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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-05-01 12:23:16 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-05-01 13:23:43 +0200 |
| commit | c33a0bc4e41ef169d6e807d8abb9502544b518e5 (patch) | |
| tree | f7ba55205352cd91a4f86999710008e89932ef10 /Documentation | |
| parent | 3c56999eec7acc105a31b4546c94aad2fb844b13 (diff) | |
perf_counter: fix race in perf_output_*
When two (or more) contexts output to the same buffer, it is possible
to observe half written output.
Suppose we have CPU0 doing perf_counter_mmap(), CPU1 doing
perf_counter_overflow(). If CPU1 does a wakeup and exposes head to
user-space, then CPU2 can observe the data CPU0 is still writing.
[ Impact: fix occasionally corrupted profiling records ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090501102533.007821627@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation')
0 files changed, 0 insertions, 0 deletions