Commit 00a2916f authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Thomas Gleixner

perf: Fix running time accounting

A recent fix to the shadow timestamp inadvertly broke the running time
accounting.

We must not update the running timestamp if we fail to schedule the
event, the event will not have ran. This can (and did) result in
negative total runtime because the stopped timestamp was before the
running timestamp (we 'started' but never stopped the event -- because
it never really started we didn't have to stop it either).
Reported-and-Tested-by: default avatarVince Weaver <vincent.weaver@maine.edu>
Fixes: 72f669c0 ("perf: Update shadow timestamp before add event")
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # 4.1
Cc: Shaohua Li <shli@fb.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent cbfe8fa6
...@@ -1868,8 +1868,6 @@ event_sched_in(struct perf_event *event, ...@@ -1868,8 +1868,6 @@ event_sched_in(struct perf_event *event,
perf_pmu_disable(event->pmu); perf_pmu_disable(event->pmu);
event->tstamp_running += tstamp - event->tstamp_stopped;
perf_set_shadow_time(event, ctx, tstamp); perf_set_shadow_time(event, ctx, tstamp);
perf_log_itrace_start(event); perf_log_itrace_start(event);
...@@ -1881,6 +1879,8 @@ event_sched_in(struct perf_event *event, ...@@ -1881,6 +1879,8 @@ event_sched_in(struct perf_event *event,
goto out; goto out;
} }
event->tstamp_running += tstamp - event->tstamp_stopped;
if (!is_software_event(event)) if (!is_software_event(event))
cpuctx->active_oncpu++; cpuctx->active_oncpu++;
if (!ctx->nr_active++) if (!ctx->nr_active++)
......
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