diff options
| author | Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu> | 2019-10-10 11:51:01 -0700 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-10-12 20:49:33 -0400 |
| commit | fc64e4ad80d4b72efce116f87b3174f0b7196f8e (patch) | |
| tree | f4c1f3db8217dd7afa8b988c19684535b1d04068 | |
| parent | 98dc19c11470ee6048aba723d77079ad2cda8a52 (diff) | |
tracing/hwlat: Don't ignore outer-loop duration when calculating max_latency
max_latency is intended to record the maximum ever observed hardware
latency, which may occur in either part of the loop (inner/outer). So
we need to also consider the outer-loop sample when updating
max_latency.
Link: http://lkml.kernel.org/r/157073345463.17189.18124025522664682811.stgit@srivatsa-ubuntu
Fixes: e7c15cd8a113 ("tracing: Added hardware latency tracer")
Cc: stable@vger.kernel.org
Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/trace_hwlat.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c index a0251a78807d..862f4b0139fc 100644 --- a/kernel/trace/trace_hwlat.c +++ b/kernel/trace/trace_hwlat.c @@ -256,6 +256,8 @@ static int get_sample(void) /* Keep a running maximum ever recorded hardware latency */ if (sample > tr->max_latency) tr->max_latency = sample; + if (outer_sample > tr->max_latency) + tr->max_latency = outer_sample; } out: |