Messages in this thread Patch in this message | | | Date | Tue, 9 Sep 2014 07:52:53 -0700 | From | tip-bot for Andreea-Cristina Bernat <> | Subject | [tip:perf/core] perf/callchain: Replace rcu_assign_pointer() with RCU_INIT_POINTER() |
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Commit-ID: e0455e194a5e0cf49bc7596a20d4f7e47995b9c6 Gitweb: http://git.kernel.org/tip/e0455e194a5e0cf49bc7596a20d4f7e47995b9c6 Author: Andreea-Cristina Bernat <bernat.ada@gmail.com> AuthorDate: Fri, 22 Aug 2014 17:15:36 +0300 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Tue, 9 Sep 2014 06:53:04 +0200
perf/callchain: Replace rcu_assign_pointer() with RCU_INIT_POINTER()
The use of "rcu_assign_pointer()" is NULLing out the pointer. According to RCU_INIT_POINTER()'s block comment:
"1. This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a smaller overhead.
The following Coccinelle semantic patch was used: @@ @@
- rcu_assign_pointer + RCU_INIT_POINTER (..., NULL)
Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: paulmck@linux.vnet.ibm.com Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Link: http://lkml.kernel.org/r/20140822141536.GA32051@ada Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/events/callchain.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index 97b67df..f2a88de 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -52,7 +52,7 @@ static void release_callchain_buffers(void) struct callchain_cpus_entries *entries; entries = callchain_cpus_entries; - rcu_assign_pointer(callchain_cpus_entries, NULL); + RCU_INIT_POINTER(callchain_cpus_entries, NULL); call_rcu(&entries->rcu_head, release_callchain_buffers_rcu); }
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