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Groups > linux.kernel > #1272013
| From | "Wangnan (F)" <wangnan0@huawei.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction |
| Date | 2015-11-18 10:20 +0100 |
| Message-ID | <qw74e-WO-19@gated-at.bofh.it> (permalink) |
| References | <qw5lL-8cX-3@gated-at.bofh.it> <qw6Bc-vx-11@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 2015/11/18 16:48, Jiri Olsa wrote: > On Wed, Nov 18, 2015 at 03:20:36PM +0800, Wangnan (F) wrote: > > SNIP > >> Then use perf to trace it: >> >> # ./pref record -g -F 9 --call-graph dwarf ./test_dwarf_unwind >> # ./perf report --no-children --stdio >> ... >> 1.23% test_dwarf_unwi test_dwarf_unwind [.] funcc >> | >> ---funcc >> | >> |--0.62%-- funcb >> | funca >> | main >> | __libc_start_main >> | _start >> | >> --0.62%-- 0 <-- I applied Jiri's patch in [1] so see this >> 0, >> which indicates a broken call chain. > can't see this case after multiple running your test, > just the 'end-of-the-callchain' zeros > > 49.14% test_dwarf_unwi [vdso] [.] __vdso_gettimeofday > | > ---__vdso_gettimeofday > funcc > funcb > funca > main > __libc_start_main > _start > 0 > > 40.78% test_dwarf_unwi [vdso] [.] 0x0000000000000987 > | > ---0x7ffe28ab7987 > __vdso_gettimeofday > funcc > funcb > funca > main > __libc_start_main > _start > 0 > > > what kernel do you have? My kernel is 4.3-rc4. Please see my reply to Ingo. It is possible a problem related to hardware and PEBS? Maybe on your system perf never capture samples on 'callq'? I tested 'cycle' and 'cycle:p', can't get such samples. Only 'cycles:pp' (the default event) have this problem. Thank you. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-18 08:30 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-18 09:20 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction Ingo Molnar <mingo@kernel.org> - 2015-11-18 09:30 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-18 10:00 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction Ingo Molnar <mingo@kernel.org> - 2015-11-19 07:40 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-19 07:50 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction Ingo Molnar <mingo@kernel.org> - 2015-11-19 11:30 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-19 11:50 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction Peter Zijlstra <peterz@infradead.org> - 2015-11-19 12:30 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction Peter Zijlstra <peterz@infradead.org> - 2015-11-19 12:30 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction Ingo Molnar <mingo@kernel.org> - 2015-11-27 09:40 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction Peter Zijlstra <peterz@infradead.org> - 2015-11-30 10:30 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-18 10:10 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction Jiri Olsa <jolsa@redhat.com> - 2015-11-18 09:50 +0100
Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction "Wangnan (F)" <wangnan0@huawei.com> - 2015-11-18 10:20 +0100
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