diff options
| author | Anton Blanchard <anton@samba.org> | 2014-05-29 08:15:38 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-17 15:39:50 -0700 |
| commit | 7b9eab8f52499099d3b6351a7fd4277455666fa7 (patch) | |
| tree | f002a392de94a0f347aba0d0a164cc319e471e07 /kernel/rtmutex-debug.h | |
| parent | 30bbd3940f341bfd836e3afcac424c5a9ae19115 (diff) | |
powerpc/perf: Never program book3s PMCs with values >= 0x80000000
commit f56029410a13cae3652d1f34788045c40a13ffc7 upstream.
We are seeing a lot of PMU warnings on POWER8:
Can't find PMC that caused IRQ
Looking closer, the active PMC is 0 at this point and we took a PMU
exception on the transition from negative to 0. Some versions of POWER8
have an issue where they edge detect and not level detect PMC overflows.
A number of places program the PMC with (0x80000000 - period_left),
where period_left can be negative. We can either fix all of these or
just ensure that period_left is always >= 1.
This patch takes the second option.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/rtmutex-debug.h')
0 files changed, 0 insertions, 0 deletions