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| author | James Hogan <james.hogan@imgtec.com> | 2013-02-27 17:16:38 +0100 |
|---|---|---|
| committer | James Hogan <james.hogan@imgtec.com> | 2013-03-15 14:19:54 +0100 |
| commit | c43ca04b5e7854b3996f84a495e4553941e76266 (patch) | |
| tree | 73cd4ed7b8ef214b8d9cd366611b566303628a2e | |
| parent | metag: perf: fix core internal / perf channel mux (diff) | |
| download | linux-c43ca04b5e7854b3996f84a495e4553941e76266.tar.xz linux-c43ca04b5e7854b3996f84a495e4553941e76266.zip | |
metag: perf: fix wrap handling in delta calculation
When calculating the delta, mask with MAX_PERIOD (24 bits) to handle
wrapping, which particularly happens with periodic sampling since the
value is intentionally set so that it will overflow soon.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
| -rw-r--r-- | arch/metag/kernel/perf/perf_event.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/metag/kernel/perf/perf_event.c b/arch/metag/kernel/perf/perf_event.c index f38bf6d4dc55..8096db2a550b 100644 --- a/arch/metag/kernel/perf/perf_event.c +++ b/arch/metag/kernel/perf/perf_event.c @@ -211,7 +211,7 @@ again: /* * Calculate the delta and add it to the counter. */ - delta = new_raw_count - prev_raw_count; + delta = (new_raw_count - prev_raw_count) & MAX_PERIOD; local64_add(delta, &event->count); } |