Re: [PATCH v2 -tip] perf probe: Add fastpath to do lookup byfunction name
From: Arnaldo Carvalho de Melo
Date: Thu Mar 24 2011 - 22:58:14 EST
Em Fri, Mar 25, 2011 at 10:14:25AM +0900, Masami Hiramatsu escreveu:
> (2011/03/24 23:09), Lin Ming wrote:
> > v2 -> v1:
> > - Don't compare file names with cu_find_realpath(...), instead, compare them
> > with the name returned by dwarf_decl_file(sp_die)
> >
> > The vmlinux file may have thousands of CUs.
> > We can lookup function name from .debug_pubnames section
> > to avoid the slow loop on CUs.
> >
> > ./perf stat -r 10 -- ./perf probe -k /home/mlin/vmlinux \
> > -s /home/mlin/linux-2.6 \
> > --line csum_partial_copy_to_user > tmp.log
> >
> > before patch applied
> > =====================
> > 364.535892 task-clock-msecs # 0.997 CPUs
> > 0 context-switches # 0.000 M/sec
> > 0 CPU-migrations # 0.000 M/sec
> > 29,993 page-faults # 0.082 M/sec
> > 865,862,109 cycles # 2375.245 M/sec
> > 1,255,259,630 instructions # 1.450 IPC
> > 252,400,884 branches # 692.390 M/sec
> > 3,429,376 branch-misses # 1.359 %
> > 1,386,990 cache-references # 3.805 M/sec
> > 687,188 cache-misses # 1.885 M/sec
> >
> > 0.365792170 seconds time elapsed
> >
> > after patch applied
> > =====================
> > 89.896405 task-clock-msecs # 0.991 CPUs
> > 1 context-switches # 0.000 M/sec
> > 0 CPU-migrations # 0.000 M/sec
> > 10,145 page-faults # 0.113 M/sec
> > 214,553,875 cycles # 2386.679 M/sec
> > 226,915,559 instructions # 1.058 IPC
> > 44,536,614 branches # 495.422 M/sec
> > 613,074 branch-misses # 1.377 %
> > 860,787 cache-references # 9.575 M/sec
> > 442,380 cache-misses # 4.921 M/sec
> >
> > 0.090716032 seconds time elapsed
>
> Thanks! Looks very good :)
>
> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Indeed, I'll try and process this one tomorrow,
Thanks a lot!
- Arnaldo
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