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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-06-10 22:53:37 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-06-11 02:39:01 +0200 |
| commit | 66fff22483d8542dfb4d61a28d21277bbde321e8 (patch) | |
| tree | 615c582da3ef5bb75063467e82e9c63b010b535e | |
| parent | f7b7c26e01e51fe46097e11f179dc71ce7950084 (diff) | |
| download | blackbird-op-linux-66fff22483d8542dfb4d61a28d21277bbde321e8.tar.gz blackbird-op-linux-66fff22483d8542dfb4d61a28d21277bbde321e8.zip | |
perf_counter: Annotate exit ctx recursion
Ever since Paul fixed it to unclone the context before taking the
ctx->lock this became a false positive, annotate it away.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | kernel/perf_counter.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 51c571ee4d0b..ae591a1275a6 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -3879,7 +3879,18 @@ void perf_counter_exit_task(struct task_struct *child) spin_unlock(&child_ctx->lock); local_irq_restore(flags); - mutex_lock(&child_ctx->mutex); + /* + * We can recurse on the same lock type through: + * + * __perf_counter_exit_task() + * sync_child_counter() + * fput(parent_counter->filp) + * perf_release() + * mutex_lock(&ctx->mutex) + * + * But since its the parent context it won't be the same instance. + */ + mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING); again: list_for_each_entry_safe(child_counter, tmp, &child_ctx->counter_list, |
