Messages in this thread | | | Date | Tue, 12 Nov 2013 18:48:25 -0800 | From | Sukadev Bhattiprolu <> | Subject | Re: [PATCH V3 06/11] perf record: Add an option to force per-cpu mmaps |
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Ingo Molnar [mingo@kernel.org] wrote: | | * Peter Zijlstra <peterz@infradead.org> wrote: | | > On Tue, Nov 05, 2013 at 02:31:52PM -0300, Arnaldo Carvalho de Melo wrote: | > > PeterZ, | > > | > > Can I have your Acked-by for this one? I guess now the goal is | > > achieved, no?
Being able to profile children with the --pid is a big plus.
| > | > So this option allows -t/-p/-u to create one buffer per cpu and attach | > all the various thread/process/user tasks' their counters to that one | > buffer? | > | > As opposed to the current state where each such counter would have its | > own buffer. | > | > If this is what the patch does, then yes, although I would prefer a | > slightly clearer Changelog. | > | > Acked-by: Peter Zijlstra <peterz@infradead.org> | | Is there any reason why we wouldn't want to make this the default | behavior? | | That way we could also lose the somewhat suboptimal 'force' naming: | there's nothing forced really, we simply switch to another ring-buffer | setup ...
It would be also good if the man page added a comment on when a user would want one ring-buffer setup over the other.
If the main benefit is to have the children profiled when tasks are specified, how about changing the option to --inherit (-I) ?
Or for consistency with 'perf record <application>', have --pid profile children by default and let users specify --no-inherit with --pid if they don't want children profiled.
Sukadev
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