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Groups > linux.kernel > #1447261
| From | Nikolay Borisov <kernel@kyup.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: Strange behavior of perf top with PEBS |
| Date | 2016-07-20 16:40 +0200 |
| Message-ID | <rX0Pf-2Cz-13@gated-at.bofh.it> (permalink) |
| References | <rWZJv-1YB-21@gated-at.bofh.it> <rX0Pf-2Cz-15@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 07/20/2016 05:34 PM, 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.. FYI running perf top -e instructions:p also produces no data on that particular CPU. > > I'll check why perf top forcing the precise for cycles > I thought we had that automated already > > jirka >
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Strange behavior of perf top with PEBS Nikolay Borisov <kernel@kyup.com> - 2016-07-20 15:30 +0200 Re: Strange behavior of perf top with PEBS Nikolay Borisov <kernel@kyup.com> - 2016-07-20 16:40 +0200 Re: Strange behavior of perf top with PEBS Jiri Olsa <jolsa@redhat.com> - 2016-07-20 16:40 +0200 Re: Strange behavior of perf top with PEBS Jiri Olsa <jolsa@redhat.com> - 2016-07-20 16:40 +0200
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