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| author |  Peter Zijlstra <peterz@infradead.org>
| 2013-10-30 11:42:46 +0100 |
|---|---|---|
| committer |  Ingo Molnar <mingo@kernel.org>
| 2013-11-06 12:34:26 +0100 |
| commit | a94d342b9cb09edfe888ea972af0883b6a8d992b (patch) | |
| tree | dd3af73c84e210548c79d32dafbe4fadb2a42eb9 /tools/perf/util/evlist.h | |
| parent | perf: Fix arch_perf_out_copy_user default (diff) | |
| download | linux-a94d342b9cb09edfe888ea972af0883b6a8d992b.tar.gz linux-a94d342b9cb09edfe888ea972af0883b6a8d992b.tar.bz2 linux-a94d342b9cb09edfe888ea972af0883b6a8d992b.zip | |
tools/perf: Add required memory barriers
To match patch bf378d341e48 ("perf: Fix perf ring buffer memory
ordering") change userspace to also adhere to the ordering outlined.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Neuling <mikey@neuling.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: james.hogan@imgtec.com
Cc: Vince Weaver <vince@deater.net>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Michael Ellerman <michael@ellerman.id.au>
Link: http://lkml.kernel.org/r/20131030104246.GH16117@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/perf/util/evlist.h')
| -rw-r--r-- | tools/perf/util/evlist.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index e99eaed92682..ecaa582f40e2 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -177,7 +177,7 @@ int perf_evlist__strerror_open(struct perf_evlist *evlist, int err, char *buf, s static inline unsigned int perf_mmap__read_head(struct perf_mmap *mm) { struct perf_event_mmap_page *pc = mm->base; - int head = pc->data_head; + int head = ACCESS_ONCE(pc->data_head); rmb(); return head; } @@ -190,7 +190,7 @@ static inline void perf_mmap__write_tail(struct perf_mmap *md, /* * ensure all reads are done before we write the tail out. */ - /* mb(); */ + mb(); pc->data_tail = tail; } |