diff options
| author | Anton Blanchard <anton@samba.org> | 2014-05-29 08:15:38 +1000 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-07-18 15:51:20 +0200 |
| commit | a348a994e4312b0566c72ec49d72a4a754e267d8 (patch) | |
| tree | 8eccd7d283299937539f4b04fa1823bd164fce29 /lib/cpu-notifier-error-inject.c | |
| parent | 8c1eb0393ccc6ab3e79fae8a1e7dcd538f0af010 (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: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'lib/cpu-notifier-error-inject.c')
0 files changed, 0 insertions, 0 deletions