It doesn't make sense to take up-to _4_ references on perf_sched_events per event, avoid doing this. Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3493,11 +3493,13 @@ static void unaccount_event_cpu(struct p static void unaccount_event(struct perf_event *event) { + bool dec = false; + if (event->parent) return; if (event->attach_state & PERF_ATTACH_TASK) - static_key_slow_dec_deferred(&perf_sched_events); + dec = true; if (event->attr.mmap || event->attr.mmap_data) atomic_dec(&nr_mmap_events); if (event->attr.comm) @@ -3507,12 +3509,15 @@ static void unaccount_event(struct perf_ if (event->attr.freq) atomic_dec(&nr_freq_events); if (event->attr.context_switch) { - static_key_slow_dec_deferred(&perf_sched_events); + dec = true; atomic_dec(&nr_switch_events); } if (is_cgroup_event(event)) - static_key_slow_dec_deferred(&perf_sched_events); + dec = true; if (has_branch_stack(event)) + dec = true; + + if (dec) static_key_slow_dec_deferred(&perf_sched_events); unaccount_event_cpu(event, event->cpu); @@ -7728,11 +7733,13 @@ static void account_event_cpu(struct per static void account_event(struct perf_event *event) { + bool inc = false; + if (event->parent) return; if (event->attach_state & PERF_ATTACH_TASK) - static_key_slow_inc(&perf_sched_events.key); + inc = true; if (event->attr.mmap || event->attr.mmap_data) atomic_inc(&nr_mmap_events); if (event->attr.comm) @@ -7745,11 +7752,14 @@ static void account_event(struct perf_ev } if (event->attr.context_switch) { atomic_inc(&nr_switch_events); - static_key_slow_inc(&perf_sched_events.key); + inc = true; } if (has_branch_stack(event)) - static_key_slow_inc(&perf_sched_events.key); + inc = true; if (is_cgroup_event(event)) + inc = true; + + if (inc) static_key_slow_inc(&perf_sched_events.key); account_event_cpu(event, event->cpu);