diff options
| author | James Hogan <james.hogan@imgtec.com> | 2013-02-27 21:54:51 +0000 |
|---|---|---|
| committer | James Hogan <james.hogan@imgtec.com> | 2013-03-15 13:20:15 +0000 |
| commit | 1fb4dc5c39af941d3abc597337e0ea776bfce0f2 (patch) | |
| tree | 3a5a08501b8f421de3d69263c0bad38bd95221d1 /arch/metag/kernel/perf | |
| parent | 9344de1b1c64b2217f3b15508266deff2a8d6c84 (diff) | |
metag: perf: don't reset TXTACTCYC
The thread active cycle counter TXTACTCYC is used in __delay so it
shouldn't really be reset to zero by perf. Fix perf to just read the
value, and instead of clearing it, record the prev_count value in
enable_counter so that the delta calculations know about the previous
value.
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>
Diffstat (limited to 'arch/metag/kernel/perf')
| -rw-r--r-- | arch/metag/kernel/perf/perf_event.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/arch/metag/kernel/perf/perf_event.c b/arch/metag/kernel/perf/perf_event.c index 54fde35b4b9c..a1eff3687e8e 100644 --- a/arch/metag/kernel/perf/perf_event.c +++ b/arch/metag/kernel/perf/perf_event.c @@ -617,9 +617,7 @@ static void metag_pmu_enable_counter(struct hw_perf_event *event, int idx) WARN_ONCE((config != 0x100), "invalid configuration (%d) for counter (%d)\n", config, idx); - - /* Reset the cycle count */ - __core_reg_set(TXTACTCYC, 0); + local64_set(&event->prev_count, __core_reg_get(TXTACTCYC)); goto unlock; } @@ -708,9 +706,8 @@ static u64 metag_pmu_read_counter(int idx) { u32 tmp = 0; - /* The act of reading the cycle counter also clears it */ if (METAG_INST_COUNTER == idx) { - __core_reg_swap(TXTACTCYC, tmp); + tmp = __core_reg_get(TXTACTCYC); goto out; } |