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Groups > linux.kernel > #1456496
| From | Jiri Olsa <jolsa@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: Strange behavior of perf top with PEBS |
| Date | 2016-08-04 17:40 +0200 |
| Message-ID | <s2sUy-2Lw-31@gated-at.bofh.it> (permalink) |
| References | <rWZJv-1YB-21@gated-at.bofh.it> <rX0Pf-2Cz-15@gated-at.bofh.it> <rX0Pf-2Cz-21@gated-at.bofh.it> <rZ8Sm-1mU-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue, Jul 26, 2016 at 02:30:46PM +0300, Nikolay Borisov wrote: > > > On 07/20/2016 05:38 PM, Jiri Olsa wrote: > > On Wed, Jul 20, 2016 at 04:34:17PM +0200, Jiri Olsa wrote: > >> On Wed, Jul 20, 2016 at 04:28:34PM +0300, Nikolay Borisov wrote: > >>> Hello, > >>> > >>> Running perf version 4.4.14.g0cb188d (no modification to the PMU/perf > >>> code) I observed that "perf top" counts no cycles and produces no > >>> output. After a bit of head scratching and testing I figured that > >>> running "perf top -e cycles" actually works whereas the default option > >>> is equivalent to running "perf top -e cycles:p". So the latter version > >>> seems to not work on my machine. > >> > >> hum, I think Core2 has PEBs valid only for instructions not cycles.. > >> > >> I'll check why perf top forcing the precise for cycles > >> I thought we had that automated already > > > > oops, too soon ;) we have: > > > > perf/x86/intel: Fix Core2,Atom,NHM,WSM cycles:pp events > > commit 517e6341fa123ec3a2f9ea78ad547be910529881 > > Author: Peter Zijlstra <peterz@infradead.org> > > Date: Sat Apr 11 12:16:22 2015 +0200 > > > > > > so i guess it should work.. checking ;-) > > Any update on that? sorry for late response.. I checked on f22 kernel and it's missing the core2 PEBs fix: 1424a09a9e18 perf/x86: fix PEBS issues on Intel Atom/Core2 which was introduced in 4.5.. you should upgrade or include this patch jirka
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Re: Strange behavior of perf top with PEBS Nikolay Borisov <kernel@kyup.com> - 2016-07-26 13:40 +0200
Re: Strange behavior of perf top with PEBS Jiri Olsa <jolsa@redhat.com> - 2016-08-04 17:40 +0200
Re: Strange behavior of perf top with PEBS Nikolay Borisov <kernel@kyup.com> - 2016-08-05 11:40 +0200
Re: Strange behavior of perf top with PEBS Jiri Olsa <jolsa@redhat.com> - 2016-08-05 12:30 +0200
Re: Strange behavior of perf top with PEBS Peter Zijlstra <peterz@infradead.org> - 2016-08-08 15:10 +0200
Re: Strange behavior of perf top with PEBS Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-08-08 15:20 +0200
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