Re: [PATCH v4 2/3] Support for perf to probe into SDT markers:

From: Masami Hiramatsu
Date: Wed Oct 30 2013 - 06:22:47 EST


(2013/10/29 3:45), Pekka Enberg wrote:
> On 10/28/13 6:59 PM, David Ahern wrote:
> > I often use perf-list to lookup an exact event name, and I do not want
> > to see it taking many seconds to minutes to run (not everyone is
> > running on an SSD). I also run perf on many different OS versions with
> > an NFS home directory, and do not want to see a cache explosion (I
> > have buildid disabled for this reason).
>
> I am talking about reasonable defaults - the 'default' part implies that
> people can change the behavior. So we absolutely should also have
> something like this for power users such as yourself:
>
> perf config sdt.scan false

Ah, I like this perf-config to store the default/customized values ;)

> That said, the 'reasonable' part suggests that 'perf list' must not take
> seconds or minutes (!) for every run. I'd start with implementing a
> naive scan and seeing where it takes us. It's not like it's rocket
> science to ignore network mounts or revert to a whitelist of paths if
> necessary.

I think it is reasonable to scan only $PATH and ld.so.cache (the result
of ldconfig --print-cache) by default. :)

Thank you,



--
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx


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