Messages in this thread | | | From | "Liang, Kan" <> | Subject | RE: [PATCH 01/14] perf/x86: Introduce PERF_RECORD_OVERHEAD | Date | Thu, 24 Nov 2016 14:39:26 +0000 |
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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 >
That's expected because a new record type is introduced.
OK, I will make it configurable. Anyway, there is nothing to lose. :)
Thanks, Kan
> [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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