Messages in this thread | | | Date | Thu, 24 Nov 2016 15:27:47 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH 01/14] perf/x86: Introduce PERF_RECORD_OVERHEAD |
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On Thu, Nov 24, 2016 at 01:56:51PM +0000, Liang, Kan wrote: > > > > > > On Thu, Nov 24, 2016 at 01:45:28PM +0000, Liang, Kan wrote: > > > > I think we should make this optional/configurable like the rest of > > > > the aux events, like below.. > > > > > > > > > > The overhead logging only happens when event is going to be disabled > > > or the task is scheduling out. It should not be much and expensive. > > > > > > Peter, > > > > > > What do you think? > > > Should we make it configurable? > > > > Is there a downside to having it optional? > > NO. There will be no overhead information dumped into perf.data. Just like > current implementation.
old perf tools will get unexpected events if it's not optional
[root@ibm-x3650m4-01 perf]# ./perf c2c record -ag ^C[ perf record: Woken up 1 times to write data ] Warning: Found 1 unknown events!
Is this an older tool processing a perf.data file generated by a more recent tool?
If that is not the case, consider reporting to linux-kernel@vger.kernel.org.
[ perf record: Captured and wrote 2.333 MB perf.data (9370 samples) ]
jirka
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