Eric Dumazet 3bcb846ca4 net: get rid of spin_trylock() in net_tx_action() ... Note: Tom Herbert posted almost same patch 3 months back, but for different reasons. The reasons we want to get rid of this spin_trylock() are : 1) Under high qdisc pressure, the spin_trylock() has almost no chance to succeed. 2) We loop multiple times in softirq handler, eventually reaching the max retry count (10), and we schedule ksoftirqd. Since we want to adhere more strictly to ksoftirqd being waked up in the future (https://lwn.net/Articles/687617/), better avoid spurious wakeups. 3) calls to __netif_reschedule() dirty the cache line containing q->next_sched, slowing down the owner of qdisc. 4) RT kernels can not use the spin_trylock() here. With help of busylock, we get the qdisc spinlock fast enough, and the trylock trick brings only performance penalty. Depending on qdisc setup, I observed a gain of up to 19 % in qdisc performance (1016600 pps instead of 853400 pps, using prio+tbf+fq_codel) ("mpstat -I SCPU 1" is much happier now) Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <tom@herbertland.com> Acked-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2016-06-07 15:32:03 -07:00
..
6lowpan	6lowpan: move mac802154 header	2016-04-13 10:41:10 +02:00
9p	remove lots of IS_ERR_VALUE abuses	2016-05-27 15:26:11 -07:00
802	…
8021q	vlan: Propagate MAC address to VLANs	2016-05-31 11:56:48 -07:00
appletalk	appletalk: fix erroneous return value	2016-02-18 14:59:34 -05:00
atm	net/atm: sk_err_soft must be positive	2016-05-23 13:51:10 -07:00
ax25	ax25: add link layer header validation function	2016-03-09 22:13:01 -05:00
batman-adv	batman-adv: initialize ELP orig address on secondary interfaces	2016-05-18 11:49:44 +08:00
bluetooth	Bluetooth: fix power_on vs close race	2016-05-13 16:50:23 +02:00
bridge	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2016-05-09 15:59:24 -04:00
caif	net: caif: fix misleading indentation	2016-03-14 13:09:50 -04:00
can	sock: enable timestamping using control messages	2016-04-04 15:50:30 -04:00
ceph	libceph: make ceph_osdc_wait_request() uninterruptible	2016-05-26 01:15:40 +02:00
core	net: get rid of spin_trylock() in net_tx_action()	2016-06-07 15:32:03 -07:00
dcb	…
dccp	dccp: do not assume DCCP code is non preemptible	2016-05-02 17:02:25 -04:00
decnet	decnet: Do not build routes to devices without decnet private data.	2016-04-10 23:01:30 -04:00
dns_resolver	KEYS: Add a facility to restrict new links into a keyring	2016-04-11 22:37:37 +01:00
dsa	net: dsa: Add new binding implementation	2016-06-04 14:29:55 -07:00
ethernet	eth: Pull header from first fragment via eth_get_headlen	2016-02-24 13:58:05 -05:00
hsr	net/hsr: Use setup_timer and mod_timer.	2016-05-16 14:00:43 -04:00
ieee802154	ieee802154: fix logic error in ieee802154_llsec_parse_dev_addr	2016-05-29 22:36:25 -07:00
ipv4	net: disable fragment reassembly if high_thresh is zero	2016-06-05 22:56:42 -04:00
ipv6	skbuff: introduce skb_gso_validate_mtu	2016-06-03 19:37:21 -04:00
ipx	…
irda	TTY and Serial driver update for 4.7-rc1	2016-05-20 20:57:27 -07:00
iucv	af_iucv: Validate socket address length in iucv_sock_bind()	2016-01-19 14:21:08 -05:00
kcm	kcm: fix a signedness in kcm_splice_read()	2016-05-19 11:26:51 -07:00
key	af_key: fix two typos	2015-10-23 03:05:19 -07:00
l2tp	net: l2tp: Make l2tp_ip6 namespace aware	2016-05-30 00:03:53 -07:00
l3mdev	net: l3mdev: Allow send on enslaved interface	2016-05-09 22:33:52 -04:00
lapb	net/lapb: tuse %*ph to dump buffers	2016-05-29 22:33:25 -07:00
llc	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2016-05-09 15:59:24 -04:00
mac80211	Some more work for 4.7, notably:	2016-05-12 11:46:58 -04:00
mac802154	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2016-03-19 10:05:34 -07:00
mpls	skbuff: introduce skb_gso_validate_mtu	2016-06-03 19:37:21 -04:00
netfilter	net: define gso types for IPx over IPv4 and IPv6	2016-05-20 18:03:15 -04:00
netlabel	netlabel: fix a problem with netlbl_secattr_catmap_setrng()	2016-04-05 16:10:47 -04:00
netlink	netlink: Fix dump skb leak/double free	2016-05-16 22:05:15 -04:00
netrom	…
nfc	nfc: nci: Add nci_nfcc_loopback to the nci core	2016-05-04 01:48:16 +02:00
openvswitch	ovs: set name assign type of internal port	2016-06-02 18:05:47 -04:00
packet	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2016-04-23 18:51:33 -04:00
phonet	sock: struct proto hash function may error	2016-02-11 03:54:14 -05:00
qrtr	Merge tag 'qcom-soc-for-4.7-2' into net-next	2016-05-17 14:11:19 -04:00
rds	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2016-05-20 20:01:26 -07:00
rfkill	rfkill: Use switch to demux userspace operations	2016-04-05 10:48:53 +02:00
rose	…
rxrpc	rxrpc: Use pr_<level> and pr_fmt, reduce object size a few KB	2016-06-03 19:41:31 -04:00
sched	net sched actions: policer missing timestamp processing	2016-05-24 16:23:23 -07:00
sctp	sctp: Fix warning in sctp_packet_transmit_chunk()	2016-06-03 22:53:26 -07:00
sunrpc	NFS client updates for Linux 4.7	2016-05-26 10:33:33 -07:00
switchdev	switchdev: pass pointer to fib_info instead of copy	2016-05-17 13:58:49 -04:00
tipc	tipc: fix potential null pointer dereferences in some compat functions	2016-05-25 12:33:52 -07:00
unix	constify security_path_{mkdir,mknod,symlink}	2016-03-28 00:47:27 -04:00
vmw_vsock	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2016-05-09 15:59:24 -04:00
wimax	…
wireless	mm/page_ref: use page_ref helper instead of direct modification of _count	2016-05-19 19:12:14 -07:00
x25	net: fix a kernel infoleak in x25 module	2016-05-09 22:45:33 -04:00
xfrm	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2016-05-09 15:59:24 -04:00
Kconfig	bpf: add generic constant blinding for use in jits	2016-05-16 13:49:32 -04:00
Makefile	net: Add Qualcomm IPC router	2016-05-08 23:46:14 -04:00
compat.c	…
socket.c	fs: poll/select/recvmmsg: use timespec64 for timeout events	2016-05-19 19:12:14 -07:00
sysctl_net.c	net: sysctl: fix a kmemleak warning	2015-10-23 06:22:08 -07:00