From mboxrd@z Thu Jan  1 00:00:00 1970
From: Namhyung Kim <namhyung@kernel.org>
Subject: Re: attr inherit vs inherit_stat
Date: Tue, 04 Sep 2012 15:55:15 +0900
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In-Reply-To: <alpine.DEB.2.00.1208071544240.16260@cl320.icl.utk.edu> (Vince
	Weaver's message of "Tue, 7 Aug 2012 15:47:32 -0400")
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To: Vince Weaver <vweaver1@eecs.utk.edu>
Cc: linux-perf-users@vger.kernel.org

On Tue, 7 Aug 2012 15:47:32 -0400, Vince Weaver wrote:
> Hello

Hello Vince,

>
> I'm trying to figure out the difference between the "inherit" and
> "inherit_stat" bitfields in the perf_event_attr structure.
>
> Both seem to have similar functionality, and the code in core.c
> is hard to follow.
>
> Does anyone have any idea?

AFAIK the "inherit" field determines whether the event is inherited to a
child process/thread.  The "inherit_stat" is only meaningful when the
"inherit" field is also set and it'll preserve (saved) event counts
between context switch of the inherited processes/threads.

Thanks,
Namhyung