Commit f971e511 authored Nov 27, 2017 by Mark Rutland Committed by Ingo Molnar Dec 12, 2017

tools/perf: Convert ACCESS_ONCE() to READ_ONCE()



Recently there was a treewide conversion of ACCESS_ONCE() to
{READ,WRITE}_ONCE(), but a new use was introduced concurrently by
commit:

  16958497 ("perf mmap: Move perf_mmap and methods to separate mmap.[ch] files")

Let's convert this over to READ_ONCE() so that we can remove the
ACCESS_ONCE() definitions in subsequent patches.

Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: apw@canonical.com
Link: http://lkml.kernel.org/r/20171127103824.36526-2-mark.rutland@arm.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent e966eaee

tools/perf/util/mmap.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -70,7 +70,7 @@ void perf_mmap__read_catchup(struct perf_mmap *md);
		static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
		{
		struct perf_event_mmap_page *pc = mm->base;
		u64 head = ACCESS_ONCE(pc->data_head);
		u64 head = READ_ONCE(pc->data_head);
		rmb();
		return head;
		}

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