Messages in this thread Patch in this message | | | Date | Wed, 2 Dec 2020 17:19:34 +0100 | From | Peter Zijlstra <> | Subject | Re: [RFC 1/2] perf core: Add PERF_COUNT_SW_CGROUP_SWITCHES event |
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On Thu, Dec 03, 2020 at 12:02:04AM +0900, Namhyung Kim wrote:
> +#ifdef CONFIG_CGROUP_PERF > +static inline void > +perf_sw_event_cgroup_switch(struct task_struct *prev, struct task_struct *next) > +{ > + struct cgroup *prev_cgrp, *next_cgrp; > + > + rcu_read_lock(); > + > + prev_cgrp = task_css_check(prev, perf_event_cgrp_id, 1)->cgroup; > + next_cgrp = task_css_check(next, perf_event_cgrp_id, 1)->cgroup; > + > + if (prev_cgrp != next_cgrp) > + perf_sw_event_sched(PERF_COUNT_SW_CGROUP_SWITCHES, 1, 0); > + > + rcu_read_unlock(); > +} > +#else > +static inline void perf_sw_event_cgroup_switch(struct task_struct *prev, > + struct task_struct *next) {} > +#endif /* CONFIG_CGROUP_PERF */ > + > extern struct static_key_false perf_sched_events; > > static __always_inline bool > @@ -1220,6 +1241,7 @@ static inline void perf_event_task_sched_out(struct task_struct *prev, > struct task_struct *next) > { > perf_sw_event_sched(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 0); > + perf_sw_event_cgroup_switch(prev, next); > > if (static_branch_unlikely(&perf_sched_events)) > __perf_event_task_sched_out(prev, next);
Urgh.. that's horrible, try something like this.
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 9a38f579bc76..5eb284819ee5 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1174,25 +1174,19 @@ DECLARE_PER_CPU(struct pt_regs, __perf_regs[4]); * which is guaranteed by us not actually scheduling inside other swevents * because those disable preemption. */ -static __always_inline void -perf_sw_event_sched(u32 event_id, u64 nr, u64 addr) +static __always_inline void __perf_sw_event_sched(u32 event_id, u64 nr, u64 addr) { - if (static_key_false(&perf_swevent_enabled[event_id])) { - struct pt_regs *regs = this_cpu_ptr(&__perf_regs[0]); + struct pt_regs *regs = this_cpu_ptr(&__perf_regs[0]); - perf_fetch_caller_regs(regs); - ___perf_sw_event(event_id, nr, regs, addr); - } + perf_fetch_caller_regs(regs); + ___perf_sw_event(event_id, nr, regs, addr); } extern struct static_key_false perf_sched_events; -static __always_inline bool -perf_sw_migrate_enabled(void) +static __always_inline bool __perf_sw_enabled(int swevt) { - if (static_key_false(&perf_swevent_enabled[PERF_COUNT_SW_CPU_MIGRATIONS])) - return true; - return false; + return static_key_false(&perf_swevent_enabled[swevt]); } static inline void perf_event_task_migrate(struct task_struct *task) @@ -1207,11 +1201,9 @@ static inline void perf_event_task_sched_in(struct task_struct *prev, if (static_branch_unlikely(&perf_sched_events)) __perf_event_task_sched_in(prev, task); - if (perf_sw_migrate_enabled() && task->sched_migrated) { - struct pt_regs *regs = this_cpu_ptr(&__perf_regs[0]); - - perf_fetch_caller_regs(regs); - ___perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, regs, 0); + if (__perf_sw_enabled(PERF_COUNT_SW_CPU_MIGRATIONS) && + task->sched_migrated) { + __perf_sw_event_sched(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 0); task->sched_migrated = 0; } } @@ -1219,7 +1211,13 @@ static inline void perf_event_task_sched_in(struct task_struct *prev, static inline void perf_event_task_sched_out(struct task_struct *prev, struct task_struct *next) { - perf_sw_event_sched(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 0); + if (__perf_sw_enabled(PERF_COUNT_SW_CONTEXT_SWITCHES)) + __perf_sw_event_sched(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 0); + + if (__perf_sw_enabled(PERF_COUNT_SW_CGROUP_SWITCHES) && + (task_css_check(prev, perf_event_cgrp_id, 1)->cgroup != + task_css_check(next, perf_event_cgrp_id, 1)->cgroup)) + __perf_sw_event_sched(PERF_COUNT_SW_CGROUP_SWITCHES, 1, 0); if (static_branch_unlikely(&perf_sched_events)) __perf_event_task_sched_out(prev, next); @@ -1475,8 +1473,6 @@ static inline int perf_event_refresh(struct perf_event *event, int refresh) static inline void perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) { } static inline void -perf_sw_event_sched(u32 event_id, u64 nr, u64 addr) { } -static inline void perf_bp_event(struct perf_event *event, void *data) { } static inline int perf_register_guest_info_callbacks
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