)
pr_info("Delay set at: %llu ns\n", pkt_dev->delay);
sprintf(pg_result, "OK: rate=%lu", value);
return count;
}
if (!strcmp(name, "udp_src_min")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (value != pkt_dev->udp_src_min) {
pkt_dev->udp_src_min = value;
pkt_dev->cur_udp_src = value;
}
sprintf(pg_result, "OK: udp_src_min=%u", pkt_dev->udp_src_min);
return count;
}
if (!strcmp(name, "udp_dst_min")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (value != pkt_dev->udp_dst_min) {
pkt_dev->udp_dst_min = value;
pkt_dev->cur_udp_dst = value;
}
sprintf(pg_result, "OK: udp_dst_min=%u", pkt_dev->udp_dst_min);
return count;
}
if (!strcmp(name, "udp_src_max")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (value != pkt_dev->udp_src_max) {
pkt_dev->udp_src_max = value;
pkt_dev->cur_udp_src = value;
}
sprintf(pg_result, "OK: udp_src_max=%u", pkt_dev->udp_src_max);
return count;
}
if (!strcmp(name, "udp_dst_max")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (value != pkt_dev->udp_dst_max) {
pkt_dev->udp_dst_max = value;
pkt_dev->cur_udp_dst = value;
}
sprintf(pg_result, "OK: udp_dst_max=%u", pkt_dev->udp_dst_max);
return count;
}
if (!strcmp(name, "clone_skb")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
if ((value > 0) &&
(!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))
return -ENOTSUPP;
i += len;
pkt_dev->clone_skb = value;
sprintf(pg_result, "OK: clone_skb=%d", pkt_dev->clone_skb);
return count;
}
if (!strcmp(name, "count")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
pkt_dev->count = value;
sprintf(pg_result, "OK: count=%llu",
(unsigned long long)pkt_dev->count);
return count;
}
if (!strcmp(name, "src_mac_count")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (pkt_dev->src_mac_count != value) {
pkt_dev->src_mac_count = value;
pkt_dev->cur_src_mac_offset = 0;
}
sprintf(pg_result, "OK: src_mac_count=%d",
pkt_dev->src_mac_count);
return count;
}
if (!strcmp(name, "dst_mac_count")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (pkt_dev->dst_mac_count != value) {
pkt_dev->dst_mac_count = value;
pkt_dev->cur_dst_mac_offset = 0;
}
sprintf(pg_result, "OK: dst_mac_count=%d",
pkt_dev->dst_mac_count);
return count;
}
if (!strcmp(name, "node")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (node_possible(value)) {
pkt_dev->node = value;
sprintf(pg_result, "OK: node=%d", pkt_dev->node);
if (pkt_dev->page) {
put_page(pkt_dev->page);
pkt_dev->page = NULL;
}
}
else
sprintf(pg_result, "ERROR: node not possible");
return count;
}
if (!strcmp(name, "flag")) {
char f[32];
memset(f, 0, 32);
len = strn_len(&user_buffer[i], sizeof(f) - 1);
if (len < 0)
return len;
if (copy_from_user(f, &user_buffer[i], len))
return -EFAULT;
i += len;
if (strcmp(f, "IPSRC_RND") == 0)
pkt_dev->flags |= F_IPSRC_RND;
else if (strcmp(f, "!IPSRC_RND") == 0)
pkt_dev->flags &= ~F_IPSRC_RND;
else if (strcmp(f, "TXSIZE_RND") == 0)
pkt_dev->flags |= F_TXSIZE_RND;
else if (strcmp(f, "!TXSIZE_RND") == 0)
pkt_dev->flags &= ~F_TXSIZE_RND;
else if (strcmp(f, "IPDST_RND") == 0)
pkt_dev->flags |= F_IPDST_RND;
else if (strcmp(f, "!IPDST_RND") == 0)
pkt_dev->flags &= ~F_IPDST_RND;
else if (strcmp(f, "UDPSRC_RND") == 0)
pkt_dev->flags |= F_UDPSRC_RND;
else if (strcmp(f, "!UDPSRC_RND") == 0)
pkt_dev->flags &= ~F_UDPSRC_RND;
else if (strcmp(f, "UDPDST_RND") == 0)
pkt_dev->flags |= F_UDPDST_RND;
else if (strcmp(f, "!UDPDST_RND") == 0)
pkt_dev->flags &= ~F_UDPDST_RND;
else if (strcmp(f, "MACSRC_RND") == 0)
pkt_dev->flags |= F_MACSRC_RND;
else if (strcmp(f, "!MACSRC_RND") == 0)
pkt_dev->flags &= ~F_MACSRC_RND;
else if (strcmp(f, "MACDST_RND") == 0)
pkt_dev->flags |= F_MACDST_RND;
else if (strcmp(f, "!MACDST_RND") == 0)
pkt_dev->flags &= ~F_MACDST_RND;
else if (strcmp(f, "MPLS_RND") == 0)
pkt_dev->flags |= F_MPLS_RND;
else if (strcmp(f, "!MPLS_RND") == 0)
pkt_dev->flags &= ~F_MPLS_RND;
else if (strcmp(f, "VID_RND") == 0)
pkt_dev->flags |= F_VID_RND;
else if (strcmp(f, "!VID_RND") == 0)
pkt_dev->flags &= ~F_VID_RND;
else if (strcmp(f, "SVID_RND") == 0)
pkt_dev->flags |= F_SVID_RND;
else if (strcmp(f, "!SVID_RND") == 0)
pkt_dev->flags &= ~F_SVID_RND;
else if (strcmp(f, "FLOW_SEQ") == 0)
pkt_dev->flags |= F_FLOW_SEQ;
else if (strcmp(f, "QUEUE_MAP_RND") == 0)
pkt_dev->flags |= F_QUEUE_MAP_RND;
else if (strcmp(f, "!QUEUE_MAP_RND") == 0)
pkt_dev->flags &= ~F_QUEUE_MAP_RND;
else if (strcmp(f, "QUEUE_MAP_CPU") == 0)
pkt_dev->flags |= F_QUEUE_MAP_CPU;
else if (strcmp(f, "!QUEUE_MAP_CPU") == 0)
pkt_dev->flags &= ~F_QUEUE_MAP_CPU;
#ifdef CONFIG_XFRM
else if (strcmp(f, "IPSEC") == 0)
pkt_dev->flags |= F_IPSEC_ON;
#endif
else if (strcmp(f, "!IPV6") == 0)
pkt_dev->flags &= ~F_IPV6;
else if (strcmp(f, "NODE_ALLOC") == 0)
pkt_dev->flags |= F_NODE;
else if (strcmp(f, "!NODE_ALLOC") == 0)
pkt_dev->flags &= ~F_NODE;
else if (strcmp(f, "UDPCSUM") == 0)
pkt_dev->flags |= F_UDPCSUM;
else if (strcmp(f, "!UDPCSUM") == 0)
pkt_dev->flags &= ~F_UDPCSUM;
else {
sprintf(pg_result,
"Flag -:%s:- unknown\nAvailable flags, (prepend ! to un-set flag):\n%s",
f,
"IPSRC_RND, IPDST_RND, UDPSRC_RND, UDPDST_RND, "
"MACSRC_RND, MACDST_RND, TXSIZE_RND, IPV6, "
"MPLS_RND, VID_RND, SVID_RND, FLOW_SEQ, "
"QUEUE_MAP_RND, QUEUE_MAP_CPU, UDPCSUM, "
#ifdef CONFIG_XFRM
"IPSEC, "
#endif
"NODE_ALLOC\n");
return count;
}
sprintf(pg_result, "OK: flags=0x%x", pkt_dev->flags);
return count;
}
if (!strcmp(name, "dst_min") || !strcmp(name, "dst")) {
len = strn_len(&user_buffer[i], sizeof(pkt_dev->dst_min) - 1);
if (len < 0)
return len;
if (copy_from_user(buf, &user_buffer[i], len))
return -EFAULT;
buf[len] = 0;
if (strcmp(buf, pkt_dev->dst_min) != 0) {
memset(pkt_dev->dst_min, 0, sizeof(pkt_dev->dst_min));
strncpy(pkt_dev->dst_min, buf, len);
pkt_dev->daddr_min = in_aton(pkt_dev->dst_min);
pkt_dev->cur_daddr = pkt_dev->daddr_min;
}
if (debug)
pr_debug("dst_min set to: %s\n", pkt_dev->dst_min);
i += len;
sprintf(pg_result, "OK: dst_min=%s", pkt_dev->dst_min);
return count;
}
if (!strcmp(name, "dst_max")) {
len = strn_len(&user_buffer[i], sizeof(pkt_dev->dst_max) - 1);
if (len < 0)
return len;
if (copy_from_user(buf, &user_buffer[i], len))
return -EFAULT;
buf[len] = 0;
if (strcmp(buf, pkt_dev->dst_max) != 0) {
memset(pkt_dev->dst_max, 0, sizeof(pkt_dev->dst_max));
strncpy(pkt_dev->dst_max, buf, len);
pkt_dev->daddr_max = in_aton(pkt_dev->dst_max);
pkt_dev->cur_daddr = pkt_dev->daddr_max;
}
if (debug)
pr_debug("dst_max set to: %s\n", pkt_dev->dst_max);
i += len;
sprintf(pg_result, "OK: dst_max=%s", pkt_dev->dst_max);
return count;
}
if (!strcmp(name, "dst6")) {
len = strn_len(&user_buffer[i], sizeof(buf) - 1);
if (len < 0)
return len;
pkt_dev->flags |= F_IPV6;
if (copy_from_user(buf, &user_buffer[i], len))
return -EFAULT;
buf[len] = 0;
in6_pton(buf, -1, pkt_dev->in6_daddr.s6_addr, -1, NULL);
snprintf(buf, sizeof(buf), "%pI6c", &pkt_dev->in6_daddr);
pkt_dev->cur_in6_daddr = pkt_dev->in6_daddr;
if (debug)
pr_debug("dst6 set to: %s\n", buf);
i += len;
sprintf(pg_result, "OK: dst6=%s", buf);
return count;
}
if (!strcmp(name, "dst6_min")) {
len = strn_len(&user_buffer[i], sizeof(buf) - 1);
if (len < 0)
return len;
pkt_dev->flags |= F_IPV6;
if (copy_from_user(buf, &user_buffer[i], len))
return -EFAULT;
buf[len] = 0;
in6_pton(buf, -1, pkt_dev->min_in6_daddr.s6_addr, -1, NULL);
snprintf(buf, sizeof(buf), "%pI6c", &pkt_dev->min_in6_daddr);
pkt_dev->cur_in6_daddr = pkt_dev->min_in6_daddr;
if (debug)
pr_debug("dst6_min set to: %s\n", buf);
i += len;
sprintf(pg_result, "OK: dst6_min=%s", buf);
return count;
}
if (!strcmp(name, "dst6_max")) {
len = strn_len(&user_buffer[i], sizeof(buf) - 1);
if (len < 0)
return len;
pkt_dev->flags |= F_IPV6;
if (copy_from_user(buf, &user_buffer[i], len))
return -EFAULT;
buf[len] = 0;
in6_pton(buf, -1, pkt_dev->max_in6_daddr.s6_addr, -1, NULL);
snprintf(buf, sizeof(buf), "%pI6c", &pkt_dev->max_in6_daddr);
if (debug)
pr_debug("dst6_max set to: %s\n", buf);
i += len;
sprintf(pg_result, "OK: dst6_max=%s", buf);
return count;
}
if (!strcmp(name, "src6")) {
len = strn_len(&user_buffer[i], sizeof(buf) - 1);
if (len < 0)
return len;
pkt_dev->flags |= F_IPV6;
if (copy_from_user(buf, &user_buffer[i], len))
return -EFAULT;
buf[len] = 0;
in6_pton(buf, -1, pkt_dev->in6_saddr.s6_addr, -1, NULL);
snprintf(buf, sizeof(buf), "%pI6c", &pkt_dev->in6_saddr);
pkt_dev->cur_in6_saddr = pkt_dev->in6_saddr;
if (debug)
pr_debug("src6 set to: %s\n", buf);
i += len;
sprintf(pg_result, "OK: src6=%s", buf);
return count;
}
if (!strcmp(name, "src_min")) {
len = strn_len(&user_buffer[i], sizeof(pkt_dev->src_min) - 1);
if (len < 0)
return len;
if (copy_from_user(buf, &user_buffer[i], len))
return -EFAULT;
buf[len] = 0;
if (strcmp(buf, pkt_dev->src_min) != 0) {
memset(pkt_dev->src_min, 0, sizeof(pkt_dev->src_min));
strncpy(pkt_dev->src_min, buf, len);
pkt_dev->saddr_min = in_aton(pkt_dev->src_min);
pkt_dev->cur_saddr = pkt_dev->saddr_min;
}
if (debug)
pr_debug("src_min set to: %s\n", pkt_dev->src_min);
i += len;
sprintf(pg_result, "OK: src_min=%s", pkt_dev->src_min);
return count;
}
if (!strcmp(name, "src_max")) {
len = strn_len(&user_buffer[i], sizeof(pkt_dev->src_max) - 1);
if (len < 0)
return len;
if (copy_from_user(buf, &user_buffer[i], len))
return -EFAULT;
buf[len] = 0;
if (strcmp(buf, pkt_dev->src_max) != 0) {
memset(pkt_dev->src_max, 0, sizeof(pkt_dev->src_max));
strncpy(pkt_dev->src_max, buf, len);
pkt_dev->saddr_max = in_aton(pkt_dev->src_max);
pkt_dev->cur_saddr = pkt_dev->saddr_max;
}
if (debug)
pr_debug("src_max set to: %s\n", pkt_dev->src_max);
i += len;
sprintf(pg_result, "OK: src_max=%s", pkt_dev->src_max);
return count;
}
if (!strcmp(name, "dst_mac")) {
len = strn_len(&user_buffer[i], sizeof(valstr) - 1);
if (len < 0)
return len;
memset(valstr, 0, sizeof(valstr));
if (copy_from_user(valstr, &user_buffer[i], len))
return -EFAULT;
if (!mac_pton(valstr, pkt_dev->dst_mac))
return -EINVAL;
/* Set up Dest MAC */
ether_addr_copy(&pkt_dev->hh[0], pkt_dev->dst_mac);
sprintf(pg_result, "OK: dstmac %pM", pkt_dev->dst_mac);
return count;
}
if (!strcmp(name, "src_mac")) {
len = strn_len(&user_buffer[i], sizeof(valstr) - 1);
if (len < 0)
return len;
memset(valstr, 0, sizeof(valstr));
if (copy_from_user(valstr, &user_buffer[i], len))
return -EFAULT;
if (!mac_pton(valstr, pkt_dev->src_mac))
return -EINVAL;
/* Set up Src MAC */
ether_addr_copy(&pkt_dev->hh[6], pkt_dev->src_mac);
sprintf(pg_result, "OK: srcmac %pM", pkt_dev->src_mac);
return count;
}
if (!strcmp(name, "clear_counters")) {
pktgen_clear_counters(pkt_dev);
sprintf(pg_result, "OK: Clearing counters.\n");
return count;
}
if (!strcmp(name, "flows")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
if (value > MAX_CFLOWS)
value = MAX_CFLOWS;
pkt_dev->cflows = value;
sprintf(pg_result, "OK: flows=%u", pkt_dev->cflows);
return count;
}
#ifdef CONFIG_XFRM
if (!strcmp(name, "spi")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
pkt_dev->spi = value;
sprintf(pg_result, "OK: spi=%u", pkt_dev->spi);
return count;
}
#endif
if (!strcmp(name, "flowlen")) {
len = num_arg(&user_buffer[i], 10, &value);
if (len < 0)
return len;
i += len;
pkt_dev->lflow = value;
sprintf(pg_result, "OK: flowlen=%u", pkt_dev->lflow);
return count;
}
if (!strcmp(name, "queue_map_min")) {
len = num_arg(&user_buffer[i], 5, &value);
if (len < 0)
return len;
i += len;
pkt_dev->queue_map_min = value;
sprintf(pg_result, "OK: queue_map_min=%u", pkt_dev->queue_map_min);
return count;
}
if (!strcmp(name, "queue_map_max")) {
len = num_arg(&user_buffer[i], 5, &value);
if (len < 0)
return len;
i += len;
pkt_dev->queue_map_max = value;
sprintf(pg_result, "OK: queue_map_max=%u", pkt_dev->queue_map_max);
return count;
}
if (!strcmp(name, "mpls")) {
unsigned int n, cnt;
len = get_labels(&user_buffer[i], pkt_dev);
if (len < 0)
return len;
i += len;
cnt = sprintf(pg_result, "OK: mpls=");
for (n = 0; n < pkt_dev->nr_labels; n++)
cnt += sprintf(pg_result + cnt,
"%08x%s", ntohl(pkt_dev->labels[n]),
n == pkt_dev->nr_labels-1 ? "" : ",");
if (pkt_dev->nr_labels && pkt_dev->vlan_id != 0xffff) {
pkt_dev->vlan_id = 0xffff; /* turn off VLAN/SVLAN */
pkt_dev->svlan_id = 0xffff;
if (debug)
pr_debug("VLAN/SVLAN auto turned off\n");
}
return count;
}
if (!strcmp(name, "vlan_id")) {
len = num_arg(&user_buffer[i], 4, &value);
if (len < 0)
return len;
i += len;
if (value <= 4095) {
pkt_dev->vlan_id = value; /* turn on VLAN */
if (debug)
pr_debug("VLAN turned on\n");
if (debug && pkt_dev->nr_labels)
pr_debug("MPLS auto turned off\n");
pkt_dev->nr_labels = 0; /* turn off MPLS */
sprintf(pg_result, "OK: vlan_id=%u", pkt_dev->vlan_id);
} else {
pkt_dev->vlan_id = 0xffff; /* turn off VLAN/SVLAN */
pkt_dev->svlan_id = 0xffff;
if (debug)
pr_debug("VLAN/SVLAN turned off\n");
}
return count;
}
if (!strcmp(name, "vlan_p")) {
len = num_arg(&user_buffer[i], 1, &value);
if (len < 0)
return len;
i += len;
if ((value <= 7) && (pkt_dev->vlan_id != 0xffff)) {
pkt_dev->vlan_p = value;
sprintf(pg_result, "OK: vlan_p=%u", pkt_dev->vlan_p);
} else {
sprintf(pg_result, "ERROR: vlan_p must be 0-7");
}
return count;
}
if (!strcmp(name, "vlan_cfi")) {
len = num_arg(&user_buffer[i], 1, &value);
if (len < 0)
return len;
i += len;
if ((value <= 1) && (pkt_dev->vlan_id != 0xffff)) {
pkt_dev->vlan_cfi = value;
sprintf(pg_result, "OK: vlan_cfi=%u", pkt_dev->vlan_cfi);
} else {
sprintf(pg_result, "ERROR: vlan_cfi must be 0-1");
}
return count;
}
if (!strcmp(name, "svlan_id")) {
len = num_arg(&user_buffer[i], 4, &value);
if (len < 0)
return len;
i += len;
if ((value <= 4095) && ((pkt_dev->vlan_id != 0xffff))) {
pkt_dev->svlan_id = value; /* turn on SVLAN */
if (debug)
pr_debug("SVLAN turned on\n");
if (debug && pkt_dev->nr_labels)
pr_debug("MPLS auto turned off\n");
pkt_dev->nr_labels = 0; /* turn off MPLS */
sprintf(pg_result, "OK: svlan_id=%u", pkt_dev->svlan_id);
} else {
pkt_dev->vlan_id = 0xffff; /* turn off VLAN/SVLAN */
pkt_dev->svlan_id = 0xffff;
if (debug)
pr_debug("VLAN/SVLAN turned off\n");
}
return count;
}
if (!strcmp(name, "svlan_p")) {
len = num_arg(&user_buffer[i], 1, &value);
if (len < 0)
return len;
i += len;
if ((value <= 7) && (pkt_dev->svlan_id != 0xffff)) {
pkt_dev->svlan_p = value;
sprintf(pg_result, "OK: svlan_p=%u", pkt_dev->svlan_p);
} else {
sprintf(pg_result, "ERROR: svlan_p must be 0-7");
}
return count;
}
if (!strcmp(name, "svlan_cfi")) {
len = num_arg(&user_buffer[i], 1, &value);
if (len < 0)
return len;
i += len;
if ((value <= 1) && (pkt_dev->svlan_id != 0xffff)) {
pkt_dev->svlan_cfi = value;
sprintf(pg_result, "OK: svlan_cfi=%u", pkt_dev->svlan_cfi);
} else {
sprintf(pg_result, "ERROR: svlan_cfi must be 0-1");
}
return count;
}
if (!strcmp(name, "tos")) {
__u32 tmp_value = 0;
len = hex32_arg(&user_buffer[i], 2, &tmp_value);
if (len < 0)
return len;
i += len;
if (len == 2) {
pkt_dev->tos = tmp_value;
sprintf(pg_result, "OK: tos=0x%02x", pkt_dev->tos);
} else {
sprintf(pg_result, "ERROR: tos must be 00-ff");
}
return count;
}
if (!strcmp(name, "traffic_class")) {
__u32 tmp_value = 0;
len = hex32_arg(&user_buffer[i], 2, &tmp_value);
if (len < 0)
return len;
i += len;
if (len == 2) {
pkt_dev->traffic_class = tmp_value;
sprintf(pg_result, "OK: traffic_class=0x%02x", pkt_dev->traffic_class);
} else {
sprintf(pg_result, "ERROR: traffic_class must be 00-ff");
}
return count;
}
if (!strcmp(name, "skb_priority")) {
len = num_arg(&user_buffer[i], 9, &value);
if (len < 0)
return len;
i += len;
pkt_dev->skb_priority = value;
sprintf(pg_result, "OK: skb_priority=%i",
pkt_dev->skb_priority);
return count;
}
sprintf(pkt_dev->result, "No such parameter \"%s\"", name);
return -EINVAL;
}
static int pktgen_if_open(struct inode *inode, struct file *file)
{
return single_open(file, pktgen_if_show, PDE_DATA(inode));
}
static const struct file_operations pktgen_if_fops = {
.owner = THIS_MODULE,
.open = pktgen_if_open,
.read = seq_read,
.llseek = seq_lseek,
.write = pktgen_if_write,
.release = single_release,
};
static int pktgen_thread_show(struct seq_file *seq, void *v)
{
struct pktgen_thread *t = seq->private;
const struct pktgen_dev *pkt_dev;
BUG_ON(!t);
seq_puts(seq, "Running: ");
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_lock();
list_for_each_entry_rcu(pkt_dev, &t->if_list, list)
if (pkt_dev->running)
pktgen: Fix device name compares Commit e6fce5b916cd7f7f7 (pktgen: multiqueue etc.) tried to relax the pktgen restriction of one device per kernel thread, adding a '@' tag to device names. Problem is we dont perform check on full pktgen device name. This allows adding many time same 'device' to pktgen thread pgset "add_device eth0@0" one session later : pgset "add_device eth0@0" (This doesnt find previous device) This consumes ~1.5 MBytes of vmalloc memory per round and also triggers this warning : [ 673.186380] proc_dir_entry 'pktgen/eth0@0' already registered [ 673.186383] Modules linked in: pktgen ixgbe ehci_hcd psmouse mdio mousedev evdev [last unloaded: pktgen] [ 673.186406] Pid: 6219, comm: bash Tainted: G W 2.6.32-rc7-03302-g41cec6f-dirty #16 [ 673.186410] Call Trace: [ 673.186417] [<ffffffff8104a29b>] warn_slowpath_common+0x7b/0xc0 [ 673.186422] [<ffffffff8104a341>] warn_slowpath_fmt+0x41/0x50 [ 673.186426] [<ffffffff8114e789>] proc_register+0x109/0x210 [ 673.186433] [<ffffffff8100bf2e>] ? apic_timer_interrupt+0xe/0x20 [ 673.186438] [<ffffffff8114e905>] proc_create_data+0x75/0xd0 [ 673.186444] [<ffffffffa006ad38>] pktgen_thread_write+0x568/0x640 [pktgen] [ 673.186449] [<ffffffffa006a7d0>] ? pktgen_thread_write+0x0/0x640 [pktgen] [ 673.186453] [<ffffffff81149144>] proc_reg_write+0x84/0xc0 [ 673.186458] [<ffffffff810f5a58>] vfs_write+0xb8/0x180 [ 673.186463] [<ffffffff810f5c11>] sys_write+0x51/0x90 [ 673.186468] [<ffffffff8100b51b>] system_call_fastpath+0x16/0x1b [ 673.186470] ---[ end trace ccbb991b0a8d994d ]--- Solution to this problem is to use a odevname field (includes @ tag and suffix), instead of using netdevice name. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Robert Olsson <robert.olsson@its.uu.se> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-23 09:44:37 +08:00
seq_printf(seq, "%s ", pkt_dev->odevname);
seq_puts(seq, "\nStopped: ");
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
list_for_each_entry_rcu(pkt_dev, &t->if_list, list)
if (!pkt_dev->running)
pktgen: Fix device name compares Commit e6fce5b916cd7f7f7 (pktgen: multiqueue etc.) tried to relax the pktgen restriction of one device per kernel thread, adding a '@' tag to device names. Problem is we dont perform check on full pktgen device name. This allows adding many time same 'device' to pktgen thread pgset "add_device eth0@0" one session later : pgset "add_device eth0@0" (This doesnt find previous device) This consumes ~1.5 MBytes of vmalloc memory per round and also triggers this warning : [ 673.186380] proc_dir_entry 'pktgen/eth0@0' already registered [ 673.186383] Modules linked in: pktgen ixgbe ehci_hcd psmouse mdio mousedev evdev [last unloaded: pktgen] [ 673.186406] Pid: 6219, comm: bash Tainted: G W 2.6.32-rc7-03302-g41cec6f-dirty #16 [ 673.186410] Call Trace: [ 673.186417] [<ffffffff8104a29b>] warn_slowpath_common+0x7b/0xc0 [ 673.186422] [<ffffffff8104a341>] warn_slowpath_fmt+0x41/0x50 [ 673.186426] [<ffffffff8114e789>] proc_register+0x109/0x210 [ 673.186433] [<ffffffff8100bf2e>] ? apic_timer_interrupt+0xe/0x20 [ 673.186438] [<ffffffff8114e905>] proc_create_data+0x75/0xd0 [ 673.186444] [<ffffffffa006ad38>] pktgen_thread_write+0x568/0x640 [pktgen] [ 673.186449] [<ffffffffa006a7d0>] ? pktgen_thread_write+0x0/0x640 [pktgen] [ 673.186453] [<ffffffff81149144>] proc_reg_write+0x84/0xc0 [ 673.186458] [<ffffffff810f5a58>] vfs_write+0xb8/0x180 [ 673.186463] [<ffffffff810f5c11>] sys_write+0x51/0x90 [ 673.186468] [<ffffffff8100b51b>] system_call_fastpath+0x16/0x1b [ 673.186470] ---[ end trace ccbb991b0a8d994d ]--- Solution to this problem is to use a odevname field (includes @ tag and suffix), instead of using netdevice name. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Robert Olsson <robert.olsson@its.uu.se> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-23 09:44:37 +08:00
seq_printf(seq, "%s ", pkt_dev->odevname);
if (t->result[0])
seq_printf(seq, "\nResult: %s\n", t->result);
else
seq_puts(seq, "\nResult: NA\n");
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_unlock();
return 0;
}
static ssize_t pktgen_thread_write(struct file *file,
const char __user * user_buffer,
size_t count, loff_t * offset)
{
struct seq_file *seq = file->private_data;
struct pktgen_thread *t = seq->private;
int i, max, len, ret;
char name[40];
char *pg_result;
if (count < 1) {
// sprintf(pg_result, "Wrong command format");
return -EINVAL;
}
max = count;
len = count_trail_chars(user_buffer, max);
if (len < 0)
return len;
i = len;
/* Read variable name */
len = strn_len(&user_buffer[i], sizeof(name) - 1);
if (len < 0)
return len;
memset(name, 0, sizeof(name));
if (copy_from_user(name, &user_buffer[i], len))
return -EFAULT;
i += len;
max = count - i;
len = count_trail_chars(&user_buffer[i], max);
if (len < 0)
return len;
i += len;
if (debug)
pr_debug("t=%s, count=%lu\n", name, (unsigned long)count);
if (!t) {
pr_err("ERROR: No thread\n");
ret = -EINVAL;
goto out;
}
pg_result = &(t->result[0]);
if (!strcmp(name, "add_device")) {
char f[32];
memset(f, 0, 32);
len = strn_len(&user_buffer[i], sizeof(f) - 1);
if (len < 0) {
ret = len;
goto out;
}
if (copy_from_user(f, &user_buffer[i], len))
return -EFAULT;
i += len;
mutex_lock(&pktgen_thread_lock);
ret = pktgen_add_device(t, f);
mutex_unlock(&pktgen_thread_lock);
if (!ret) {
ret = count;
sprintf(pg_result, "OK: add_device=%s", f);
} else
sprintf(pg_result, "ERROR: can not add device %s", f);
goto out;
}
if (!strcmp(name, "rem_device_all")) {
mutex_lock(&pktgen_thread_lock);
t->control |= T_REMDEVALL;
mutex_unlock(&pktgen_thread_lock);
schedule_timeout_interruptible(msecs_to_jiffies(125)); /* Propagate thread->control */
ret = count;
sprintf(pg_result, "OK: rem_device_all");
goto out;
}
if (!strcmp(name, "max_before_softirq")) {
sprintf(pg_result, "OK: Note! max_before_softirq is obsoleted -- Do not use");
ret = count;
goto out;
}
ret = -EINVAL;
out:
return ret;
}
static int pktgen_thread_open(struct inode *inode, struct file *file)
{
return single_open(file, pktgen_thread_show, PDE_DATA(inode));
}
static const struct file_operations pktgen_thread_fops = {
.owner = THIS_MODULE,
.open = pktgen_thread_open,
.read = seq_read,
.llseek = seq_lseek,
.write = pktgen_thread_write,
.release = single_release,
};
/* Think find or remove for NN */
static struct pktgen_dev *__pktgen_NN_threads(const struct pktgen_net *pn,
const char *ifname, int remove)
{
struct pktgen_thread *t;
struct pktgen_dev *pkt_dev = NULL;
bool exact = (remove == FIND);
list_for_each_entry(t, &pn->pktgen_threads, th_list) {
pkt_dev = pktgen_find_dev(t, ifname, exact);
if (pkt_dev) {
if (remove) {
pkt_dev->removal_mark = 1;
t->control |= T_REMDEV;
}
break;
}
}
return pkt_dev;
}
/*
* mark a device for removal
*/
static void pktgen_mark_device(const struct pktgen_net *pn, const char *ifname)
{
struct pktgen_dev *pkt_dev = NULL;
const int max_tries = 10, msec_per_try = 125;
int i = 0;
mutex_lock(&pktgen_thread_lock);
pr_debug("%s: marking %s for removal\n", __func__, ifname);
while (1) {
pkt_dev = __pktgen_NN_threads(pn, ifname, REMOVE);
if (pkt_dev == NULL)
break; /* success */
mutex_unlock(&pktgen_thread_lock);
pr_debug("%s: waiting for %s to disappear....\n",
__func__, ifname);
schedule_timeout_interruptible(msecs_to_jiffies(msec_per_try));
mutex_lock(&pktgen_thread_lock);
if (++i >= max_tries) {
pr_err("%s: timed out after waiting %d msec for device %s to be removed\n",
__func__, msec_per_try * i, ifname);
break;
}
}
mutex_unlock(&pktgen_thread_lock);
}
static void pktgen_change_name(const struct pktgen_net *pn, struct net_device *dev)
{
struct pktgen_thread *t;
list_for_each_entry(t, &pn->pktgen_threads, th_list) {
struct pktgen_dev *pkt_dev;
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_lock();
list_for_each_entry_rcu(pkt_dev, &t->if_list, list) {
if (pkt_dev->odev != dev)
continue;
proc_remove(pkt_dev->entry);
pkt_dev->entry = proc_create_data(dev->name, 0600,
pn->proc_dir,
&pktgen_if_fops,
pkt_dev);
if (!pkt_dev->entry)
pr_err("can't move proc entry for '%s'\n",
dev->name);
break;
}
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_unlock();
}
}
static int pktgen_device_event(struct notifier_block *unused,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct pktgen_net *pn = net_generic(dev_net(dev), pg_net_id);
if (pn->pktgen_exiting)
return NOTIFY_DONE;
/* It is OK that we do not hold the group lock right now,
* as we run under the RTNL lock.
*/
switch (event) {
case NETDEV_CHANGENAME:
pktgen_change_name(pn, dev);
break;
case NETDEV_UNREGISTER:
pktgen_mark_device(pn, dev->name);
break;
}
return NOTIFY_DONE;
}
static struct net_device *pktgen_dev_get_by_name(const struct pktgen_net *pn,
struct pktgen_dev *pkt_dev,
const char *ifname)
{
char b[IFNAMSIZ+5];
int i;
for (i = 0; ifname[i] != '@'; i++) {
if (i == IFNAMSIZ)
break;
b[i] = ifname[i];
}
b[i] = 0;
return dev_get_by_name(pn->net, b);
}
/* Associate pktgen_dev with a device. */
static int pktgen_setup_dev(const struct pktgen_net *pn,
struct pktgen_dev *pkt_dev, const char *ifname)
{
struct net_device *odev;
int err;
/* Clean old setups */
if (pkt_dev->odev) {
dev_put(pkt_dev->odev);
pkt_dev->odev = NULL;
}
odev = pktgen_dev_get_by_name(pn, pkt_dev, ifname);
if (!odev) {
pr_err("no such netdevice: \"%s\"\n", ifname);
return -ENODEV;
}
if (odev->type != ARPHRD_ETHER) {
pr_err("not an ethernet device: \"%s\"\n", ifname);
err = -EINVAL;
} else if (!netif_running(odev)) {
pr_err("device is down: \"%s\"\n", ifname);
err = -ENETDOWN;
} else {
pkt_dev->odev = odev;
return 0;
}
dev_put(odev);
return err;
}
/* Read pkt_dev from the interface and set up internal pktgen_dev
* structure to have the right information to create/send packets
*/
static void pktgen_setup_inject(struct pktgen_dev *pkt_dev)
{
int ntxq;
if (!pkt_dev->odev) {
pr_err("ERROR: pkt_dev->odev == NULL in setup_inject\n");
sprintf(pkt_dev->result,
"ERROR: pkt_dev->odev == NULL in setup_inject.\n");
return;
}
/* make sure that we don't pick a non-existing transmit queue */
ntxq = pkt_dev->odev->real_num_tx_queues;
if (ntxq <= pkt_dev->queue_map_min) {
pr_warning("WARNING: Requested queue_map_min (zero-based) (%d) exceeds valid range [0 - %d] for (%d) queues on %s, resetting\n",
pkt_dev->queue_map_min, (ntxq ?: 1) - 1, ntxq,
pkt_dev->odevname);
pkt_dev->queue_map_min = (ntxq ?: 1) - 1;
}
if (pkt_dev->queue_map_max >= ntxq) {
pr_warning("WARNING: Requested queue_map_max (zero-based) (%d) exceeds valid range [0 - %d] for (%d) queues on %s, resetting\n",
pkt_dev->queue_map_max, (ntxq ?: 1) - 1, ntxq,
pkt_dev->odevname);
pkt_dev->queue_map_max = (ntxq ?: 1) - 1;
}
/* Default to the interface's mac if not explicitly set. */
if (is_zero_ether_addr(pkt_dev->src_mac))
ether_addr_copy(&(pkt_dev->hh[6]), pkt_dev->odev->dev_addr);
/* Set up Dest MAC */
ether_addr_copy(&(pkt_dev->hh[0]), pkt_dev->dst_mac);
if (pkt_dev->flags & F_IPV6) {
int i, set = 0, err = 1;
struct inet6_dev *idev;
if (pkt_dev->min_pkt_size == 0) {
pkt_dev->min_pkt_size = 14 + sizeof(struct ipv6hdr)
+ sizeof(struct udphdr)
+ sizeof(struct pktgen_hdr)
+ pkt_dev->pkt_overhead;
}
for (i = 0; i < IN6_ADDR_HSIZE; i++)
if (pkt_dev->cur_in6_saddr.s6_addr[i]) {
set = 1;
break;
}
if (!set) {
/*
* Use linklevel address if unconfigured.
*
* use ipv6_get_lladdr if/when it's get exported
*/
rcu_read_lock();
idev = __in6_dev_get(pkt_dev->odev);
if (idev) {
struct inet6_ifaddr *ifp;
read_lock_bh(&idev->lock);
list_for_each_entry(ifp, &idev->addr_list, if_list) {
if ((ifp->scope & IFA_LINK) &&
!(ifp->flags & IFA_F_TENTATIVE)) {
pkt_dev->cur_in6_saddr = ifp->addr;
err = 0;
break;
}
}
read_unlock_bh(&idev->lock);
}
rcu_read_unlock();
if (err)
pr_err("ERROR: IPv6 link address not available\n");
}
} else {
if (pkt_dev->min_pkt_size == 0) {
pkt_dev->min_pkt_size = 14 + sizeof(struct iphdr)
+ sizeof(struct udphdr)
+ sizeof(struct pktgen_hdr)
+ pkt_dev->pkt_overhead;
}
pkt_dev->saddr_min = 0;
pkt_dev->saddr_max = 0;
if (strlen(pkt_dev->src_min) == 0) {
struct in_device *in_dev;
rcu_read_lock();
in_dev = __in_dev_get_rcu(pkt_dev->odev);
if (in_dev) {
if (in_dev->ifa_list) {
pkt_dev->saddr_min =
in_dev->ifa_list->ifa_address;
pkt_dev->saddr_max = pkt_dev->saddr_min;
}
}
rcu_read_unlock();
} else {
pkt_dev->saddr_min = in_aton(pkt_dev->src_min);
pkt_dev->saddr_max = in_aton(pkt_dev->src_max);
}
pkt_dev->daddr_min = in_aton(pkt_dev->dst_min);
pkt_dev->daddr_max = in_aton(pkt_dev->dst_max);
}
/* Initialize current values. */
pkt_dev->cur_pkt_size = pkt_dev->min_pkt_size;
if (pkt_dev->min_pkt_size > pkt_dev->max_pkt_size)
pkt_dev->max_pkt_size = pkt_dev->min_pkt_size;
pkt_dev->cur_dst_mac_offset = 0;
pkt_dev->cur_src_mac_offset = 0;
pkt_dev->cur_saddr = pkt_dev->saddr_min;
pkt_dev->cur_daddr = pkt_dev->daddr_min;
pkt_dev->cur_udp_dst = pkt_dev->udp_dst_min;
pkt_dev->cur_udp_src = pkt_dev->udp_src_min;
pkt_dev->nflows = 0;
}
static void spin(struct pktgen_dev *pkt_dev, ktime_t spin_until)
{
ktime_t start_time, end_time;
s64 remaining;
struct hrtimer_sleeper t;
hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
hrtimer_set_expires(&t.timer, spin_until);
remaining = ktime_to_ns(hrtimer_expires_remaining(&t.timer));
if (remaining <= 0) {
pkt_dev->next_tx = ktime_add_ns(spin_until, pkt_dev->delay);
return;
}
start_time = ktime_get();
if (remaining < 100000) {
/* for small delays (<100us), just loop until limit is reached */
do {
end_time = ktime_get();
} while (ktime_compare(end_time, spin_until) < 0);
} else {
/* see do_nanosleep */
hrtimer_init_sleeper(&t, current);
do {
set_current_state(TASK_INTERRUPTIBLE);
hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS);
if (!hrtimer_active(&t.timer))
t.task = NULL;
if (likely(t.task))
schedule();
hrtimer_cancel(&t.timer);
} while (t.task && pkt_dev->running && !signal_pending(current));
__set_current_state(TASK_RUNNING);
end_time = ktime_get();
}
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(end_time, start_time));
pkt_dev->next_tx = ktime_add_ns(spin_until, pkt_dev->delay);
}
static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev)
{
pkt_dev->pkt_overhead = 0;
pkt_dev->pkt_overhead += pkt_dev->nr_labels*sizeof(u32);
pkt_dev->pkt_overhead += VLAN_TAG_SIZE(pkt_dev);
pkt_dev->pkt_overhead += SVLAN_TAG_SIZE(pkt_dev);
}
static inline int f_seen(const struct pktgen_dev *pkt_dev, int flow)
{
return !!(pkt_dev->flows[flow].flags & F_INIT);
}
static inline int f_pick(struct pktgen_dev *pkt_dev)
{
int flow = pkt_dev->curfl;
if (pkt_dev->flags & F_FLOW_SEQ) {
if (pkt_dev->flows[flow].count >= pkt_dev->lflow) {
/* reset time */
pkt_dev->flows[flow].count = 0;
pkt_dev->flows[flow].flags = 0;
pkt_dev->curfl += 1;
if (pkt_dev->curfl >= pkt_dev->cflows)
pkt_dev->curfl = 0; /*reset */
}
} else {
flow = prandom_u32() % pkt_dev->cflows;
pkt_dev->curfl = flow;
if (pkt_dev->flows[flow].count > pkt_dev->lflow) {
pkt_dev->flows[flow].count = 0;
pkt_dev->flows[flow].flags = 0;
}
}
return pkt_dev->curfl;
}
#ifdef CONFIG_XFRM
/* If there was already an IPSEC SA, we keep it as is, else
* we go look for it ...
*/
#define DUMMY_MARK 0
static void get_ipsec_sa(struct pktgen_dev *pkt_dev, int flow)
{
struct xfrm_state *x = pkt_dev->flows[flow].x;
struct pktgen_net *pn = net_generic(dev_net(pkt_dev->odev), pg_net_id);
if (!x) {
if (pkt_dev->spi) {
/* We need as quick as possible to find the right SA
* Searching with minimum criteria to archieve this.
*/
x = xfrm_state_lookup_byspi(pn->net, htonl(pkt_dev->spi), AF_INET);
} else {
/* slow path: we dont already have xfrm_state */
x = xfrm_stateonly_find(pn->net, DUMMY_MARK,
(xfrm_address_t *)&pkt_dev->cur_daddr,
(xfrm_address_t *)&pkt_dev->cur_saddr,
AF_INET,
pkt_dev->ipsmode,
pkt_dev->ipsproto, 0);
}
if (x) {
pkt_dev->flows[flow].x = x;
set_pkt_overhead(pkt_dev);
pkt_dev->pkt_overhead += x->props.header_len;
}
}
}
#endif
static void set_cur_queue_map(struct pktgen_dev *pkt_dev)
{
if (pkt_dev->flags & F_QUEUE_MAP_CPU)
pkt_dev->cur_queue_map = smp_processor_id();
else if (pkt_dev->queue_map_min <= pkt_dev->queue_map_max) {
__u16 t;
if (pkt_dev->flags & F_QUEUE_MAP_RND) {
t = prandom_u32() %
(pkt_dev->queue_map_max -
pkt_dev->queue_map_min + 1)
+ pkt_dev->queue_map_min;
} else {
t = pkt_dev->cur_queue_map + 1;
if (t > pkt_dev->queue_map_max)
t = pkt_dev->queue_map_min;
}
pkt_dev->cur_queue_map = t;
}
pkt_dev->cur_queue_map = pkt_dev->cur_queue_map % pkt_dev->odev->real_num_tx_queues;
}
/* Increment/randomize headers according to flags and current values
* for IP src/dest, UDP src/dst port, MAC-Addr src/dst
*/
static void mod_cur_headers(struct pktgen_dev *pkt_dev)
{
__u32 imn;
__u32 imx;
int flow = 0;
if (pkt_dev->cflows)
flow = f_pick(pkt_dev);
/* Deal with source MAC */
if (pkt_dev->src_mac_count > 1) {
__u32 mc;
__u32 tmp;
if (pkt_dev->flags & F_MACSRC_RND)
mc = prandom_u32() % pkt_dev->src_mac_count;
else {
mc = pkt_dev->cur_src_mac_offset++;
if (pkt_dev->cur_src_mac_offset >=
pkt_dev->src_mac_count)
pkt_dev->cur_src_mac_offset = 0;
}
tmp = pkt_dev->src_mac[5] + (mc & 0xFF);
pkt_dev->hh[11] = tmp;
tmp = (pkt_dev->src_mac[4] + ((mc >> 8) & 0xFF) + (tmp >> 8));
pkt_dev->hh[10] = tmp;
tmp = (pkt_dev->src_mac[3] + ((mc >> 16) & 0xFF) + (tmp >> 8));
pkt_dev->hh[9] = tmp;
tmp = (pkt_dev->src_mac[2] + ((mc >> 24) & 0xFF) + (tmp >> 8));
pkt_dev->hh[8] = tmp;
tmp = (pkt_dev->src_mac[1] + (tmp >> 8));
pkt_dev->hh[7] = tmp;
}
/* Deal with Destination MAC */
if (pkt_dev->dst_mac_count > 1) {
__u32 mc;
__u32 tmp;
if (pkt_dev->flags & F_MACDST_RND)
mc = prandom_u32() % pkt_dev->dst_mac_count;
else {
mc = pkt_dev->cur_dst_mac_offset++;
if (pkt_dev->cur_dst_mac_offset >=
pkt_dev->dst_mac_count) {
pkt_dev->cur_dst_mac_offset = 0;
}
}
tmp = pkt_dev->dst_mac[5] + (mc & 0xFF);
pkt_dev->hh[5] = tmp;
tmp = (pkt_dev->dst_mac[4] + ((mc >> 8) & 0xFF) + (tmp >> 8));
pkt_dev->hh[4] = tmp;
tmp = (pkt_dev->dst_mac[3] + ((mc >> 16) & 0xFF) + (tmp >> 8));
pkt_dev->hh[3] = tmp;
tmp = (pkt_dev->dst_mac[2] + ((mc >> 24) & 0xFF) + (tmp >> 8));
pkt_dev->hh[2] = tmp;
tmp = (pkt_dev->dst_mac[1] + (tmp >> 8));
pkt_dev->hh[1] = tmp;
}
if (pkt_dev->flags & F_MPLS_RND) {
unsigned int i;
for (i = 0; i < pkt_dev->nr_labels; i++)
if (pkt_dev->labels[i] & MPLS_STACK_BOTTOM)
pkt_dev->labels[i] = MPLS_STACK_BOTTOM |
((__force __be32)prandom_u32() &
htonl(0x000fffff));
}
if ((pkt_dev->flags & F_VID_RND) && (pkt_dev->vlan_id != 0xffff)) {
pkt_dev->vlan_id = prandom_u32() & (4096 - 1);
}
if ((pkt_dev->flags & F_SVID_RND) && (pkt_dev->svlan_id != 0xffff)) {
pkt_dev->svlan_id = prandom_u32() & (4096 - 1);
}
if (pkt_dev->udp_src_min < pkt_dev->udp_src_max) {
if (pkt_dev->flags & F_UDPSRC_RND)
pkt_dev->cur_udp_src = prandom_u32() %
(pkt_dev->udp_src_max - pkt_dev->udp_src_min)
+ pkt_dev->udp_src_min;
else {
pkt_dev->cur_udp_src++;
if (pkt_dev->cur_udp_src >= pkt_dev->udp_src_max)
pkt_dev->cur_udp_src = pkt_dev->udp_src_min;
}
}
if (pkt_dev->udp_dst_min < pkt_dev->udp_dst_max) {
if (pkt_dev->flags & F_UDPDST_RND) {
pkt_dev->cur_udp_dst = prandom_u32() %
(pkt_dev->udp_dst_max - pkt_dev->udp_dst_min)
+ pkt_dev->udp_dst_min;
} else {
pkt_dev->cur_udp_dst++;
if (pkt_dev->cur_udp_dst >= pkt_dev->udp_dst_max)
pkt_dev->cur_udp_dst = pkt_dev->udp_dst_min;
}
}
if (!(pkt_dev->flags & F_IPV6)) {
imn = ntohl(pkt_dev->saddr_min);
imx = ntohl(pkt_dev->saddr_max);
if (imn < imx) {
__u32 t;
if (pkt_dev->flags & F_IPSRC_RND)
t = prandom_u32() % (imx - imn) + imn;
else {
t = ntohl(pkt_dev->cur_saddr);
t++;
if (t > imx)
t = imn;
}
pkt_dev->cur_saddr = htonl(t);
}
if (pkt_dev->cflows && f_seen(pkt_dev, flow)) {
pkt_dev->cur_daddr = pkt_dev->flows[flow].cur_daddr;
} else {
imn = ntohl(pkt_dev->daddr_min);
imx = ntohl(pkt_dev->daddr_max);
if (imn < imx) {
__u32 t;
__be32 s;
if (pkt_dev->flags & F_IPDST_RND) {
do {
t = prandom_u32() %
(imx - imn) + imn;
s = htonl(t);
} while (ipv4_is_loopback(s) ||
ipv4_is_multicast(s) ||
ipv4_is_lbcast(s) ||
ipv4_is_zeronet(s) ||
ipv4_is_local_multicast(s));
pkt_dev->cur_daddr = s;
} else {
t = ntohl(pkt_dev->cur_daddr);
t++;
if (t > imx) {
t = imn;
}
pkt_dev->cur_daddr = htonl(t);
}
}
if (pkt_dev->cflows) {
pkt_dev->flows[flow].flags |= F_INIT;
pkt_dev->flows[flow].cur_daddr =
pkt_dev->cur_daddr;
#ifdef CONFIG_XFRM
if (pkt_dev->flags & F_IPSEC_ON)
get_ipsec_sa(pkt_dev, flow);
#endif
pkt_dev->nflows++;
}
}
} else { /* IPV6 * */
if (!ipv6_addr_any(&pkt_dev->min_in6_daddr)) {
int i;
/* Only random destinations yet */
for (i = 0; i < 4; i++) {
pkt_dev->cur_in6_daddr.s6_addr32[i] =
(((__force __be32)prandom_u32() |
pkt_dev->min_in6_daddr.s6_addr32[i]) &
pkt_dev->max_in6_daddr.s6_addr32[i]);
}
}
}
if (pkt_dev->min_pkt_size < pkt_dev->max_pkt_size) {
__u32 t;
if (pkt_dev->flags & F_TXSIZE_RND) {
t = prandom_u32() %
(pkt_dev->max_pkt_size - pkt_dev->min_pkt_size)
+ pkt_dev->min_pkt_size;
} else {
t = pkt_dev->cur_pkt_size + 1;
if (t > pkt_dev->max_pkt_size)
t = pkt_dev->min_pkt_size;
}
pkt_dev->cur_pkt_size = t;
}
set_cur_queue_map(pkt_dev);
pkt_dev->flows[flow].count++;
}
#ifdef CONFIG_XFRM
static u32 pktgen_dst_metrics[RTAX_MAX + 1] = {
[RTAX_HOPLIMIT] = 0x5, /* Set a static hoplimit */
};
static int pktgen_output_ipsec(struct sk_buff *skb, struct pktgen_dev *pkt_dev)
{
struct xfrm_state *x = pkt_dev->flows[pkt_dev->curfl].x;
int err = 0;
struct net *net = dev_net(pkt_dev->odev);
if (!x)
return 0;
/* XXX: we dont support tunnel mode for now until
* we resolve the dst issue */
if ((x->props.mode != XFRM_MODE_TRANSPORT) && (pkt_dev->spi == 0))
return 0;
/* But when user specify an valid SPI, transformation
* supports both transport/tunnel mode + ESP/AH type.
*/
if ((x->props.mode == XFRM_MODE_TUNNEL) && (pkt_dev->spi != 0))
skb->_skb_refdst = (unsigned long)&pkt_dev->dst | SKB_DST_NOREF;
rcu_read_lock_bh();
err = x->outer_mode->output(x, skb);
rcu_read_unlock_bh();
if (err) {
XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
goto error;
}
err = x->type->output(x, skb);
if (err) {
XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
goto error;
}
{pktgen, xfrm} Correct xfrm state lock usage when transforming xfrm_state lock protects its state, i.e., VALID/DEAD and statistics, not the transforming procedure, as both mode/type output functions are reentrant. Another issue is state lock can be used in BH context when state timer alarmed, after transformation in pktgen, update state statistics acquiring state lock should disabled BH context for a moment. Otherwise LOCKDEP critisize this: [ 62.354339] pktgen: Packet Generator for packet performance testing. Version: 2.74 [ 62.655444] [ 62.655448] ================================= [ 62.655451] [ INFO: inconsistent lock state ] [ 62.655455] 3.13.0-rc2+ #70 Not tainted [ 62.655457] --------------------------------- [ 62.655459] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 62.655463] kpktgend_0/2764 [HC0[0]:SC0[0]:HE1:SE1] takes: [ 62.655466] (&(&x->lock)->rlock){+.?...}, at: [<ffffffffa00886f6>] pktgen_thread_worker+0x1796/0x1860 [pktgen] [ 62.655479] {IN-SOFTIRQ-W} state was registered at: [ 62.655484] [<ffffffff8109a61d>] __lock_acquire+0x62d/0x1d70 [ 62.655492] [<ffffffff8109c3c7>] lock_acquire+0x97/0x130 [ 62.655498] [<ffffffff81774af6>] _raw_spin_lock+0x36/0x70 [ 62.655505] [<ffffffff816dc3a3>] xfrm_timer_handler+0x43/0x290 [ 62.655511] [<ffffffff81059437>] __tasklet_hrtimer_trampoline+0x17/0x40 [ 62.655519] [<ffffffff8105a1b7>] tasklet_hi_action+0xd7/0xf0 [ 62.655523] [<ffffffff81059ac6>] __do_softirq+0xe6/0x2d0 [ 62.655526] [<ffffffff8105a026>] irq_exit+0x96/0xc0 [ 62.655530] [<ffffffff8177fd0a>] smp_apic_timer_interrupt+0x4a/0x60 [ 62.655537] [<ffffffff8177e96f>] apic_timer_interrupt+0x6f/0x80 [ 62.655541] [<ffffffff8100b7c6>] arch_cpu_idle+0x26/0x30 [ 62.655547] [<ffffffff810ace28>] cpu_startup_entry+0x88/0x2b0 [ 62.655552] [<ffffffff81761c3c>] rest_init+0xbc/0xd0 [ 62.655557] [<ffffffff81ea5e5e>] start_kernel+0x3c4/0x3d1 [ 62.655583] [<ffffffff81ea55a8>] x86_64_start_reservations+0x2a/0x2c [ 62.655588] [<ffffffff81ea569f>] x86_64_start_kernel+0xf5/0xfc [ 62.655592] irq event stamp: 77 [ 62.655594] hardirqs last enabled at (77): [<ffffffff810ab7f2>] vprintk_emit+0x1b2/0x520 [ 62.655597] hardirqs last disabled at (76): [<ffffffff810ab684>] vprintk_emit+0x44/0x520 [ 62.655601] softirqs last enabled at (22): [<ffffffff81059b57>] __do_softirq+0x177/0x2d0 [ 62.655605] softirqs last disabled at (15): [<ffffffff8105a026>] irq_exit+0x96/0xc0 [ 62.655609] [ 62.655609] other info that might help us debug this: [ 62.655613] Possible unsafe locking scenario: [ 62.655613] [ 62.655616] CPU0 [ 62.655617] ---- [ 62.655618] lock(&(&x->lock)->rlock); [ 62.655622] <Interrupt> [ 62.655623] lock(&(&x->lock)->rlock); [ 62.655626] [ 62.655626] *** DEADLOCK *** [ 62.655626] [ 62.655629] no locks held by kpktgend_0/2764. [ 62.655631] [ 62.655631] stack backtrace: [ 62.655636] CPU: 0 PID: 2764 Comm: kpktgend_0 Not tainted 3.13.0-rc2+ #70 [ 62.655638] Hardware name: innotek GmbH VirtualBox, BIOS VirtualBox 12/01/2006 [ 62.655642] ffffffff8216b7b0 ffff88001be43ab8 ffffffff8176af37 0000000000000007 [ 62.655652] ffff88001c8d4fc0 ffff88001be43b18 ffffffff81766d78 0000000000000000 [ 62.655663] ffff880000000001 ffff880000000001 ffffffff8101025f ffff88001be43b18 [ 62.655671] Call Trace: [ 62.655680] [<ffffffff8176af37>] dump_stack+0x46/0x58 [ 62.655685] [<ffffffff81766d78>] print_usage_bug+0x1f1/0x202 [ 62.655691] [<ffffffff8101025f>] ? save_stack_trace+0x2f/0x50 [ 62.655696] [<ffffffff81099f8c>] mark_lock+0x28c/0x2f0 [ 62.655700] [<ffffffff810994b0>] ? check_usage_forwards+0x150/0x150 [ 62.655704] [<ffffffff8109a67a>] __lock_acquire+0x68a/0x1d70 [ 62.655712] [<ffffffff81115b09>] ? irq_work_queue+0x69/0xb0 [ 62.655717] [<ffffffff810ab7f2>] ? vprintk_emit+0x1b2/0x520 [ 62.655722] [<ffffffff8109cec5>] ? trace_hardirqs_on_caller+0x105/0x1d0 [ 62.655730] [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen] [ 62.655734] [<ffffffff8109c3c7>] lock_acquire+0x97/0x130 [ 62.655741] [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen] [ 62.655745] [<ffffffff81774af6>] _raw_spin_lock+0x36/0x70 [ 62.655752] [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen] [ 62.655758] [<ffffffffa00886f6>] pktgen_thread_worker+0x1796/0x1860 [pktgen] [ 62.655766] [<ffffffffa0087a79>] ? pktgen_thread_worker+0xb19/0x1860 [pktgen] [ 62.655771] [<ffffffff8109cf9d>] ? trace_hardirqs_on+0xd/0x10 [ 62.655777] [<ffffffff81775410>] ? _raw_spin_unlock_irq+0x30/0x40 [ 62.655785] [<ffffffff8151faa0>] ? e1000_clean+0x9d0/0x9d0 [ 62.655791] [<ffffffff81094310>] ? __init_waitqueue_head+0x60/0x60 [ 62.655795] [<ffffffff81094310>] ? __init_waitqueue_head+0x60/0x60 [ 62.655800] [<ffffffffa0086f60>] ? mod_cur_headers+0x7f0/0x7f0 [pktgen] [ 62.655806] [<ffffffff81078f84>] kthread+0xe4/0x100 [ 62.655813] [<ffffffff81078ea0>] ? flush_kthread_worker+0x170/0x170 [ 62.655819] [<ffffffff8177dc6c>] ret_from_fork+0x7c/0xb0 [ 62.655824] [<ffffffff81078ea0>] ? flush_kthread_worker+0x170/0x170 Signed-off-by: Fan Du <fan.du@windriver.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2014-01-03 11:18:27 +08:00
spin_lock_bh(&x->lock);
x->curlft.bytes += skb->len;
x->curlft.packets++;
{pktgen, xfrm} Correct xfrm state lock usage when transforming xfrm_state lock protects its state, i.e., VALID/DEAD and statistics, not the transforming procedure, as both mode/type output functions are reentrant. Another issue is state lock can be used in BH context when state timer alarmed, after transformation in pktgen, update state statistics acquiring state lock should disabled BH context for a moment. Otherwise LOCKDEP critisize this: [ 62.354339] pktgen: Packet Generator for packet performance testing. Version: 2.74 [ 62.655444] [ 62.655448] ================================= [ 62.655451] [ INFO: inconsistent lock state ] [ 62.655455] 3.13.0-rc2+ #70 Not tainted [ 62.655457] --------------------------------- [ 62.655459] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 62.655463] kpktgend_0/2764 [HC0[0]:SC0[0]:HE1:SE1] takes: [ 62.655466] (&(&x->lock)->rlock){+.?...}, at: [<ffffffffa00886f6>] pktgen_thread_worker+0x1796/0x1860 [pktgen] [ 62.655479] {IN-SOFTIRQ-W} state was registered at: [ 62.655484] [<ffffffff8109a61d>] __lock_acquire+0x62d/0x1d70 [ 62.655492] [<ffffffff8109c3c7>] lock_acquire+0x97/0x130 [ 62.655498] [<ffffffff81774af6>] _raw_spin_lock+0x36/0x70 [ 62.655505] [<ffffffff816dc3a3>] xfrm_timer_handler+0x43/0x290 [ 62.655511] [<ffffffff81059437>] __tasklet_hrtimer_trampoline+0x17/0x40 [ 62.655519] [<ffffffff8105a1b7>] tasklet_hi_action+0xd7/0xf0 [ 62.655523] [<ffffffff81059ac6>] __do_softirq+0xe6/0x2d0 [ 62.655526] [<ffffffff8105a026>] irq_exit+0x96/0xc0 [ 62.655530] [<ffffffff8177fd0a>] smp_apic_timer_interrupt+0x4a/0x60 [ 62.655537] [<ffffffff8177e96f>] apic_timer_interrupt+0x6f/0x80 [ 62.655541] [<ffffffff8100b7c6>] arch_cpu_idle+0x26/0x30 [ 62.655547] [<ffffffff810ace28>] cpu_startup_entry+0x88/0x2b0 [ 62.655552] [<ffffffff81761c3c>] rest_init+0xbc/0xd0 [ 62.655557] [<ffffffff81ea5e5e>] start_kernel+0x3c4/0x3d1 [ 62.655583] [<ffffffff81ea55a8>] x86_64_start_reservations+0x2a/0x2c [ 62.655588] [<ffffffff81ea569f>] x86_64_start_kernel+0xf5/0xfc [ 62.655592] irq event stamp: 77 [ 62.655594] hardirqs last enabled at (77): [<ffffffff810ab7f2>] vprintk_emit+0x1b2/0x520 [ 62.655597] hardirqs last disabled at (76): [<ffffffff810ab684>] vprintk_emit+0x44/0x520 [ 62.655601] softirqs last enabled at (22): [<ffffffff81059b57>] __do_softirq+0x177/0x2d0 [ 62.655605] softirqs last disabled at (15): [<ffffffff8105a026>] irq_exit+0x96/0xc0 [ 62.655609] [ 62.655609] other info that might help us debug this: [ 62.655613] Possible unsafe locking scenario: [ 62.655613] [ 62.655616] CPU0 [ 62.655617] ---- [ 62.655618] lock(&(&x->lock)->rlock); [ 62.655622] <Interrupt> [ 62.655623] lock(&(&x->lock)->rlock); [ 62.655626] [ 62.655626] *** DEADLOCK *** [ 62.655626] [ 62.655629] no locks held by kpktgend_0/2764. [ 62.655631] [ 62.655631] stack backtrace: [ 62.655636] CPU: 0 PID: 2764 Comm: kpktgend_0 Not tainted 3.13.0-rc2+ #70 [ 62.655638] Hardware name: innotek GmbH VirtualBox, BIOS VirtualBox 12/01/2006 [ 62.655642] ffffffff8216b7b0 ffff88001be43ab8 ffffffff8176af37 0000000000000007 [ 62.655652] ffff88001c8d4fc0 ffff88001be43b18 ffffffff81766d78 0000000000000000 [ 62.655663] ffff880000000001 ffff880000000001 ffffffff8101025f ffff88001be43b18 [ 62.655671] Call Trace: [ 62.655680] [<ffffffff8176af37>] dump_stack+0x46/0x58 [ 62.655685] [<ffffffff81766d78>] print_usage_bug+0x1f1/0x202 [ 62.655691] [<ffffffff8101025f>] ? save_stack_trace+0x2f/0x50 [ 62.655696] [<ffffffff81099f8c>] mark_lock+0x28c/0x2f0 [ 62.655700] [<ffffffff810994b0>] ? check_usage_forwards+0x150/0x150 [ 62.655704] [<ffffffff8109a67a>] __lock_acquire+0x68a/0x1d70 [ 62.655712] [<ffffffff81115b09>] ? irq_work_queue+0x69/0xb0 [ 62.655717] [<ffffffff810ab7f2>] ? vprintk_emit+0x1b2/0x520 [ 62.655722] [<ffffffff8109cec5>] ? trace_hardirqs_on_caller+0x105/0x1d0 [ 62.655730] [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen] [ 62.655734] [<ffffffff8109c3c7>] lock_acquire+0x97/0x130 [ 62.655741] [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen] [ 62.655745] [<ffffffff81774af6>] _raw_spin_lock+0x36/0x70 [ 62.655752] [<ffffffffa00886f6>] ? pktgen_thread_worker+0x1796/0x1860 [pktgen] [ 62.655758] [<ffffffffa00886f6>] pktgen_thread_worker+0x1796/0x1860 [pktgen] [ 62.655766] [<ffffffffa0087a79>] ? pktgen_thread_worker+0xb19/0x1860 [pktgen] [ 62.655771] [<ffffffff8109cf9d>] ? trace_hardirqs_on+0xd/0x10 [ 62.655777] [<ffffffff81775410>] ? _raw_spin_unlock_irq+0x30/0x40 [ 62.655785] [<ffffffff8151faa0>] ? e1000_clean+0x9d0/0x9d0 [ 62.655791] [<ffffffff81094310>] ? __init_waitqueue_head+0x60/0x60 [ 62.655795] [<ffffffff81094310>] ? __init_waitqueue_head+0x60/0x60 [ 62.655800] [<ffffffffa0086f60>] ? mod_cur_headers+0x7f0/0x7f0 [pktgen] [ 62.655806] [<ffffffff81078f84>] kthread+0xe4/0x100 [ 62.655813] [<ffffffff81078ea0>] ? flush_kthread_worker+0x170/0x170 [ 62.655819] [<ffffffff8177dc6c>] ret_from_fork+0x7c/0xb0 [ 62.655824] [<ffffffff81078ea0>] ? flush_kthread_worker+0x170/0x170 Signed-off-by: Fan Du <fan.du@windriver.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2014-01-03 11:18:27 +08:00
spin_unlock_bh(&x->lock);
error:
return err;
}
static void free_SAs(struct pktgen_dev *pkt_dev)
{
if (pkt_dev->cflows) {
/* let go of the SAs if we have them */
int i;
for (i = 0; i < pkt_dev->cflows; i++) {
struct xfrm_state *x = pkt_dev->flows[i].x;
if (x) {
xfrm_state_put(x);
pkt_dev->flows[i].x = NULL;
}
}
}
}
static int process_ipsec(struct pktgen_dev *pkt_dev,
struct sk_buff *skb, __be16 protocol)
{
if (pkt_dev->flags & F_IPSEC_ON) {
struct xfrm_state *x = pkt_dev->flows[pkt_dev->curfl].x;
int nhead = 0;
if (x) {
int ret;
__u8 *eth;
struct iphdr *iph;
nhead = x->props.header_len - skb_headroom(skb);
if (nhead > 0) {
ret = pskb_expand_head(skb, nhead, 0, GFP_ATOMIC);
if (ret < 0) {
pr_err("Error expanding ipsec packet %d\n",
ret);
goto err;
}
}
/* ipsec is not expecting ll header */
skb_pull(skb, ETH_HLEN);
ret = pktgen_output_ipsec(skb, pkt_dev);
if (ret) {
pr_err("Error creating ipsec packet %d\n", ret);
goto err;
}
/* restore ll */
eth = (__u8 *) skb_push(skb, ETH_HLEN);
memcpy(eth, pkt_dev->hh, 12);
*(u16 *) &eth[12] = protocol;
/* Update IPv4 header len as well as checksum value */
iph = ip_hdr(skb);
iph->tot_len = htons(skb->len - ETH_HLEN);
ip_send_check(iph);
}
}
return 1;
err:
kfree_skb(skb);
return 0;
}
#endif
static void mpls_push(__be32 *mpls, struct pktgen_dev *pkt_dev)
{
unsigned int i;
for (i = 0; i < pkt_dev->nr_labels; i++)
*mpls++ = pkt_dev->labels[i] & ~MPLS_STACK_BOTTOM;
mpls--;
*mpls |= MPLS_STACK_BOTTOM;
}
static inline __be16 build_tci(unsigned int id, unsigned int cfi,
unsigned int prio)
{
return htons(id | (cfi << 12) | (prio << 13));
}
static void pktgen_finalize_skb(struct pktgen_dev *pkt_dev, struct sk_buff *skb,
int datalen)
{
struct timeval timestamp;
struct pktgen_hdr *pgh;
pgh = (struct pktgen_hdr *)skb_put(skb, sizeof(*pgh));
datalen -= sizeof(*pgh);
if (pkt_dev->nfrags <= 0) {
memset(skb_put(skb, datalen), 0, datalen);
} else {
int frags = pkt_dev->nfrags;
int i, len;
int frag_len;
if (frags > MAX_SKB_FRAGS)
frags = MAX_SKB_FRAGS;
len = datalen - frags * PAGE_SIZE;
if (len > 0) {
memset(skb_put(skb, len), 0, len);
datalen = frags * PAGE_SIZE;
}
i = 0;
frag_len = (datalen/frags) < PAGE_SIZE ?
(datalen/frags) : PAGE_SIZE;
while (datalen > 0) {
if (unlikely(!pkt_dev->page)) {
int node = numa_node_id();
if (pkt_dev->node >= 0 && (pkt_dev->flags & F_NODE))
node = pkt_dev->node;
pkt_dev->page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
if (!pkt_dev->page)
break;
}
get_page(pkt_dev->page);
skb_frag_set_page(skb, i, pkt_dev->page);
skb_shinfo(skb)->frags[i].page_offset = 0;
/*last fragment, fill rest of data*/
if (i == (frags - 1))
skb_frag_size_set(&skb_shinfo(skb)->frags[i],
(datalen < PAGE_SIZE ? datalen : PAGE_SIZE));
else
skb_frag_size_set(&skb_shinfo(skb)->frags[i], frag_len);
datalen -= skb_frag_size(&skb_shinfo(skb)->frags[i]);
skb->len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
skb->data_len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
i++;
skb_shinfo(skb)->nr_frags = i;
}
}
/* Stamp the time, and sequence number,
* convert them to network byte order
*/
pgh->pgh_magic = htonl(PKTGEN_MAGIC);
pgh->seq_num = htonl(pkt_dev->seq_num);
do_gettimeofday(&timestamp);
pgh->tv_sec = htonl(timestamp.tv_sec);
pgh->tv_usec = htonl(timestamp.tv_usec);
}
static struct sk_buff *pktgen_alloc_skb(struct net_device *dev,
struct pktgen_dev *pkt_dev,
unsigned int extralen)
{
struct sk_buff *skb = NULL;
unsigned int size = pkt_dev->cur_pkt_size + 64 + extralen +
pkt_dev->pkt_overhead;
if (pkt_dev->flags & F_NODE) {
int node = pkt_dev->node >= 0 ? pkt_dev->node : numa_node_id();
skb = __alloc_skb(NET_SKB_PAD + size, GFP_NOWAIT, 0, node);
if (likely(skb)) {
skb_reserve(skb, NET_SKB_PAD);
skb->dev = dev;
}
} else {
skb = __netdev_alloc_skb(dev, size, GFP_NOWAIT);
}
return skb;
}
static struct sk_buff *fill_packet_ipv4(struct net_device *odev,
struct pktgen_dev *pkt_dev)
{
struct sk_buff *skb = NULL;
__u8 *eth;
struct udphdr *udph;
int datalen, iplen;
struct iphdr *iph;
__be16 protocol = htons(ETH_P_IP);
__be32 *mpls;
__be16 *vlan_tci = NULL; /* Encapsulates priority and VLAN ID */
__be16 *vlan_encapsulated_proto = NULL; /* packet type ID field (or len) for VLAN tag */
__be16 *svlan_tci = NULL; /* Encapsulates priority and SVLAN ID */
__be16 *svlan_encapsulated_proto = NULL; /* packet type ID field (or len) for SVLAN tag */
u16 queue_map;
if (pkt_dev->nr_labels)
protocol = htons(ETH_P_MPLS_UC);
if (pkt_dev->vlan_id != 0xffff)
protocol = htons(ETH_P_8021Q);
/* Update any of the values, used when we're incrementing various
* fields.
*/
mod_cur_headers(pkt_dev);
queue_map = pkt_dev->cur_queue_map;
datalen = (odev->hard_header_len + 16) & ~0xf;
skb = pktgen_alloc_skb(odev, pkt_dev, datalen);
if (!skb) {
sprintf(pkt_dev->result, "No memory");
return NULL;
}
prefetchw(skb->data);
skb_reserve(skb, datalen);
/* Reserve for ethernet and IP header */
eth = (__u8 *) skb_push(skb, 14);
mpls = (__be32 *)skb_put(skb, pkt_dev->nr_labels*sizeof(__u32));
if (pkt_dev->nr_labels)
mpls_push(mpls, pkt_dev);
if (pkt_dev->vlan_id != 0xffff) {
if (pkt_dev->svlan_id != 0xffff) {
svlan_tci = (__be16 *)skb_put(skb, sizeof(__be16));
*svlan_tci = build_tci(pkt_dev->svlan_id,
pkt_dev->svlan_cfi,
pkt_dev->svlan_p);
svlan_encapsulated_proto = (__be16 *)skb_put(skb, sizeof(__be16));
*svlan_encapsulated_proto = htons(ETH_P_8021Q);
}
vlan_tci = (__be16 *)skb_put(skb, sizeof(__be16));
*vlan_tci = build_tci(pkt_dev->vlan_id,
pkt_dev->vlan_cfi,
pkt_dev->vlan_p);
vlan_encapsulated_proto = (__be16 *)skb_put(skb, sizeof(__be16));
*vlan_encapsulated_proto = htons(ETH_P_IP);
}
skb_set_mac_header(skb, 0);
skb_set_network_header(skb, skb->len);
iph = (struct iphdr *) skb_put(skb, sizeof(struct iphdr));
skb_set_transport_header(skb, skb->len);
udph = (struct udphdr *) skb_put(skb, sizeof(struct udphdr));
skb_set_queue_mapping(skb, queue_map);
skb->priority = pkt_dev->skb_priority;
memcpy(eth, pkt_dev->hh, 12);
*(__be16 *) & eth[12] = protocol;
/* Eth + IPh + UDPh + mpls */
datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 -
pkt_dev->pkt_overhead;
if (datalen < 0 || datalen < sizeof(struct pktgen_hdr))
datalen = sizeof(struct pktgen_hdr);
udph->source = htons(pkt_dev->cur_udp_src);
udph->dest = htons(pkt_dev->cur_udp_dst);
udph->len = htons(datalen + 8); /* DATA + udphdr */
udph->check = 0;
iph->ihl = 5;
iph->version = 4;
iph->ttl = 32;
iph->tos = pkt_dev->tos;
iph->protocol = IPPROTO_UDP; /* UDP */
iph->saddr = pkt_dev->cur_saddr;
iph->daddr = pkt_dev->cur_daddr;
iph->id = htons(pkt_dev->ip_id);
pkt_dev->ip_id++;
iph->frag_off = 0;
iplen = 20 + 8 + datalen;
iph->tot_len = htons(iplen);
ip_send_check(iph);
skb->protocol = protocol;
skb->dev = odev;
skb->pkt_type = PACKET_HOST;
if (!(pkt_dev->flags & F_UDPCSUM)) {
skb->ip_summed = CHECKSUM_NONE;
} else if (odev->features & NETIF_F_V4_CSUM) {
skb->ip_summed = CHECKSUM_PARTIAL;
skb->csum = 0;
udp4_hwcsum(skb, udph->source, udph->dest);
} else {
__wsum csum = udp_csum(skb);
/* add protocol-dependent pseudo-header */
udph->check = csum_tcpudp_magic(udph->source, udph->dest,
datalen + 8, IPPROTO_UDP, csum);
if (udph->check == 0)
udph->check = CSUM_MANGLED_0;
}
pktgen_finalize_skb(pkt_dev, skb, datalen);
#ifdef CONFIG_XFRM
if (!process_ipsec(pkt_dev, skb, protocol))
return NULL;
#endif
return skb;
}
static struct sk_buff *fill_packet_ipv6(struct net_device *odev,
struct pktgen_dev *pkt_dev)
{
struct sk_buff *skb = NULL;
__u8 *eth;
struct udphdr *udph;
int datalen, udplen;
struct ipv6hdr *iph;
__be16 protocol = htons(ETH_P_IPV6);
__be32 *mpls;
__be16 *vlan_tci = NULL; /* Encapsulates priority and VLAN ID */
__be16 *vlan_encapsulated_proto = NULL; /* packet type ID field (or len) for VLAN tag */
__be16 *svlan_tci = NULL; /* Encapsulates priority and SVLAN ID */
__be16 *svlan_encapsulated_proto = NULL; /* packet type ID field (or len) for SVLAN tag */
u16 queue_map;
if (pkt_dev->nr_labels)
protocol = htons(ETH_P_MPLS_UC);
if (pkt_dev->vlan_id != 0xffff)
protocol = htons(ETH_P_8021Q);
/* Update any of the values, used when we're incrementing various
* fields.
*/
mod_cur_headers(pkt_dev);
queue_map = pkt_dev->cur_queue_map;
skb = pktgen_alloc_skb(odev, pkt_dev, 16);
if (!skb) {
sprintf(pkt_dev->result, "No memory");
return NULL;
}
prefetchw(skb->data);
skb_reserve(skb, 16);
/* Reserve for ethernet and IP header */
eth = (__u8 *) skb_push(skb, 14);
mpls = (__be32 *)skb_put(skb, pkt_dev->nr_labels*sizeof(__u32));
if (pkt_dev->nr_labels)
mpls_push(mpls, pkt_dev);
if (pkt_dev->vlan_id != 0xffff) {
if (pkt_dev->svlan_id != 0xffff) {
svlan_tci = (__be16 *)skb_put(skb, sizeof(__be16));
*svlan_tci = build_tci(pkt_dev->svlan_id,
pkt_dev->svlan_cfi,
pkt_dev->svlan_p);
svlan_encapsulated_proto = (__be16 *)skb_put(skb, sizeof(__be16));
*svlan_encapsulated_proto = htons(ETH_P_8021Q);
}
vlan_tci = (__be16 *)skb_put(skb, sizeof(__be16));
*vlan_tci = build_tci(pkt_dev->vlan_id,
pkt_dev->vlan_cfi,
pkt_dev->vlan_p);
vlan_encapsulated_proto = (__be16 *)skb_put(skb, sizeof(__be16));
*vlan_encapsulated_proto = htons(ETH_P_IPV6);
}
skb_set_mac_header(skb, 0);
skb_set_network_header(skb, skb->len);
iph = (struct ipv6hdr *) skb_put(skb, sizeof(struct ipv6hdr));
skb_set_transport_header(skb, skb->len);
udph = (struct udphdr *) skb_put(skb, sizeof(struct udphdr));
skb_set_queue_mapping(skb, queue_map);
skb->priority = pkt_dev->skb_priority;
memcpy(eth, pkt_dev->hh, 12);
*(__be16 *) &eth[12] = protocol;
/* Eth + IPh + UDPh + mpls */
datalen = pkt_dev->cur_pkt_size - 14 -
sizeof(struct ipv6hdr) - sizeof(struct udphdr) -
pkt_dev->pkt_overhead;
if (datalen < 0 || datalen < sizeof(struct pktgen_hdr)) {
datalen = sizeof(struct pktgen_hdr);
net_info_ratelimited("increased datalen to %d\n", datalen);
}
udplen = datalen + sizeof(struct udphdr);
udph->source = htons(pkt_dev->cur_udp_src);
udph->dest = htons(pkt_dev->cur_udp_dst);
udph->len = htons(udplen);
udph->check = 0;
*(__be32 *) iph = htonl(0x60000000); /* Version + flow */
if (pkt_dev->traffic_class) {
/* Version + traffic class + flow (0) */
*(__be32 *)iph |= htonl(0x60000000 | (pkt_dev->traffic_class << 20));
}
iph->hop_limit = 32;
iph->payload_len = htons(udplen);
iph->nexthdr = IPPROTO_UDP;
iph->daddr = pkt_dev->cur_in6_daddr;
iph->saddr = pkt_dev->cur_in6_saddr;
skb->protocol = protocol;
skb->dev = odev;
skb->pkt_type = PACKET_HOST;
if (!(pkt_dev->flags & F_UDPCSUM)) {
skb->ip_summed = CHECKSUM_NONE;
} else if (odev->features & NETIF_F_V6_CSUM) {
skb->ip_summed = CHECKSUM_PARTIAL;
skb->csum_start = skb_transport_header(skb) - skb->head;
skb->csum_offset = offsetof(struct udphdr, check);
udph->check = ~csum_ipv6_magic(&iph->saddr, &iph->daddr, udplen, IPPROTO_UDP, 0);
} else {
__wsum csum = udp_csum(skb);
/* add protocol-dependent pseudo-header */
udph->check = csum_ipv6_magic(&iph->saddr, &iph->daddr, udplen, IPPROTO_UDP, csum);
if (udph->check == 0)
udph->check = CSUM_MANGLED_0;
}
pktgen_finalize_skb(pkt_dev, skb, datalen);
return skb;
}
static struct sk_buff *fill_packet(struct net_device *odev,
struct pktgen_dev *pkt_dev)
{
if (pkt_dev->flags & F_IPV6)
return fill_packet_ipv6(odev, pkt_dev);
else
return fill_packet_ipv4(odev, pkt_dev);
}
static void pktgen_clear_counters(struct pktgen_dev *pkt_dev)
{
pkt_dev->seq_num = 1;
pkt_dev->idle_acc = 0;
pkt_dev->sofar = 0;
pkt_dev->tx_bytes = 0;
pkt_dev->errors = 0;
}
/* Set up structure for sending pkts, clear counters */
static void pktgen_run(struct pktgen_thread *t)
{
struct pktgen_dev *pkt_dev;
int started = 0;
func_enter();
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_lock();
list_for_each_entry_rcu(pkt_dev, &t->if_list, list) {
/*
* setup odev and create initial packet.
*/
pktgen_setup_inject(pkt_dev);
if (pkt_dev->odev) {
pktgen_clear_counters(pkt_dev);
pkt_dev->skb = NULL;
pkt_dev->started_at = pkt_dev->next_tx = ktime_get();
set_pkt_overhead(pkt_dev);
strcpy(pkt_dev->result, "Starting");
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
pkt_dev->running = 1; /* Cranke yeself! */
started++;
} else
strcpy(pkt_dev->result, "Error starting");
}
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_unlock();
if (started)
t->control &= ~(T_STOP);
}
static void pktgen_stop_all_threads_ifs(struct pktgen_net *pn)
{
struct pktgen_thread *t;
func_enter();
mutex_lock(&pktgen_thread_lock);
list_for_each_entry(t, &pn->pktgen_threads, th_list)
t->control |= T_STOP;
mutex_unlock(&pktgen_thread_lock);
}
static int thread_is_running(const struct pktgen_thread *t)
{
const struct pktgen_dev *pkt_dev;
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_lock();
list_for_each_entry_rcu(pkt_dev, &t->if_list, list)
if (pkt_dev->running) {
rcu_read_unlock();
return 1;
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
}
rcu_read_unlock();
return 0;
}
static int pktgen_wait_thread_run(struct pktgen_thread *t)
{
while (thread_is_running(t)) {
msleep_interruptible(100);
if (signal_pending(current))
goto signal;
}
return 1;
signal:
return 0;
}
static int pktgen_wait_all_threads_run(struct pktgen_net *pn)
{
struct pktgen_thread *t;
int sig = 1;
mutex_lock(&pktgen_thread_lock);
list_for_each_entry(t, &pn->pktgen_threads, th_list) {
sig = pktgen_wait_thread_run(t);
if (sig == 0)
break;
}
if (sig == 0)
list_for_each_entry(t, &pn->pktgen_threads, th_list)
t->control |= (T_STOP);
mutex_unlock(&pktgen_thread_lock);
return sig;
}
static void pktgen_run_all_threads(struct pktgen_net *pn)
{
struct pktgen_thread *t;
func_enter();
mutex_lock(&pktgen_thread_lock);
list_for_each_entry(t, &pn->pktgen_threads, th_list)
t->control |= (T_RUN);
mutex_unlock(&pktgen_thread_lock);
/* Propagate thread->control */
schedule_timeout_interruptible(msecs_to_jiffies(125));
pktgen_wait_all_threads_run(pn);
}
static void pktgen_reset_all_threads(struct pktgen_net *pn)
{
struct pktgen_thread *t;
func_enter();
mutex_lock(&pktgen_thread_lock);
list_for_each_entry(t, &pn->pktgen_threads, th_list)
t->control |= (T_REMDEVALL);
mutex_unlock(&pktgen_thread_lock);
/* Propagate thread->control */
schedule_timeout_interruptible(msecs_to_jiffies(125));
pktgen_wait_all_threads_run(pn);
}
static void show_results(struct pktgen_dev *pkt_dev, int nr_frags)
{
__u64 bps, mbps, pps;
char *p = pkt_dev->result;
ktime_t elapsed = ktime_sub(pkt_dev->stopped_at,
pkt_dev->started_at);
ktime_t idle = ns_to_ktime(pkt_dev->idle_acc);
p += sprintf(p, "OK: %llu(c%llu+d%llu) usec, %llu (%dbyte,%dfrags)\n",
(unsigned long long)ktime_to_us(elapsed),
(unsigned long long)ktime_to_us(ktime_sub(elapsed, idle)),
(unsigned long long)ktime_to_us(idle),
(unsigned long long)pkt_dev->sofar,
pkt_dev->cur_pkt_size, nr_frags);
pps = div64_u64(pkt_dev->sofar * NSEC_PER_SEC,
ktime_to_ns(elapsed));
bps = pps * 8 * pkt_dev->cur_pkt_size;
mbps = bps;
do_div(mbps, 1000000);
p += sprintf(p, " %llupps %lluMb/sec (%llubps) errors: %llu",
(unsigned long long)pps,
(unsigned long long)mbps,
(unsigned long long)bps,
(unsigned long long)pkt_dev->errors);
}
/* Set stopped-at timer, remove from running list, do counters & statistics */
static int pktgen_stop_device(struct pktgen_dev *pkt_dev)
{
int nr_frags = pkt_dev->skb ? skb_shinfo(pkt_dev->skb)->nr_frags : -1;
if (!pkt_dev->running) {
pr_warning("interface: %s is already stopped\n",
pkt_dev->odevname);
return -EINVAL;
}
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
pkt_dev->running = 0;
kfree_skb(pkt_dev->skb);
pkt_dev->skb = NULL;
pkt_dev->stopped_at = ktime_get();
show_results(pkt_dev, nr_frags);
return 0;
}
static struct pktgen_dev *next_to_run(struct pktgen_thread *t)
{
struct pktgen_dev *pkt_dev, *best = NULL;
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_lock();
list_for_each_entry_rcu(pkt_dev, &t->if_list, list) {
if (!pkt_dev->running)
continue;
if (best == NULL)
best = pkt_dev;
else if (ktime_compare(pkt_dev->next_tx, best->next_tx) < 0)
best = pkt_dev;
}
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_unlock();
return best;
}
static void pktgen_stop(struct pktgen_thread *t)
{
struct pktgen_dev *pkt_dev;
func_enter();
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_lock();
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
list_for_each_entry_rcu(pkt_dev, &t->if_list, list) {
pktgen_stop_device(pkt_dev);
}
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_unlock();
}
/*
* one of our devices needs to be removed - find it
* and remove it
*/
static void pktgen_rem_one_if(struct pktgen_thread *t)
{
struct list_head *q, *n;
struct pktgen_dev *cur;
func_enter();
list_for_each_safe(q, n, &t->if_list) {
cur = list_entry(q, struct pktgen_dev, list);
if (!cur->removal_mark)
continue;
kfree_skb(cur->skb);
cur->skb = NULL;
pktgen_remove_device(t, cur);
break;
}
}
static void pktgen_rem_all_ifs(struct pktgen_thread *t)
{
struct list_head *q, *n;
struct pktgen_dev *cur;
func_enter();
/* Remove all devices, free mem */
list_for_each_safe(q, n, &t->if_list) {
cur = list_entry(q, struct pktgen_dev, list);
kfree_skb(cur->skb);
cur->skb = NULL;
pktgen_remove_device(t, cur);
}
}
static void pktgen_rem_thread(struct pktgen_thread *t)
{
/* Remove from the thread list */
remove_proc_entry(t->tsk->comm, t->net->proc_dir);
}
static void pktgen_resched(struct pktgen_dev *pkt_dev)
{
ktime_t idle_start = ktime_get();
schedule();
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(ktime_get(), idle_start));
}
static void pktgen_wait_for_skb(struct pktgen_dev *pkt_dev)
{
ktime_t idle_start = ktime_get();
while (atomic_read(&(pkt_dev->skb->users)) != 1) {
if (signal_pending(current))
break;
if (need_resched())
pktgen_resched(pkt_dev);
else
cpu_relax();
}
pkt_dev->idle_acc += ktime_to_ns(ktime_sub(ktime_get(), idle_start));
}
static void pktgen_xmit(struct pktgen_dev *pkt_dev)
{
struct net_device *odev = pkt_dev->odev;
struct netdev_queue *txq;
u16 queue_map;
int ret;
/* If device is offline, then don't send */
if (unlikely(!netif_running(odev) || !netif_carrier_ok(odev))) {
pktgen_stop_device(pkt_dev);
return;
}
/* This is max DELAY, this has special meaning of
* "never transmit"
*/
if (unlikely(pkt_dev->delay == ULLONG_MAX)) {
pkt_dev->next_tx = ktime_add_ns(ktime_get(), ULONG_MAX);
return;
}
/* If no skb or clone count exhausted then get new one */
if (!pkt_dev->skb || (pkt_dev->last_ok &&
++pkt_dev->clone_count >= pkt_dev->clone_skb)) {
/* build a new pkt */
kfree_skb(pkt_dev->skb);
pkt_dev->skb = fill_packet(odev, pkt_dev);
if (pkt_dev->skb == NULL) {
pr_err("ERROR: couldn't allocate skb in fill_packet\n");
schedule();
pkt_dev->clone_count--; /* back out increment, OOM */
return;
}
pkt_dev->last_pkt_size = pkt_dev->skb->len;
pkt_dev->allocated_skbs++;
pkt_dev->clone_count = 0; /* reset counter */
}
if (pkt_dev->delay && pkt_dev->last_ok)
spin(pkt_dev, pkt_dev->next_tx);
queue_map = skb_get_queue_mapping(pkt_dev->skb);
txq = netdev_get_tx_queue(odev, queue_map);
local_bh_disable();
HARD_TX_LOCK(odev, txq, smp_processor_id());
if (unlikely(netif_xmit_frozen_or_drv_stopped(txq))) {
ret = NETDEV_TX_BUSY;
pkt_dev->last_ok = 0;
goto unlock;
}
atomic_inc(&(pkt_dev->skb->users));
ret = netdev_start_xmit(pkt_dev->skb, odev);
switch (ret) {
case NETDEV_TX_OK:
txq_trans_update(txq);
pkt_dev->last_ok = 1;
pkt_dev->sofar++;
pkt_dev->seq_num++;
pkt_dev->tx_bytes += pkt_dev->last_pkt_size;
break;
case NET_XMIT_DROP:
case NET_XMIT_CN:
case NET_XMIT_POLICED:
/* skb has been consumed */
pkt_dev->errors++;
break;
default: /* Drivers are not supposed to return other values! */
net_info_ratelimited("%s xmit error: %d\n",
pkt_dev->odevname, ret);
pkt_dev->errors++;
/* fallthru */
case NETDEV_TX_LOCKED:
case NETDEV_TX_BUSY:
/* Retry it next time */
atomic_dec(&(pkt_dev->skb->users));
pkt_dev->last_ok = 0;
}
unlock:
HARD_TX_UNLOCK(odev, txq);
local_bh_enable();
/* If pkt_dev->count is zero, then run forever */
if ((pkt_dev->count != 0) && (pkt_dev->sofar >= pkt_dev->count)) {
pktgen_wait_for_skb(pkt_dev);
/* Done with this */
pktgen_stop_device(pkt_dev);
}
}
/*
* Main loop of the thread goes here
*/
static int pktgen_thread_worker(void *arg)
{
DEFINE_WAIT(wait);
struct pktgen_thread *t = arg;
struct pktgen_dev *pkt_dev = NULL;
int cpu = t->cpu;
BUG_ON(smp_processor_id() != cpu);
init_waitqueue_head(&t->queue);
complete(&t->start_done);
pr_debug("starting pktgen/%d: pid=%d\n", cpu, task_pid_nr(current));
set_freezable();
__set_current_state(TASK_RUNNING);
while (!kthread_should_stop()) {
pkt_dev = next_to_run(t);
if (unlikely(!pkt_dev && t->control == 0)) {
if (t->net->pktgen_exiting)
break;
wait_event_interruptible_timeout(t->queue,
t->control != 0,
HZ/10);
try_to_freeze();
continue;
}
if (likely(pkt_dev)) {
pktgen_xmit(pkt_dev);
if (need_resched())
pktgen_resched(pkt_dev);
else
cpu_relax();
}
if (t->control & T_STOP) {
pktgen_stop(t);
t->control &= ~(T_STOP);
}
if (t->control & T_RUN) {
pktgen_run(t);
t->control &= ~(T_RUN);
}
if (t->control & T_REMDEVALL) {
pktgen_rem_all_ifs(t);
t->control &= ~(T_REMDEVALL);
}
if (t->control & T_REMDEV) {
pktgen_rem_one_if(t);
t->control &= ~(T_REMDEV);
}
try_to_freeze();
}
set_current_state(TASK_INTERRUPTIBLE);
pr_debug("%s stopping all device\n", t->tsk->comm);
pktgen_stop(t);
pr_debug("%s removing all device\n", t->tsk->comm);
pktgen_rem_all_ifs(t);
pr_debug("%s removing thread\n", t->tsk->comm);
pktgen_rem_thread(t);
/* Wait for kthread_stop */
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
schedule();
}
__set_current_state(TASK_RUNNING);
return 0;
}
static struct pktgen_dev *pktgen_find_dev(struct pktgen_thread *t,
const char *ifname, bool exact)
{
struct pktgen_dev *p, *pkt_dev = NULL;
size_t len = strlen(ifname);
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_lock();
list_for_each_entry_rcu(p, &t->if_list, list)
if (strncmp(p->odevname, ifname, len) == 0) {
if (p->odevname[len]) {
if (exact || p->odevname[len] != '@')
continue;
}
pkt_dev = p;
break;
}
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
rcu_read_unlock();
pr_debug("find_dev(%s) returning %p\n", ifname, pkt_dev);
return pkt_dev;
}
/*
* Adds a dev at front of if_list.
*/
static int add_dev_to_thread(struct pktgen_thread *t,
struct pktgen_dev *pkt_dev)
{
int rv = 0;
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
/* This function cannot be called concurrently, as its called
* under pktgen_thread_lock mutex, but it can run from
* userspace on another CPU than the kthread. The if_lock()
* is used here to sync with concurrent instances of
* _rem_dev_from_if_list() invoked via kthread, which is also
* updating the if_list */
if_lock(t);
if (pkt_dev->pg_thread) {
pr_err("ERROR: already assigned to a thread\n");
rv = -EBUSY;
goto out;
}
pkt_dev->running = 0;
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
pkt_dev->pg_thread = t;
list_add_rcu(&pkt_dev->list, &t->if_list);
out:
if_unlock(t);
return rv;
}
/* Called under thread lock */
static int pktgen_add_device(struct pktgen_thread *t, const char *ifname)
{
struct pktgen_dev *pkt_dev;
int err;
int node = cpu_to_node(t->cpu);
/* We don't allow a device to be on several threads */
pkt_dev = __pktgen_NN_threads(t->net, ifname, FIND);
if (pkt_dev) {
pr_err("ERROR: interface already used\n");
return -EBUSY;
}
pkt_dev = kzalloc_node(sizeof(struct pktgen_dev), GFP_KERNEL, node);
if (!pkt_dev)
return -ENOMEM;
pktgen: Fix device name compares Commit e6fce5b916cd7f7f7 (pktgen: multiqueue etc.) tried to relax the pktgen restriction of one device per kernel thread, adding a '@' tag to device names. Problem is we dont perform check on full pktgen device name. This allows adding many time same 'device' to pktgen thread pgset "add_device eth0@0" one session later : pgset "add_device eth0@0" (This doesnt find previous device) This consumes ~1.5 MBytes of vmalloc memory per round and also triggers this warning : [ 673.186380] proc_dir_entry 'pktgen/eth0@0' already registered [ 673.186383] Modules linked in: pktgen ixgbe ehci_hcd psmouse mdio mousedev evdev [last unloaded: pktgen] [ 673.186406] Pid: 6219, comm: bash Tainted: G W 2.6.32-rc7-03302-g41cec6f-dirty #16 [ 673.186410] Call Trace: [ 673.186417] [<ffffffff8104a29b>] warn_slowpath_common+0x7b/0xc0 [ 673.186422] [<ffffffff8104a341>] warn_slowpath_fmt+0x41/0x50 [ 673.186426] [<ffffffff8114e789>] proc_register+0x109/0x210 [ 673.186433] [<ffffffff8100bf2e>] ? apic_timer_interrupt+0xe/0x20 [ 673.186438] [<ffffffff8114e905>] proc_create_data+0x75/0xd0 [ 673.186444] [<ffffffffa006ad38>] pktgen_thread_write+0x568/0x640 [pktgen] [ 673.186449] [<ffffffffa006a7d0>] ? pktgen_thread_write+0x0/0x640 [pktgen] [ 673.186453] [<ffffffff81149144>] proc_reg_write+0x84/0xc0 [ 673.186458] [<ffffffff810f5a58>] vfs_write+0xb8/0x180 [ 673.186463] [<ffffffff810f5c11>] sys_write+0x51/0x90 [ 673.186468] [<ffffffff8100b51b>] system_call_fastpath+0x16/0x1b [ 673.186470] ---[ end trace ccbb991b0a8d994d ]--- Solution to this problem is to use a odevname field (includes @ tag and suffix), instead of using netdevice name. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Robert Olsson <robert.olsson@its.uu.se> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-23 09:44:37 +08:00
strcpy(pkt_dev->odevname, ifname);
pkt_dev->flows = vzalloc_node(MAX_CFLOWS * sizeof(struct flow_state),
node);
if (pkt_dev->flows == NULL) {
kfree(pkt_dev);
return -ENOMEM;
}
pkt_dev->removal_mark = 0;
pkt_dev->nfrags = 0;
pkt_dev->delay = pg_delay_d;
pkt_dev->count = pg_count_d;
pkt_dev->sofar = 0;
pkt_dev->udp_src_min = 9; /* sink port */
pkt_dev->udp_src_max = 9;
pkt_dev->udp_dst_min = 9;
pkt_dev->udp_dst_max = 9;
pkt_dev->vlan_p = 0;
pkt_dev->vlan_cfi = 0;
pkt_dev->vlan_id = 0xffff;
pkt_dev->svlan_p = 0;
pkt_dev->svlan_cfi = 0;
pkt_dev->svlan_id = 0xffff;
pkt_dev->node = -1;
err = pktgen_setup_dev(t->net, pkt_dev, ifname);
if (err)
goto out1;
if (pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)
pkt_dev->clone_skb = pg_clone_skb_d;
pkt_dev->entry = proc_create_data(ifname, 0600, t->net->proc_dir,
&pktgen_if_fops, pkt_dev);
if (!pkt_dev->entry) {
pr_err("cannot create %s/%s procfs entry\n",
PG_PROC_DIR, ifname);
err = -EINVAL;
goto out2;
}
#ifdef CONFIG_XFRM
pkt_dev->ipsmode = XFRM_MODE_TRANSPORT;
pkt_dev->ipsproto = IPPROTO_ESP;
/* xfrm tunnel mode needs additional dst to extract outter
* ip header protocol/ttl/id field, here creat a phony one.
* instead of looking for a valid rt, which definitely hurting
* performance under such circumstance.
*/
pkt_dev->dstops.family = AF_INET;
pkt_dev->dst.dev = pkt_dev->odev;
dst_init_metrics(&pkt_dev->dst, pktgen_dst_metrics, false);
pkt_dev->dst.child = &pkt_dev->dst;
pkt_dev->dst.ops = &pkt_dev->dstops;
#endif
return add_dev_to_thread(t, pkt_dev);
out2:
dev_put(pkt_dev->odev);
out1:
#ifdef CONFIG_XFRM
free_SAs(pkt_dev);
#endif
vfree(pkt_dev->flows);
kfree(pkt_dev);
return err;
}
static int __net_init pktgen_create_thread(int cpu, struct pktgen_net *pn)
{
struct pktgen_thread *t;
struct proc_dir_entry *pe;
struct task_struct *p;
t = kzalloc_node(sizeof(struct pktgen_thread), GFP_KERNEL,
cpu_to_node(cpu));
if (!t) {
pr_err("ERROR: out of memory, can't create new thread\n");
return -ENOMEM;
}
spin_lock_init(&t->if_lock);
t->cpu = cpu;
INIT_LIST_HEAD(&t->if_list);
list_add_tail(&t->th_list, &pn->pktgen_threads);
init_completion(&t->start_done);
p = kthread_create_on_node(pktgen_thread_worker,
t,
cpu_to_node(cpu),
"kpktgend_%d", cpu);
if (IS_ERR(p)) {
pr_err("kernel_thread() failed for cpu %d\n", t->cpu);
list_del(&t->th_list);
kfree(t);
return PTR_ERR(p);
}
kthread_bind(p, cpu);
t->tsk = p;
pe = proc_create_data(t->tsk->comm, 0600, pn->proc_dir,
&pktgen_thread_fops, t);
if (!pe) {
pr_err("cannot create %s/%s procfs entry\n",
PG_PROC_DIR, t->tsk->comm);
kthread_stop(p);
list_del(&t->th_list);
kfree(t);
return -EINVAL;
}
t->net = pn;
wake_up_process(p);
wait_for_completion(&t->start_done);
return 0;
}
/*
* Removes a device from the thread if_list.
*/
static void _rem_dev_from_if_list(struct pktgen_thread *t,
struct pktgen_dev *pkt_dev)
{
struct list_head *q, *n;
struct pktgen_dev *p;
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
if_lock(t);
list_for_each_safe(q, n, &t->if_list) {
p = list_entry(q, struct pktgen_dev, list);
if (p == pkt_dev)
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
list_del_rcu(&p->list);
}
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
if_unlock(t);
}
static int pktgen_remove_device(struct pktgen_thread *t,
struct pktgen_dev *pkt_dev)
{
pr_debug("remove_device pkt_dev=%p\n", pkt_dev);
if (pkt_dev->running) {
pr_warning("WARNING: trying to remove a running interface, stopping it now\n");
pktgen_stop_device(pkt_dev);
}
/* Dis-associate from the interface */
if (pkt_dev->odev) {
dev_put(pkt_dev->odev);
pkt_dev->odev = NULL;
}
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
/* Remove proc before if_list entry, because add_device uses
* list to determine if interface already exist, avoid race
* with proc_create_data() */
if (pkt_dev->entry)
proc_remove(pkt_dev->entry);
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
/* And update the thread if_list */
_rem_dev_from_if_list(t, pkt_dev);
#ifdef CONFIG_XFRM
free_SAs(pkt_dev);
#endif
vfree(pkt_dev->flows);
if (pkt_dev->page)
put_page(pkt_dev->page);
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
kfree_rcu(pkt_dev, rcu);
return 0;
}
static int __net_init pg_net_init(struct net *net)
{
struct pktgen_net *pn = net_generic(net, pg_net_id);
struct proc_dir_entry *pe;
int cpu, ret = 0;
pn->net = net;
INIT_LIST_HEAD(&pn->pktgen_threads);
pn->pktgen_exiting = false;
pn->proc_dir = proc_mkdir(PG_PROC_DIR, pn->net->proc_net);
if (!pn->proc_dir) {
pr_warn("cannot create /proc/net/%s\n", PG_PROC_DIR);
return -ENODEV;
}
pe = proc_create(PGCTRL, 0600, pn->proc_dir, &pktgen_fops);
if (pe == NULL) {
pr_err("cannot create %s procfs entry\n", PGCTRL);
ret = -EINVAL;
goto remove;
}
for_each_online_cpu(cpu) {
int err;
err = pktgen_create_thread(cpu, pn);
if (err)
pr_warn("Cannot create thread for cpu %d (%d)\n",
cpu, err);
}
if (list_empty(&pn->pktgen_threads)) {
pr_err("Initialization failed for all threads\n");
ret = -ENODEV;
goto remove_entry;
}
return 0;
remove_entry:
remove_proc_entry(PGCTRL, pn->proc_dir);
remove:
remove_proc_entry(PG_PROC_DIR, pn->net->proc_net);
return ret;
}
static void __net_exit pg_net_exit(struct net *net)
{
struct pktgen_net *pn = net_generic(net, pg_net_id);
struct pktgen_thread *t;
struct list_head *q, *n;
LIST_HEAD(list);
/* Stop all interfaces & threads */
pn->pktgen_exiting = true;
mutex_lock(&pktgen_thread_lock);
list_splice_init(&pn->pktgen_threads, &list);
mutex_unlock(&pktgen_thread_lock);
list_for_each_safe(q, n, &list) {
t = list_entry(q, struct pktgen_thread, th_list);
list_del(&t->th_list);
kthread_stop(t->tsk);
kfree(t);
}
remove_proc_entry(PGCTRL, pn->proc_dir);
remove_proc_entry(PG_PROC_DIR, pn->net->proc_net);
}
static struct pernet_operations pg_net_ops = {
.init = pg_net_init,
.exit = pg_net_exit,
.id = &pg_net_id,
.size = sizeof(struct pktgen_net),
};
static int __init pg_init(void)
{
int ret = 0;
pr_info("%s", version);
ret = register_pernet_subsys(&pg_net_ops);
if (ret)
return ret;
ret = register_netdevice_notifier(&pktgen_notifier_block);
if (ret)
unregister_pernet_subsys(&pg_net_ops);
return ret;
}
static void __exit pg_cleanup(void)
{
unregister_netdevice_notifier(&pktgen_notifier_block);
unregister_pernet_subsys(&pg_net_ops);
pktgen: RCU-ify "if_list" to remove lock in next_to_run() The if_lock()/if_unlock() in next_to_run() adds a significant overhead, because its called for every packet in busy loop of pktgen_thread_worker(). (Thomas Graf originally pointed me at this lock problem). Removing these two "LOCK" operations should in theory save us approx 16ns (8ns x 2), as illustrated below we do save 16ns when removing the locks and introducing RCU protection. Performance data with CLONE_SKB==100000, TX-size=512, rx-usecs=30: (single CPU performance, ixgbe 10Gbit/s, E5-2630) * Prev : 5684009 pps --> 175.93ns (1/5684009*10^9) * RCU-fix: 6272204 pps --> 159.43ns (1/6272204*10^9) * Diff : +588195 pps --> -16.50ns To understand this RCU patch, I describe the pktgen thread model below. In pktgen there is several kernel threads, but there is only one CPU running each kernel thread. Communication with the kernel threads are done through some thread control flags. This allow the thread to change data structures at a know synchronization point, see main thread func pktgen_thread_worker(). Userspace changes are communicated through proc-file writes. There are three types of changes, general control changes "pgctrl" (func:pgctrl_write), thread changes "kpktgend_X" (func:pktgen_thread_write), and interface config changes "etcX@N" (func:pktgen_if_write). Userspace "pgctrl" and "thread" changes are synchronized via the mutex pktgen_thread_lock, thus only a single userspace instance can run. The mutex is taken while the packet generator is running, by pgctrl "start". Thus e.g. "add_device" cannot be invoked when pktgen is running/started. All "pgctrl" and all "thread" changes, except thread "add_device", communicate via the thread control flags. The main problem is the exception "add_device", that modifies threads "if_list" directly. Fortunately "add_device" cannot be invoked while pktgen is running. But there exists a race between "rem_device_all" and "add_device" (which normally don't occur, because "rem_device_all" waits 125ms before returning). Background'ing "rem_device_all" and running "add_device" immediately allow the race to occur. The race affects the threads (list of devices) "if_list". The if_lock is used for protecting this "if_list". Other readers are given lock-free access to the list under RCU read sections. Note, interface config changes (via proc) can occur while pktgen is running, which worries me a bit. I'm assuming proc_remove() takes appropriate locks, to assure no writers exists after proc_remove() finish. I've been running a script exercising the race condition (leading me to fix the proc_remove order), without any issues. The script also exercises concurrent proc writes, while the interface config is getting removed. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-26 19:16:59 +08:00
/* Don't need rcu_barrier() due to use of kfree_rcu() */
}
module_init(pg_init);
module_exit(pg_cleanup);
MODULE_AUTHOR("Robert Olsson <robert.olsson@its.uu.se>");
MODULE_DESCRIPTION("Packet Generator tool");
MODULE_LICENSE("GPL");
MODULE_VERSION(VERSION);
module_param(pg_count_d, int, 0);
MODULE_PARM_DESC(pg_count_d, "Default number of packets to inject");
module_param(pg_delay_d, int, 0);
MODULE_PARM_DESC(pg_delay_d, "Default delay between packets (nanoseconds)");
module_param(pg_clone_skb_d, int, 0);
MODULE_PARM_DESC(pg_clone_skb_d, "Default number of copies of the same packet");
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Enable debugging of pktgen module");