diff options
author | Frederic Weisbecker <fweisbec@gmail.com> | 2015-02-16 19:20:07 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2015-02-18 14:27:38 +0100 |
commit | 06b1f8083d6ed379ec1207a96339f23e8f7abfcf (patch) | |
tree | 4a26cb052b35a5fa11e7d731d367b3e34bf5cdfa /lib/dec_and_lock.c | |
parent | a79ec89fd8459f0de850898f432a2a57d60e64de (diff) |
sched: Fix preempt_schedule_common() triggering tracing recursion
Since the function graph tracer needs to disable preemption, it might
call preempt_schedule() after reenabling it if something triggered the
need for rescheduling in between.
Therefore we can't trace preempt_schedule() itself because we would
face a function tracing recursion otherwise as the tracer is always
called before PREEMPT_ACTIVE gets set to prevent that recursion. This is
why preempt_schedule() is tagged as "notrace".
But the same issue applies to every function called by preempt_schedule()
before PREEMPT_ACTIVE is actually set. And preempt_schedule_common() is
one such example. Unfortunately we forgot to tag it as notrace as well
and as a result we are encountering tracing recursion since it got
introduced by:
a18b5d0181923 ("sched: Fix missing preemption opportunity")
Let's fix that by applying the appropriate function tag to
preempt_schedule_common().
Reported-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1424110807-15057-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib/dec_and_lock.c')
0 files changed, 0 insertions, 0 deletions