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... -------------------------------- 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; -- 2.34.1