Re: [PATCH V2] perf: Speed up thread map generation

From: Jiri Olsa
Date: Fri Mar 14 2014 - 12:12:22 EST


On Fri, Mar 14, 2014 at 10:43:44AM -0400, Don Zickus wrote:
> When trying to capture perf data on a system running spejbb2013,
> perf hung for about 15 minutes. This is because it took that
> long to gather about 10,000 thread maps and process them.
>
> I don't think a user wants to wait that long.
>
> Instead, recognize that thread maps are roughly equivalent to
> pid maps and just quickly copy those instead.
>
> To do this, I synthesize 'fork' events, this eventually calls
> thread__fork() and copies the maps over.
>
> The overhead goes from 15 minutes down to about a few seconds.
>
> Signed-off-by: Don Zickus <dzickus@xxxxxxxxxx>
> --
> V2: based on Jiri's comments, moved malloc up a level
> and made sure the memory was freed

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

thanks,
jirka
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