mainline inclusion from mainline-v6.3-rc1 commit 7c182722a0a9447e31f9645de4f311e5bc59b480 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7OIXK
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Add a function nr_context_switches_cpu() that returns number of context switches since boot on the specified CPU. This information will be used to diagnose RCU CPU stalls.
Signed-off-by: Zhen Lei thunder.leizhen@huawei.com Cc: Ingo Molnar mingo@redhat.com Cc: Peter Zijlstra peterz@infradead.org Cc: Juri Lelli juri.lelli@redhat.com Cc: Vincent Guittot vincent.guittot@linaro.org Cc: Dietmar Eggemann dietmar.eggemann@arm.com Cc: Steven Rostedt rostedt@goodmis.org Cc: Ben Segall bsegall@google.com Cc: Mel Gorman mgorman@suse.de Cc: Daniel Bristot de Oliveira bristot@redhat.com Cc: Valentin Schneider vschneid@redhat.com Reviewed-by: Frederic Weisbecker frederic@kernel.org Signed-off-by: Paul E. McKenney paulmck@kernel.org Signed-off-by: Zhen Lei thunder.leizhen@huawei.com --- include/linux/kernel_stat.h | 1 + kernel/sched/core.c | 5 +++++ 2 files changed, 6 insertions(+)
diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h index 6f467f0cf0bb768..1df2319ee0949a9 100644 --- a/include/linux/kernel_stat.h +++ b/include/linux/kernel_stat.h @@ -49,6 +49,7 @@ DECLARE_PER_CPU(struct kernel_cpustat, kernel_cpustat); #define kstat_cpu(cpu) per_cpu(kstat, cpu) #define kcpustat_cpu(cpu) per_cpu(kernel_cpustat, cpu)
+extern unsigned long long nr_context_switches_cpu(int cpu); extern unsigned long long nr_context_switches(void);
extern unsigned int kstat_irqs_cpu(unsigned int irq, int cpu); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2e4cdc439e02e37..b9e312c6f35637e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4264,6 +4264,11 @@ bool single_task_running(void) } EXPORT_SYMBOL(single_task_running);
+unsigned long long nr_context_switches_cpu(int cpu) +{ + return cpu_rq(cpu)->nr_switches; +} + unsigned long long nr_context_switches(void) { int i;