diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-05-23 18:28:57 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-05-23 19:37:46 +0200 |
| commit | 682076ae1de0aba9c2da509f7b19dc03e30a6e1f (patch) | |
| tree | 63e48b23f8ef4e16b79c9b767def13e7795eb440 | |
| parent | fccc714b3148ab9741fafc1e90c3876d50df6093 (diff) | |
perf_counter: Sanitize context locking
Ensure we're consistent with the context locks.
context->mutex
context->lock
list_{add,del}_counter();
so that either lock is sufficient to stabilize the context.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090523163012.618790733@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | kernel/perf_counter.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 679c3b5bb7d..d162d2f0b27 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -597,6 +597,8 @@ static void add_counter_to_ctx(struct perf_counter *counter, /* * Cross CPU call to install and enable a performance counter + * + * Must be called with ctx->mutex held */ static void __perf_install_in_context(void *info) { @@ -1496,13 +1498,13 @@ static void perf_counter_for_each_sibling(struct perf_counter *counter, struct perf_counter_context *ctx = counter->ctx; struct perf_counter *sibling; - spin_lock_irq(&ctx->lock); + mutex_lock(&ctx->mutex); counter = counter->group_leader; func(counter); list_for_each_entry(sibling, &counter->sibling_list, list_entry) func(sibling); - spin_unlock_irq(&ctx->lock); + mutex_unlock(&ctx->mutex); } static void perf_counter_for_each_child(struct perf_counter *counter, @@ -3414,7 +3416,10 @@ __perf_counter_exit_task(struct task_struct *child, struct perf_counter *parent_counter; update_counter_times(child_counter); + + spin_lock_irq(&child_ctx->lock); list_del_counter(child_counter, child_ctx); + spin_unlock_irq(&child_ctx->lock); parent_counter = child_counter->parent; /* |