Re: [RFC/PATCH] perf record: Save build-id of DSO in callchains

[David Ahern]

On 3/23/15 2:18 AM, Namhyung Kim wrote:
> > Just curious, could you try to measure the performance impact of this
> > change?
>
>    $ time perf record --call-graph dwarf -o kbuild.xxx -a -- sleep 30
>    [ perf record: Woken up 34674 times to write data ]
>    [ perf record: Captured and wrote 9538.729 MB kbuild.xxx (1211997 samples) ]
>
>    real   0m32.244s
>    user   0m1.097s
>    sys    0m8.997s
>
>    $ time perf record --call-graph dwarf -o kbuild.yyy --buildid-callchain -a -- sleep 30
>    [ perf record: Woken up 40902 times to write data ]
>    [ perf record: Captured and wrote 11208.500 MB kbuild.yyy (1433922 samples) ]
>
>    real   2m21.695s
>    user   1m33.127s
>    sys    0m22.077s

How many CPUs and processes?

David

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