Messages in this thread | | | Subject | Re: [PATCH 3/3] perf events: add timehist option to record and report | From | Peter Zijlstra <> | Date | Fri, 18 Feb 2011 19:39:59 +0100 |
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On Fri, 2011-02-18 at 11:07 -0700, David Ahern wrote: > We want not only context-switch events, but the stack trace at the > switch.
Both ftrace and perf can do that:
perf record -ge sched:sched_switch -c 1
or
echo 1 > /debug/tracing/options/stacktrace
> That data along with the gettimeofday timestamp has allowed us to > resolve performance issues such as a system call taking longer than > expected during a specific sequence of events or a process getting > preempted and not scheduled for N seconds. etc., etc.
Non of that seems to require GTOD stamps.
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