OpenCloudOS-Kernel/include/linux/smp.h

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_SMP_H
#define __LINUX_SMP_H
/*
* Generic SMP support
* Alan Cox. <alan@redhat.com>
*/
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/llist.h>
typedef void (*smp_call_func_t)(void *info);
typedef bool (*smp_cond_func_t)(int cpu, void *info);
enum {
CSD_FLAG_LOCK = 0x01,
/* IRQ_WORK_flags */
CSD_TYPE_ASYNC = 0x00,
CSD_TYPE_SYNC = 0x10,
CSD_TYPE_IRQ_WORK = 0x20,
CSD_TYPE_TTWU = 0x30,
CSD_FLAG_TYPE_MASK = 0xF0,
};
/*
* structure shares (partial) layout with struct irq_work
*/
smp: Avoid using two cache lines for struct call_single_data struct call_single_data is used in IPIs to transfer information between CPUs. Its size is bigger than sizeof(unsigned long) and less than cache line size. Currently it is not allocated with any explicit alignment requirements. This makes it possible for allocated call_single_data to cross two cache lines, which results in double the number of the cache lines that need to be transferred among CPUs. This can be fixed by requiring call_single_data to be aligned with the size of call_single_data. Currently the size of call_single_data is the power of 2. If we add new fields to call_single_data, we may need to add padding to make sure the size of new definition is the power of 2 as well. Fortunately, this is enforced by GCC, which will report bad sizes. To set alignment requirements of call_single_data to the size of call_single_data, a struct definition and a typedef is used. To test the effect of the patch, I used the vm-scalability multiple thread swap test case (swap-w-seq-mt). The test will create multiple threads and each thread will eat memory until all RAM and part of swap is used, so that huge number of IPIs are triggered when unmapping memory. In the test, the throughput of memory writing improves ~5% compared with misaligned call_single_data, because of faster IPIs. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Huang, Ying <ying.huang@intel.com> [ Add call_single_data_t and align with size of call_single_data. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/87bmnqd6lz.fsf@yhuang-mobile.sh.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-08 12:30:00 +08:00
struct __call_single_data {
struct llist_node llist;
unsigned int flags;
smp_call_func_t func;
void *info;
};
smp: Avoid using two cache lines for struct call_single_data struct call_single_data is used in IPIs to transfer information between CPUs. Its size is bigger than sizeof(unsigned long) and less than cache line size. Currently it is not allocated with any explicit alignment requirements. This makes it possible for allocated call_single_data to cross two cache lines, which results in double the number of the cache lines that need to be transferred among CPUs. This can be fixed by requiring call_single_data to be aligned with the size of call_single_data. Currently the size of call_single_data is the power of 2. If we add new fields to call_single_data, we may need to add padding to make sure the size of new definition is the power of 2 as well. Fortunately, this is enforced by GCC, which will report bad sizes. To set alignment requirements of call_single_data to the size of call_single_data, a struct definition and a typedef is used. To test the effect of the patch, I used the vm-scalability multiple thread swap test case (swap-w-seq-mt). The test will create multiple threads and each thread will eat memory until all RAM and part of swap is used, so that huge number of IPIs are triggered when unmapping memory. In the test, the throughput of memory writing improves ~5% compared with misaligned call_single_data, because of faster IPIs. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Huang, Ying <ying.huang@intel.com> [ Add call_single_data_t and align with size of call_single_data. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/87bmnqd6lz.fsf@yhuang-mobile.sh.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-08 12:30:00 +08:00
/* Use __aligned() to avoid to use 2 cache lines for 1 csd */
typedef struct __call_single_data call_single_data_t
__aligned(sizeof(struct __call_single_data));
/*
* Enqueue a llist_node on the call_single_queue; be very careful, read
* flush_smp_call_function_queue() in detail.
*/
extern void __smp_call_single_queue(int cpu, struct llist_node *node);
cpumask: add sysfs displays for configured and disabled cpu maps Impact: add new sysfs files. Add sysfs files "kernel_max" and "offline" to display the max CPU index allowed (NR_CPUS-1), and the map of cpus that are offline. Cpus can be offlined via HOTPLUG, disabled by the BIOS ACPI tables, or if they exceed the number of cpus allowed by the NR_CPUS config option, or the "maxcpus=NUM" kernel start parameter. The "possible_cpus=NUM" parameter can also extend the number of possible cpus allowed, in which case the cpus not present at startup will be in the offline state. (These cpus can be HOTPLUGGED ON after system startup [pending a follow-on patch to provide the capability via the /sys/devices/sys/cpu/cpuN/online mechanism to bring them online.]) By design, the "offlined cpus > possible cpus" display will always use the following formats: * all possible cpus online: "x$" or "x-y$" * some possible cpus offline: ".*,x$" or ".*,x-y$" where: x == number of possible cpus (nr_cpu_ids); and y == number of cpus >= NR_CPUS or maxcpus (if y > x). One use of this feature is for distros to select (or configure) the appropriate kernel to install for the resident system. Notes: * cpus offlined <= possible cpus will be printed for all architectures. * cpus offlined > possible cpus will only be printed for arches that set 'total_cpus' [X86 only in this patch]. Based on tip/cpus4096 + .../rusty/linux-2.6-for-ingo.git/master + x86-only-patches sent 12/15. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-16 12:26:48 +08:00
/* total number of cpus in this system (may exceed NR_CPUS) */
extern unsigned int total_cpus;
int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
int wait);
/*
* Call a function on all processors
*/
void on_each_cpu(smp_call_func_t func, void *info, int wait);
/*
* Call a function on processors specified by mask, which might include
* the local one.
*/
void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
void *info, bool wait);
/*
* Call a function on each processor for which the supplied function
* cond_func returns a positive value. This may include the local
* processor.
*/
void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func,
void *info, bool wait);
void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
void *info, bool wait, const struct cpumask *mask);
smp: Avoid using two cache lines for struct call_single_data struct call_single_data is used in IPIs to transfer information between CPUs. Its size is bigger than sizeof(unsigned long) and less than cache line size. Currently it is not allocated with any explicit alignment requirements. This makes it possible for allocated call_single_data to cross two cache lines, which results in double the number of the cache lines that need to be transferred among CPUs. This can be fixed by requiring call_single_data to be aligned with the size of call_single_data. Currently the size of call_single_data is the power of 2. If we add new fields to call_single_data, we may need to add padding to make sure the size of new definition is the power of 2 as well. Fortunately, this is enforced by GCC, which will report bad sizes. To set alignment requirements of call_single_data to the size of call_single_data, a struct definition and a typedef is used. To test the effect of the patch, I used the vm-scalability multiple thread swap test case (swap-w-seq-mt). The test will create multiple threads and each thread will eat memory until all RAM and part of swap is used, so that huge number of IPIs are triggered when unmapping memory. In the test, the throughput of memory writing improves ~5% compared with misaligned call_single_data, because of faster IPIs. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Huang, Ying <ying.huang@intel.com> [ Add call_single_data_t and align with size of call_single_data. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/87bmnqd6lz.fsf@yhuang-mobile.sh.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-08 12:30:00 +08:00
int smp_call_function_single_async(int cpu, call_single_data_t *csd);
#ifdef CONFIG_SMP
#include <linux/preempt.h>
#include <linux/kernel.h>
#include <linux/compiler.h>
#include <linux/thread_info.h>
#include <asm/smp.h>
/*
* main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
* (defined in asm header):
*/
/*
* stops all CPUs but the current one:
*/
extern void smp_send_stop(void);
/*
* sends a 'reschedule' event to another CPU:
*/
extern void smp_send_reschedule(int cpu);
/*
* Prepare machine for booting other CPUs.
*/
extern void smp_prepare_cpus(unsigned int max_cpus);
/*
* Bring a CPU up
*/
extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
/*
* Final polishing of CPUs
*/
extern void smp_cpus_done(unsigned int max_cpus);
/*
* Call a function on all other processors
*/
void smp_call_function(smp_call_func_t func, void *info, int wait);
void smp_call_function_many(const struct cpumask *mask,
smp_call_func_t func, void *info, bool wait);
int smp_call_function_any(const struct cpumask *mask,
smp_call_func_t func, void *info, int wait);
void kick_all_cpus_sync(void);
void wake_up_all_idle_cpus(void);
/*
* Generic and arch helpers
*/
generic-ipi: Fix kexec boot crash by initializing call_single_queue before enabling interrupts There is a problem that kdump(2nd kernel) sometimes hangs up due to a pending IPI from 1st kernel. Kernel panic occurs because IPI comes before call_single_queue is initialized. To fix the crash, rename init_call_single_data() to call_function_init() and call it in start_kernel() so that call_single_queue can be initialized before enabling interrupts. The details of the crash are: (1) 2nd kernel boots up (2) A pending IPI from 1st kernel comes when irqs are first enabled in start_kernel(). (3) Kernel tries to handle the interrupt, but call_single_queue is not initialized yet at this point. As a result, in the generic_smp_call_function_single_interrupt(), NULL pointer dereference occurs when list_replace_init() tries to access &q->list.next. Therefore this patch changes the name of init_call_single_data() to call_function_init() and calls it before local_irq_enable() in start_kernel(). Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Milton Miller <miltonm@bga.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: kexec@lists.infradead.org Link: http://lkml.kernel.org/r/D6CBEE2F420741indou.takao@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-30 00:35:04 +08:00
void __init call_function_init(void);
void generic_smp_call_function_single_interrupt(void);
smp: make smp_call_function_many() use logic similar to smp_call_function_single() I'm testing swapout workload in a two-socket Xeon machine. The workload has 10 threads, each thread sequentially accesses separate memory region. TLB flush overhead is very big in the workload. For each page, page reclaim need move it from active lru list and then unmap it. Both need a TLB flush. And this is a multthread workload, TLB flush happens in 10 CPUs. In X86, TLB flush uses generic smp_call)function. So this workload stress smp_call_function_many heavily. Without patch, perf shows: + 24.49% [k] generic_smp_call_function_interrupt - 21.72% [k] _raw_spin_lock - _raw_spin_lock + 79.80% __page_check_address + 6.42% generic_smp_call_function_interrupt + 3.31% get_swap_page + 2.37% free_pcppages_bulk + 1.75% handle_pte_fault + 1.54% put_super + 1.41% grab_super_passive + 1.36% __swap_duplicate + 0.68% blk_flush_plug_list + 0.62% swap_info_get + 6.55% [k] flush_tlb_func + 6.46% [k] smp_call_function_many + 5.09% [k] call_function_interrupt + 4.75% [k] default_send_IPI_mask_sequence_phys + 2.18% [k] find_next_bit swapout throughput is around 1300M/s. With the patch, perf shows: - 27.23% [k] _raw_spin_lock - _raw_spin_lock + 80.53% __page_check_address + 8.39% generic_smp_call_function_single_interrupt + 2.44% get_swap_page + 1.76% free_pcppages_bulk + 1.40% handle_pte_fault + 1.15% __swap_duplicate + 1.05% put_super + 0.98% grab_super_passive + 0.86% blk_flush_plug_list + 0.57% swap_info_get + 8.25% [k] default_send_IPI_mask_sequence_phys + 7.55% [k] call_function_interrupt + 7.47% [k] smp_call_function_many + 7.25% [k] flush_tlb_func + 3.81% [k] _raw_spin_lock_irqsave + 3.78% [k] generic_smp_call_function_single_interrupt swapout throughput is around 1400M/s. So there is around a 7% improvement, and total cpu utilization doesn't change. Without the patch, cfd_data is shared by all CPUs. generic_smp_call_function_interrupt does read/write cfd_data several times which will create a lot of cache ping-pong. With the patch, the data becomes per-cpu. The ping-pong is avoided. And from the perf data, this doesn't make call_single_queue lock contend. Next step is to remove generic_smp_call_function_interrupt() from arch code. Signed-off-by: Shaohua Li <shli@fusionio.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-22 08:43:03 +08:00
#define generic_smp_call_function_interrupt \
generic_smp_call_function_single_interrupt
/*
* Mark the boot cpu "online" so that it can call console drivers in
* printk() and can access its per-cpu storage.
*/
void smp_prepare_boot_cpu(void);
extern unsigned int setup_max_cpus;
extern void __init setup_nr_cpu_ids(void);
extern void __init smp_init(void);
extern int __boot_cpu_id;
static inline int get_boot_cpu_id(void)
{
return __boot_cpu_id;
}
#else /* !SMP */
static inline void smp_send_stop(void) { }
/*
* These macros fold the SMP functionality into a single CPU system
*/
#define raw_smp_processor_id() 0
static inline void up_smp_call_function(smp_call_func_t func, void *info)
{
}
#define smp_call_function(func, info, wait) \
(up_smp_call_function(func, info))
static inline void smp_send_reschedule(int cpu) { }
#define smp_prepare_boot_cpu() do {} while (0)
#define smp_call_function_many(mask, func, info, wait) \
(up_smp_call_function(func, info))
generic-ipi: Fix kexec boot crash by initializing call_single_queue before enabling interrupts There is a problem that kdump(2nd kernel) sometimes hangs up due to a pending IPI from 1st kernel. Kernel panic occurs because IPI comes before call_single_queue is initialized. To fix the crash, rename init_call_single_data() to call_function_init() and call it in start_kernel() so that call_single_queue can be initialized before enabling interrupts. The details of the crash are: (1) 2nd kernel boots up (2) A pending IPI from 1st kernel comes when irqs are first enabled in start_kernel(). (3) Kernel tries to handle the interrupt, but call_single_queue is not initialized yet at this point. As a result, in the generic_smp_call_function_single_interrupt(), NULL pointer dereference occurs when list_replace_init() tries to access &q->list.next. Therefore this patch changes the name of init_call_single_data() to call_function_init() and calls it before local_irq_enable() in start_kernel(). Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Milton Miller <miltonm@bga.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: kexec@lists.infradead.org Link: http://lkml.kernel.org/r/D6CBEE2F420741indou.takao@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-30 00:35:04 +08:00
static inline void call_function_init(void) { }
static inline int
smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
void *info, int wait)
{
return smp_call_function_single(0, func, info, wait);
}
static inline void kick_all_cpus_sync(void) { }
static inline void wake_up_all_idle_cpus(void) { }
#ifdef CONFIG_UP_LATE_INIT
extern void __init up_late_init(void);
static inline void smp_init(void) { up_late_init(); }
#else
static inline void smp_init(void) { }
#endif
static inline int get_boot_cpu_id(void)
{
return 0;
}
#endif /* !SMP */
x86/percpu: Relax smp_processor_id() Nadav reported that since this_cpu_read() became asm-volatile, many smp_processor_id() users generated worse code due to the extra constraints. However since smp_processor_id() is reading a stable value, we can use __this_cpu_read(). While this does reduce text size somewhat, this mostly results in code movement to .text.unlikely as a result of more/larger .cold. subfunctions. Less text on the hotpath is good for I$. $ ./compare.sh defconfig-build1 defconfig-build2 vmlinux.o setup_APIC_ibs 90 98 -12,+20 force_ibs_eilvt_setup 400 413 -57,+70 pci_serr_error 109 104 -54,+49 pci_serr_error 109 104 -54,+49 unknown_nmi_error 125 120 -76,+71 unknown_nmi_error 125 120 -76,+71 io_check_error 125 132 -97,+104 intel_thermal_interrupt 730 822 +92,+0 intel_init_thermal 951 945 -6,+0 generic_get_mtrr 301 294 -7,+0 generic_get_mtrr 301 294 -7,+0 generic_set_all 749 754 -44,+49 get_fixed_ranges 352 360 -41,+49 x86_acpi_suspend_lowlevel 369 363 -6,+0 check_tsc_sync_source 412 412 -71,+71 irq_migrate_all_off_this_cpu 662 674 -14,+26 clocksource_watchdog 748 748 -113,+113 __perf_event_account_interrupt 204 197 -7,+0 attempt_merge 1748 1741 -7,+0 intel_guc_send_ct 1424 1409 -15,+0 __fini_doorbell 235 231 -4,+0 bdw_set_cdclk 928 923 -5,+0 gen11_dsi_disable 1571 1556 -15,+0 gmbus_wait 493 488 -5,+0 md_make_request 376 369 -7,+0 __split_and_process_bio 543 536 -7,+0 delay_tsc 96 89 -7,+0 hsw_disable_pc8 696 691 -5,+0 tsc_verify_tsc_adjust 215 228 -22,+35 cpuidle_driver_unref 56 49 -7,+0 blk_account_io_completion 159 148 -11,+0 mtrr_wrmsr 95 99 -29,+33 __intel_wait_for_register_fw 401 419 +18,+0 cpuidle_driver_ref 43 36 -7,+0 cpuidle_get_driver 15 8 -7,+0 blk_account_io_done 535 528 -7,+0 irq_migrate_all_off_this_cpu 662 674 -14,+26 check_tsc_sync_source 412 412 -71,+71 irq_wait_for_poll 170 163 -7,+0 generic_end_io_acct 329 322 -7,+0 x86_acpi_suspend_lowlevel 369 363 -6,+0 nohz_balance_enter_idle 198 191 -7,+0 generic_start_io_acct 254 247 -7,+0 blk_account_io_start 341 334 -7,+0 perf_event_task_tick 682 675 -7,+0 intel_init_thermal 951 945 -6,+0 amd_e400_c1e_apic_setup 47 51 -28,+32 setup_APIC_eilvt 350 328 -22,+0 hsw_enable_pc8 1611 1605 -6,+0 total 12985947 12985892 -994,+939 Reported-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-27 16:48:51 +08:00
/**
* raw_processor_id() - get the current (unstable) CPU id
*
* For then you know what you are doing and need an unstable
* CPU id.
*/
/**
* smp_processor_id() - get the current (stable) CPU id
*
* This is the normal accessor to the CPU id and should be used
* whenever possible.
*
* The CPU id is stable when:
*
x86/percpu: Relax smp_processor_id() Nadav reported that since this_cpu_read() became asm-volatile, many smp_processor_id() users generated worse code due to the extra constraints. However since smp_processor_id() is reading a stable value, we can use __this_cpu_read(). While this does reduce text size somewhat, this mostly results in code movement to .text.unlikely as a result of more/larger .cold. subfunctions. Less text on the hotpath is good for I$. $ ./compare.sh defconfig-build1 defconfig-build2 vmlinux.o setup_APIC_ibs 90 98 -12,+20 force_ibs_eilvt_setup 400 413 -57,+70 pci_serr_error 109 104 -54,+49 pci_serr_error 109 104 -54,+49 unknown_nmi_error 125 120 -76,+71 unknown_nmi_error 125 120 -76,+71 io_check_error 125 132 -97,+104 intel_thermal_interrupt 730 822 +92,+0 intel_init_thermal 951 945 -6,+0 generic_get_mtrr 301 294 -7,+0 generic_get_mtrr 301 294 -7,+0 generic_set_all 749 754 -44,+49 get_fixed_ranges 352 360 -41,+49 x86_acpi_suspend_lowlevel 369 363 -6,+0 check_tsc_sync_source 412 412 -71,+71 irq_migrate_all_off_this_cpu 662 674 -14,+26 clocksource_watchdog 748 748 -113,+113 __perf_event_account_interrupt 204 197 -7,+0 attempt_merge 1748 1741 -7,+0 intel_guc_send_ct 1424 1409 -15,+0 __fini_doorbell 235 231 -4,+0 bdw_set_cdclk 928 923 -5,+0 gen11_dsi_disable 1571 1556 -15,+0 gmbus_wait 493 488 -5,+0 md_make_request 376 369 -7,+0 __split_and_process_bio 543 536 -7,+0 delay_tsc 96 89 -7,+0 hsw_disable_pc8 696 691 -5,+0 tsc_verify_tsc_adjust 215 228 -22,+35 cpuidle_driver_unref 56 49 -7,+0 blk_account_io_completion 159 148 -11,+0 mtrr_wrmsr 95 99 -29,+33 __intel_wait_for_register_fw 401 419 +18,+0 cpuidle_driver_ref 43 36 -7,+0 cpuidle_get_driver 15 8 -7,+0 blk_account_io_done 535 528 -7,+0 irq_migrate_all_off_this_cpu 662 674 -14,+26 check_tsc_sync_source 412 412 -71,+71 irq_wait_for_poll 170 163 -7,+0 generic_end_io_acct 329 322 -7,+0 x86_acpi_suspend_lowlevel 369 363 -6,+0 nohz_balance_enter_idle 198 191 -7,+0 generic_start_io_acct 254 247 -7,+0 blk_account_io_start 341 334 -7,+0 perf_event_task_tick 682 675 -7,+0 intel_init_thermal 951 945 -6,+0 amd_e400_c1e_apic_setup 47 51 -28,+32 setup_APIC_eilvt 350 328 -22,+0 hsw_enable_pc8 1611 1605 -6,+0 total 12985947 12985892 -994,+939 Reported-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-27 16:48:51 +08:00
* - IRQs are disabled;
* - preemption is disabled;
* - the task is CPU affine.
*
x86/percpu: Relax smp_processor_id() Nadav reported that since this_cpu_read() became asm-volatile, many smp_processor_id() users generated worse code due to the extra constraints. However since smp_processor_id() is reading a stable value, we can use __this_cpu_read(). While this does reduce text size somewhat, this mostly results in code movement to .text.unlikely as a result of more/larger .cold. subfunctions. Less text on the hotpath is good for I$. $ ./compare.sh defconfig-build1 defconfig-build2 vmlinux.o setup_APIC_ibs 90 98 -12,+20 force_ibs_eilvt_setup 400 413 -57,+70 pci_serr_error 109 104 -54,+49 pci_serr_error 109 104 -54,+49 unknown_nmi_error 125 120 -76,+71 unknown_nmi_error 125 120 -76,+71 io_check_error 125 132 -97,+104 intel_thermal_interrupt 730 822 +92,+0 intel_init_thermal 951 945 -6,+0 generic_get_mtrr 301 294 -7,+0 generic_get_mtrr 301 294 -7,+0 generic_set_all 749 754 -44,+49 get_fixed_ranges 352 360 -41,+49 x86_acpi_suspend_lowlevel 369 363 -6,+0 check_tsc_sync_source 412 412 -71,+71 irq_migrate_all_off_this_cpu 662 674 -14,+26 clocksource_watchdog 748 748 -113,+113 __perf_event_account_interrupt 204 197 -7,+0 attempt_merge 1748 1741 -7,+0 intel_guc_send_ct 1424 1409 -15,+0 __fini_doorbell 235 231 -4,+0 bdw_set_cdclk 928 923 -5,+0 gen11_dsi_disable 1571 1556 -15,+0 gmbus_wait 493 488 -5,+0 md_make_request 376 369 -7,+0 __split_and_process_bio 543 536 -7,+0 delay_tsc 96 89 -7,+0 hsw_disable_pc8 696 691 -5,+0 tsc_verify_tsc_adjust 215 228 -22,+35 cpuidle_driver_unref 56 49 -7,+0 blk_account_io_completion 159 148 -11,+0 mtrr_wrmsr 95 99 -29,+33 __intel_wait_for_register_fw 401 419 +18,+0 cpuidle_driver_ref 43 36 -7,+0 cpuidle_get_driver 15 8 -7,+0 blk_account_io_done 535 528 -7,+0 irq_migrate_all_off_this_cpu 662 674 -14,+26 check_tsc_sync_source 412 412 -71,+71 irq_wait_for_poll 170 163 -7,+0 generic_end_io_acct 329 322 -7,+0 x86_acpi_suspend_lowlevel 369 363 -6,+0 nohz_balance_enter_idle 198 191 -7,+0 generic_start_io_acct 254 247 -7,+0 blk_account_io_start 341 334 -7,+0 perf_event_task_tick 682 675 -7,+0 intel_init_thermal 951 945 -6,+0 amd_e400_c1e_apic_setup 47 51 -28,+32 setup_APIC_eilvt 350 328 -22,+0 hsw_enable_pc8 1611 1605 -6,+0 total 12985947 12985892 -994,+939 Reported-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-27 16:48:51 +08:00
* When CONFIG_DEBUG_PREEMPT; we verify these assumption and WARN
* when smp_processor_id() is used when the CPU id is not stable.
*/
x86/percpu: Relax smp_processor_id() Nadav reported that since this_cpu_read() became asm-volatile, many smp_processor_id() users generated worse code due to the extra constraints. However since smp_processor_id() is reading a stable value, we can use __this_cpu_read(). While this does reduce text size somewhat, this mostly results in code movement to .text.unlikely as a result of more/larger .cold. subfunctions. Less text on the hotpath is good for I$. $ ./compare.sh defconfig-build1 defconfig-build2 vmlinux.o setup_APIC_ibs 90 98 -12,+20 force_ibs_eilvt_setup 400 413 -57,+70 pci_serr_error 109 104 -54,+49 pci_serr_error 109 104 -54,+49 unknown_nmi_error 125 120 -76,+71 unknown_nmi_error 125 120 -76,+71 io_check_error 125 132 -97,+104 intel_thermal_interrupt 730 822 +92,+0 intel_init_thermal 951 945 -6,+0 generic_get_mtrr 301 294 -7,+0 generic_get_mtrr 301 294 -7,+0 generic_set_all 749 754 -44,+49 get_fixed_ranges 352 360 -41,+49 x86_acpi_suspend_lowlevel 369 363 -6,+0 check_tsc_sync_source 412 412 -71,+71 irq_migrate_all_off_this_cpu 662 674 -14,+26 clocksource_watchdog 748 748 -113,+113 __perf_event_account_interrupt 204 197 -7,+0 attempt_merge 1748 1741 -7,+0 intel_guc_send_ct 1424 1409 -15,+0 __fini_doorbell 235 231 -4,+0 bdw_set_cdclk 928 923 -5,+0 gen11_dsi_disable 1571 1556 -15,+0 gmbus_wait 493 488 -5,+0 md_make_request 376 369 -7,+0 __split_and_process_bio 543 536 -7,+0 delay_tsc 96 89 -7,+0 hsw_disable_pc8 696 691 -5,+0 tsc_verify_tsc_adjust 215 228 -22,+35 cpuidle_driver_unref 56 49 -7,+0 blk_account_io_completion 159 148 -11,+0 mtrr_wrmsr 95 99 -29,+33 __intel_wait_for_register_fw 401 419 +18,+0 cpuidle_driver_ref 43 36 -7,+0 cpuidle_get_driver 15 8 -7,+0 blk_account_io_done 535 528 -7,+0 irq_migrate_all_off_this_cpu 662 674 -14,+26 check_tsc_sync_source 412 412 -71,+71 irq_wait_for_poll 170 163 -7,+0 generic_end_io_acct 329 322 -7,+0 x86_acpi_suspend_lowlevel 369 363 -6,+0 nohz_balance_enter_idle 198 191 -7,+0 generic_start_io_acct 254 247 -7,+0 blk_account_io_start 341 334 -7,+0 perf_event_task_tick 682 675 -7,+0 intel_init_thermal 951 945 -6,+0 amd_e400_c1e_apic_setup 47 51 -28,+32 setup_APIC_eilvt 350 328 -22,+0 hsw_enable_pc8 1611 1605 -6,+0 total 12985947 12985892 -994,+939 Reported-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-27 16:48:51 +08:00
/*
* Allow the architecture to differentiate between a stable and unstable read.
* For example, x86 uses an IRQ-safe asm-volatile read for the unstable but a
* regular asm read for the stable.
*/
#ifndef __smp_processor_id
#define __smp_processor_id(x) raw_smp_processor_id(x)
#endif
#ifdef CONFIG_DEBUG_PREEMPT
extern unsigned int debug_smp_processor_id(void);
# define smp_processor_id() debug_smp_processor_id()
#else
x86/percpu: Relax smp_processor_id() Nadav reported that since this_cpu_read() became asm-volatile, many smp_processor_id() users generated worse code due to the extra constraints. However since smp_processor_id() is reading a stable value, we can use __this_cpu_read(). While this does reduce text size somewhat, this mostly results in code movement to .text.unlikely as a result of more/larger .cold. subfunctions. Less text on the hotpath is good for I$. $ ./compare.sh defconfig-build1 defconfig-build2 vmlinux.o setup_APIC_ibs 90 98 -12,+20 force_ibs_eilvt_setup 400 413 -57,+70 pci_serr_error 109 104 -54,+49 pci_serr_error 109 104 -54,+49 unknown_nmi_error 125 120 -76,+71 unknown_nmi_error 125 120 -76,+71 io_check_error 125 132 -97,+104 intel_thermal_interrupt 730 822 +92,+0 intel_init_thermal 951 945 -6,+0 generic_get_mtrr 301 294 -7,+0 generic_get_mtrr 301 294 -7,+0 generic_set_all 749 754 -44,+49 get_fixed_ranges 352 360 -41,+49 x86_acpi_suspend_lowlevel 369 363 -6,+0 check_tsc_sync_source 412 412 -71,+71 irq_migrate_all_off_this_cpu 662 674 -14,+26 clocksource_watchdog 748 748 -113,+113 __perf_event_account_interrupt 204 197 -7,+0 attempt_merge 1748 1741 -7,+0 intel_guc_send_ct 1424 1409 -15,+0 __fini_doorbell 235 231 -4,+0 bdw_set_cdclk 928 923 -5,+0 gen11_dsi_disable 1571 1556 -15,+0 gmbus_wait 493 488 -5,+0 md_make_request 376 369 -7,+0 __split_and_process_bio 543 536 -7,+0 delay_tsc 96 89 -7,+0 hsw_disable_pc8 696 691 -5,+0 tsc_verify_tsc_adjust 215 228 -22,+35 cpuidle_driver_unref 56 49 -7,+0 blk_account_io_completion 159 148 -11,+0 mtrr_wrmsr 95 99 -29,+33 __intel_wait_for_register_fw 401 419 +18,+0 cpuidle_driver_ref 43 36 -7,+0 cpuidle_get_driver 15 8 -7,+0 blk_account_io_done 535 528 -7,+0 irq_migrate_all_off_this_cpu 662 674 -14,+26 check_tsc_sync_source 412 412 -71,+71 irq_wait_for_poll 170 163 -7,+0 generic_end_io_acct 329 322 -7,+0 x86_acpi_suspend_lowlevel 369 363 -6,+0 nohz_balance_enter_idle 198 191 -7,+0 generic_start_io_acct 254 247 -7,+0 blk_account_io_start 341 334 -7,+0 perf_event_task_tick 682 675 -7,+0 intel_init_thermal 951 945 -6,+0 amd_e400_c1e_apic_setup 47 51 -28,+32 setup_APIC_eilvt 350 328 -22,+0 hsw_enable_pc8 1611 1605 -6,+0 total 12985947 12985892 -994,+939 Reported-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-27 16:48:51 +08:00
# define smp_processor_id() __smp_processor_id()
#endif
x86/percpu: Relax smp_processor_id() Nadav reported that since this_cpu_read() became asm-volatile, many smp_processor_id() users generated worse code due to the extra constraints. However since smp_processor_id() is reading a stable value, we can use __this_cpu_read(). While this does reduce text size somewhat, this mostly results in code movement to .text.unlikely as a result of more/larger .cold. subfunctions. Less text on the hotpath is good for I$. $ ./compare.sh defconfig-build1 defconfig-build2 vmlinux.o setup_APIC_ibs 90 98 -12,+20 force_ibs_eilvt_setup 400 413 -57,+70 pci_serr_error 109 104 -54,+49 pci_serr_error 109 104 -54,+49 unknown_nmi_error 125 120 -76,+71 unknown_nmi_error 125 120 -76,+71 io_check_error 125 132 -97,+104 intel_thermal_interrupt 730 822 +92,+0 intel_init_thermal 951 945 -6,+0 generic_get_mtrr 301 294 -7,+0 generic_get_mtrr 301 294 -7,+0 generic_set_all 749 754 -44,+49 get_fixed_ranges 352 360 -41,+49 x86_acpi_suspend_lowlevel 369 363 -6,+0 check_tsc_sync_source 412 412 -71,+71 irq_migrate_all_off_this_cpu 662 674 -14,+26 clocksource_watchdog 748 748 -113,+113 __perf_event_account_interrupt 204 197 -7,+0 attempt_merge 1748 1741 -7,+0 intel_guc_send_ct 1424 1409 -15,+0 __fini_doorbell 235 231 -4,+0 bdw_set_cdclk 928 923 -5,+0 gen11_dsi_disable 1571 1556 -15,+0 gmbus_wait 493 488 -5,+0 md_make_request 376 369 -7,+0 __split_and_process_bio 543 536 -7,+0 delay_tsc 96 89 -7,+0 hsw_disable_pc8 696 691 -5,+0 tsc_verify_tsc_adjust 215 228 -22,+35 cpuidle_driver_unref 56 49 -7,+0 blk_account_io_completion 159 148 -11,+0 mtrr_wrmsr 95 99 -29,+33 __intel_wait_for_register_fw 401 419 +18,+0 cpuidle_driver_ref 43 36 -7,+0 cpuidle_get_driver 15 8 -7,+0 blk_account_io_done 535 528 -7,+0 irq_migrate_all_off_this_cpu 662 674 -14,+26 check_tsc_sync_source 412 412 -71,+71 irq_wait_for_poll 170 163 -7,+0 generic_end_io_acct 329 322 -7,+0 x86_acpi_suspend_lowlevel 369 363 -6,+0 nohz_balance_enter_idle 198 191 -7,+0 generic_start_io_acct 254 247 -7,+0 blk_account_io_start 341 334 -7,+0 perf_event_task_tick 682 675 -7,+0 intel_init_thermal 951 945 -6,+0 amd_e400_c1e_apic_setup 47 51 -28,+32 setup_APIC_eilvt 350 328 -22,+0 hsw_enable_pc8 1611 1605 -6,+0 total 12985947 12985892 -994,+939 Reported-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-27 16:48:51 +08:00
#define get_cpu() ({ preempt_disable(); __smp_processor_id(); })
#define put_cpu() preempt_enable()
/*
* Callback to arch code if there's nosmp or maxcpus=0 on the
* boot command line:
*/
extern void arch_disable_smp_support(void);
extern void arch_thaw_secondary_cpus_begin(void);
extern void arch_thaw_secondary_cpus_end(void);
void smp_setup_processor_id(void);
int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par,
bool phys);
/* SMP core functions */
int smpcfd_prepare_cpu(unsigned int cpu);
int smpcfd_dead_cpu(unsigned int cpu);
int smpcfd_dying_cpu(unsigned int cpu);
#endif /* __LINUX_SMP_H */