• Frederic Weisbecker's avatar
    tracing/events: don't use wake up for events · 07edf712
    Frederic Weisbecker authored
    Impact: fix hard-lockup with sched switch events
    Some ftrace events, such as sched wakeup, can be traced
    while the runqueue lock is hold. Since they are using
    trace_current_buffer_unlock_commit(), they call wake_up()
    which can try to grab the runqueue lock too, resulting in
    a deadlock.
    Now for all event, we call a new helper:
    trace_nowake_buffer_unlock_commit() which do pretty the same than
    trace_current_buffer_unlock_commit() except than it doesn't call
    Reported-by: default avatarIngo Molnar <mingo@elte.hu>
    Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
    Cc: Steven Rostedt <rostedt@goodmis.org>
    LKML-Reference: <1237759847-21025-4-git-send-email-fweisbec@gmail.com>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>