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    Subject[tip:perf/urgent] perf_events: Fix FORK events
    Commit-ID:  6f93d0a7c83772997b81c30d6f519a9a5dbab6a9
    Gitweb: http://git.kernel.org/tip/6f93d0a7c83772997b81c30d6f519a9a5dbab6a9
    Author: Peter Zijlstra <peterz@infradead.org>
    AuthorDate: Sun, 14 Feb 2010 11:12:04 +0100
    Committer: Ingo Molnar <mingo@elte.hu>
    CommitDate: Sun, 14 Feb 2010 18:10:39 +0100

    perf_events: Fix FORK events

    Commit 22e19085 ("Honour event state for aux stream data")
    introduced a bug where we would drop FORK events.

    The thing is that we deliver FORK events to the child process'
    event, which at that time will be PERF_EVENT_STATE_INACTIVE
    because the child won't be scheduled in (we're in the middle of
    fork).

    Solve this twice, change the event state filter to exclude only
    disabled (STATE_OFF) or worse, and deliver FORK events to the
    current (parent).

    Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Anton Blanchard <anton@samba.org>
    Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
    LKML-Reference: <1266142324.5273.411.camel@laptop>
    Signed-off-by: Ingo Molnar <mingo@elte.hu>
    ---
    kernel/perf_event.c | 11 +++++------
    1 files changed, 5 insertions(+), 6 deletions(-)

    diff --git a/kernel/perf_event.c b/kernel/perf_event.c
    index 2b19297..2ae7409 100644
    --- a/kernel/perf_event.c
    +++ b/kernel/perf_event.c
    @@ -3259,8 +3259,6 @@ static void perf_event_task_output(struct perf_event *event,
    task_event->event_id.tid = perf_event_tid(event, task);
    task_event->event_id.ptid = perf_event_tid(event, current);

    - task_event->event_id.time = perf_clock();
    -
    perf_output_put(&handle, task_event->event_id);

    perf_output_end(&handle);
    @@ -3268,7 +3266,7 @@ static void perf_event_task_output(struct perf_event *event,

    static int perf_event_task_match(struct perf_event *event)
    {
    - if (event->state != PERF_EVENT_STATE_ACTIVE)
    + if (event->state < PERF_EVENT_STATE_INACTIVE)
    return 0;

    if (event->cpu != -1 && event->cpu != smp_processor_id())
    @@ -3300,7 +3298,7 @@ static void perf_event_task_event(struct perf_task_event *task_event)
    cpuctx = &get_cpu_var(perf_cpu_context);
    perf_event_task_ctx(&cpuctx->ctx, task_event);
    if (!ctx)
    - ctx = rcu_dereference(task_event->task->perf_event_ctxp);
    + ctx = rcu_dereference(current->perf_event_ctxp);
    if (ctx)
    perf_event_task_ctx(ctx, task_event);
    put_cpu_var(perf_cpu_context);
    @@ -3331,6 +3329,7 @@ static void perf_event_task(struct task_struct *task,
    /* .ppid */
    /* .tid */
    /* .ptid */
    + .time = perf_clock(),
    },
    };

    @@ -3380,7 +3379,7 @@ static void perf_event_comm_output(struct perf_event *event,

    static int perf_event_comm_match(struct perf_event *event)
    {
    - if (event->state != PERF_EVENT_STATE_ACTIVE)
    + if (event->state < PERF_EVENT_STATE_INACTIVE)
    return 0;

    if (event->cpu != -1 && event->cpu != smp_processor_id())
    @@ -3500,7 +3499,7 @@ static void perf_event_mmap_output(struct perf_event *event,
    static int perf_event_mmap_match(struct perf_event *event,
    struct perf_mmap_event *mmap_event)
    {
    - if (event->state != PERF_EVENT_STATE_ACTIVE)
    + if (event->state < PERF_EVENT_STATE_INACTIVE)
    return 0;

    if (event->cpu != -1 && event->cpu != smp_processor_id())

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