Messages in this thread | | | Date | Wed, 21 Feb 2018 15:37:23 +0100 | From | Jiri Olsa <> | Subject | Re: [PATCH 2/2] perf, tools, stat: Reset ids counter when retrying events |
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On Wed, Feb 21, 2018 at 11:33:37AM -0300, Arnaldo Carvalho de Melo wrote: > Em Wed, Feb 21, 2018 at 03:31:17PM +0100, Jiri Olsa escreveu: > > On Thu, Oct 05, 2017 at 07:00:29PM -0700, Andi Kleen wrote: > > > From: Andi Kleen <ak@linux.intel.com> > > > > ouch, sry for overlooking this > > > > > > > > perf stat can retry opening events. After opening an file descriptor > > > it adds the ids to the ecsel. Each event keeps a running > > > count of ids. When we decide to close an evsel and retry > > > with a different configuration this count needs to be reset, > > > otherwise it can overflow the buffer. > > > > how can this happen? we call store_counter_ids at the > > end of the loop, when the evsel is all done and can't > > be reconfigured > > Yeah, I couldn't figure out the exact sequence, but I think that we need > to reset those hash tables when doing a perf_evlist__close(), no? I.e. > when we open we may get new ids, so need to rehash?
yes, I think we should reset it any time the event is closed I'll check your changes
jirka
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