On 11/2/2020 9:52 AM, Namhyung Kim wrote:
If an event associated with a PMU which has a sched_task callback, it should be called regardless of cpu/task context. For example,
I don't think it's necessary. We should call it when we have to. Otherwise, it just waste cycles.
Shouldn't the patch 2 be enough? Thanks, Kan
a per-cpu event might enable large PEBS buffers so it needs to flush the buffer whenever task scheduling happens. > The underlying PMU may or may not require this for the given event, but it will be handled in the pmu::sched_task() callback anyway. Signed-off-by: Namhyung Kim <[email protected]> --- kernel/events/core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index b458ed3dc81b..aaa0155c4142 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4696,6 +4696,8 @@ static void unaccount_event(struct perf_event *event) dec = true; if (has_branch_stack(event)) dec = true; + if (event->pmu->sched_task) + dec = true; if (event->attr.ksymbol) atomic_dec(&nr_ksymbol_events); if (event->attr.bpf_event) @@ -11225,6 +11227,8 @@ static void account_event(struct perf_event *event) inc = true; if (is_cgroup_event(event)) inc = true; + if (event->pmu->sched_task) + inc = true; if (event->attr.ksymbol) atomic_inc(&nr_ksymbol_events); if (event->attr.bpf_event)
