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| author | Anton Blanchard <anton@samba.org> | 2012-02-15 18:48:22 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-02-29 16:33:39 -0800 |
| commit | 49f936fe90802f0923f47d28f755c83d358feac9 (patch) | |
| tree | 2f67de36aed0796d872c94f8a1f67f1690af0528 /drivers/gpu | |
| parent | 8507fb05c966cdd3a808bb267d2595a41db87512 (diff) | |
| download | kernel_samsung_smdk4412-49f936fe90802f0923f47d28f755c83d358feac9.zip kernel_samsung_smdk4412-49f936fe90802f0923f47d28f755c83d358feac9.tar.gz kernel_samsung_smdk4412-49f936fe90802f0923f47d28f755c83d358feac9.tar.bz2 | |
powerpc/perf: power_pmu_start restores incorrect values, breaking frequency events
commit 9a45a9407c69d068500923480884661e2b9cc421 upstream.
perf on POWER stopped working after commit e050e3f0a71b (perf: Fix
broken interrupt rate throttling). That patch exposed a bug in
the POWER perf_events code.
Since the PMCs count upwards and take an exception when the top bit
is set, we want to write 0x80000000 - left in power_pmu_start. We were
instead programming in left which effectively disables the counter
until we eventually hit 0x80000000. This could take seconds or longer.
With the patch applied I get the expected number of samples:
SAMPLE events: 9948
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu')
0 files changed, 0 insertions, 0 deletions