diff options
| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2019-12-10 13:51:01 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2019-12-17 15:32:46 +0300 |
| commit | 92ca7da4bdc24d63bb0bcd241c11441ddb63b80a (patch) | |
| tree | 149940e4c77a558df00df7038a6aa6f6eb48942f /kernel/events | |
| parent | ff61541cc6c1962957758ba433c574b76f588d23 (diff) | |
| download | linux-92ca7da4bdc24d63bb0bcd241c11441ddb63b80a.tar.xz | |
perf/x86/intel: Fix PT PMI handling
Commit:
ccbebba4c6bf ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it")
skips the PT/LBR exclusivity check on CPUs where PT and LBRs coexist, but
also inadvertently skips the active_events bump for PT in that case, which
is a bug. If there aren't any hardware events at the same time as PT, the
PMI handler will ignore PT PMIs, as active_events reads zero in that case,
resulting in the "Uhhuh" spurious NMI warning and PT data loss.
Fix this by always increasing active_events for PT events.
Fixes: ccbebba4c6bf ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it")
Reported-by: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lkml.kernel.org/r/20191210105101.77210-1-alexander.shishkin@linux.intel.com
Diffstat (limited to 'kernel/events')
0 files changed, 0 insertions, 0 deletions