Messages in this thread | | | Subject | Re: [PATCH 03/28] perf tools: Remove symbol_conf.use_callchain check | From | Namhyung Kim <> | Date | Thu, 09 Jan 2014 22:16:36 +0900 |
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2014-01-08 (수), 09:57 -0300, Arnaldo Carvalho de Melo: > Em Wed, Jan 08, 2014 at 05:46:08PM +0900, Namhyung Kim escreveu: > > The machine__resolve_callchain() is called only if symbol_conf. > > use_callchain is set so no need to check it again. > > Not really it may be called with use_callchain not set, I'm checking if > the logic is needed (doesn't look like).
To be more precise, it's called with use_callchain not set - if "--sort parent" was given on the command line. But even in this case we need to proceed the callchain traversal, if not the parent column will have invalid results since it only sees the first entry (usually itself) and then stops.
$ perf report -s sym,parent + 2.66% [k] rb_next sys_ioctl + 1.52% [.] pthread_mutex_lock [other] + 0.92% [k] page_fault [other] + 0.92% [.] 0x00000000008dca3f [other] + 0.86% [.] 0x0000000000a052e9 [other] + 0.76% [.] pthread_mutex_unlock [other] + 0.73% [.] 0x0000000000976361 [other] + 0.69% [k] find_vma sys_mmap_pgoff
$ perf report -s sym,parent -g none + 2.66% [k] rb_next [other] + 1.52% [.] pthread_mutex_lock [other] + 0.92% [k] page_fault [other] + 0.92% [.] 0x00000000008dca3f [other] + 0.86% [.] 0x0000000000a052e9 [other] + 0.76% [.] pthread_mutex_unlock [other] + 0.73% [.] 0x0000000000976361 [other] + 0.69% [k] find_vma [other]
With --children patchset, we'll need to traverse the callstack regardless of the use_callchain anyway. So we need this patch.
Thanks, Namhyung
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