lkml.org 
[lkml]   [2016]   [Feb]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[PATCH 10/12] perf: Fix scaling vs perf_event_enable
    Similar to the perf_enable_on_exec(), ensure that event timings are
    consistent across perf_event_enable().

    Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    ---
    kernel/events/core.c | 42 +++++++++++++++++++++++-------------------
    1 file changed, 23 insertions(+), 19 deletions(-)

    --- a/kernel/events/core.c
    +++ b/kernel/events/core.c
    @@ -2069,14 +2069,27 @@ static void add_event_to_ctx(struct perf
    event->tstamp_stopped = tstamp;
    }

    -static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
    - struct perf_event_context *ctx);
    +static void ctx_sched_out(struct perf_event_context *ctx,
    + struct perf_cpu_context *cpuctx,
    + enum event_type_t event_type);
    static void
    ctx_sched_in(struct perf_event_context *ctx,
    struct perf_cpu_context *cpuctx,
    enum event_type_t event_type,
    struct task_struct *task);

    +static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
    + struct perf_event_context *ctx)
    +{
    + if (!cpuctx->task_ctx)
    + return;
    +
    + if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
    + return;
    +
    + ctx_sched_out(ctx, cpuctx, EVENT_ALL);
    +}
    +
    static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
    struct perf_event_context *ctx,
    struct task_struct *task)
    @@ -2227,17 +2240,18 @@ static void __perf_event_enable(struct p
    event->state <= PERF_EVENT_STATE_ERROR)
    return;

    - update_context_time(ctx);
    + if (ctx->is_active)
    + ctx_sched_out(ctx, cpuctx, EVENT_TIME);
    +
    __perf_event_mark_enabled(event);

    if (!ctx->is_active)
    return;

    if (!event_filter_match(event)) {
    - if (is_cgroup_event(event)) {
    - perf_cgroup_set_timestamp(current, ctx); // XXX ?
    + if (is_cgroup_event(event))
    perf_cgroup_defer_enabled(event);
    - }
    + ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
    return;
    }

    @@ -2245,8 +2259,10 @@ static void __perf_event_enable(struct p
    * If the event is in a group and isn't the group leader,
    * then don't put it on unless the group is on.
    */
    - if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
    + if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) {
    + ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
    return;
    + }

    task_ctx = cpuctx->task_ctx;
    if (ctx->task)
    @@ -2658,18 +2674,6 @@ void __perf_event_task_sched_out(struct
    perf_cgroup_sched_out(task, next);
    }

    -static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
    - struct perf_event_context *ctx)
    -{
    - if (!cpuctx->task_ctx)
    - return;
    -
    - if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
    - return;
    -
    - ctx_sched_out(ctx, cpuctx, EVENT_ALL);
    -}
    -
    /*
    * Called with IRQs disabled
    */

    \
     
     \ /
      Last update: 2016-02-24 19:41    [W:4.307 / U:0.000 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site