Hi Peter
Could you please have a look of this
thanks
2018-01-11 11:09 GMT+08:00 <linxiu...@gmail.com>:
> From: "leilei.lin" <leilei....@alibaba-inc.com>
>
> Do not install cgroup event into the CPU context if the cgroup
> is not running on this CPU
>
> While there is no task of cgroup running specified CPU, current
> kernel still install cgroup event into CPU context, that causes
> another cgroup event can't be installed into this CPU.
>
> Signed-off-by: leilei.lin <leilei....@alibaba-inc.com>
> ---
> kernel/events/core.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 4df5b69..19c587b 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -2284,6 +2284,7 @@ static int __perf_install_in_context(void *info)
> struct perf_event_context *ctx = event->ctx;
> struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
> struct perf_event_context *task_ctx = cpuctx->task_ctx;
> + struct perf_cgroup *cgrp;
> bool reprogram = true;
> int ret = 0;
>
> @@ -2311,6 +2312,19 @@ static int __perf_install_in_context(void *info)
> raw_spin_lock(&task_ctx->lock);
> }
>
> + if (event->cgrp) {
> + /*
> + * Only care about cgroup events.
> + *
> + * If only the task belongs to cgroup of this event,
> + * we will continue the installment
> + */
> + cgrp = perf_cgroup_from_task(current, ctx);
> + if (!cgroup_is_descendant(cgrp->css.cgroup,
> + event->cgrp->css.cgroup))
> + goto unlock;
> + }
> +
> if (reprogram) {
> ctx_sched_out(ctx, cpuctx, EVENT_TIME);
> add_event_to_ctx(event, ctx);
> --
> 2.8.4.31.g9ed660f
>
