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From: Chris Friesen <chris.friesen@genband.com>
To: Ingo Molnar <mingo@elte.hu>,
	Peter Zijlstra <peterz@infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: RFC: /proc/<pid>/sched should contain cumulative data for all threads in process
Date: Mon, 07 Feb 2011 16:29:15 -0600	[thread overview]
Message-ID: <4D50723B.7020400@genband.com> (raw)


Hi,

We've got a tool that gathers lots of scheduling data for each process
(not task/thread) on the system.

For /proc/<pid>/{stat,io} this is straightforward, as the per-thread
values are summed together for the process as a whole.

However, /proc/<pid>/sched only shows the data for the individual thread
with the same tid as the pid.  To get a per-process view we need to
manually scan all the threads and sum them--and this can get expensive
due to all the extra file operations, parsing, etc.

Was this a concious design decision, or just an oversight?  Would a
patch converting it to whole-process values be accepted or is it enough
of a standard interface that we can't break existing apps that expect
the current behaviour?

Thanks,
Chris

-- 
Chris Friesen
Software Developer
GENBAND
chris.friesen@genband.com
www.genband.com

             reply	other threads:[~2011-02-07 22:31 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-07 22:29 Chris Friesen [this message]
2011-02-08  9:21 ` RFC: /proc/<pid>/sched should contain cumulative data for all threads in process Peter Zijlstra
2011-02-08 12:11   ` Ingo Molnar
2011-02-08 13:45     ` Peter Zijlstra
2011-02-08 15:14       ` Ingo Molnar
2011-02-09 17:28       ` Chris Friesen

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