Re: [RFC][PATCH v2 5/7] taskstats: Improve cumulative CPU time accounting

From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>,
	Michael Holzheu <holzheu@linux.vnet.ibm.com>,
	Shailabh Nagar <nagar1234@in.ibm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Venkatesh Pallipadi <venki@google.com>,
	Suresh Siddha <suresh.b.siddha@intel.com>,
	Ingo Molnar <mingo@elte.hu>, John stultz <johnstul@us.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Balbir Singh <balbir@linux.vnet.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	Roland McGrath <roland@redhat.com>,
	linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org
Subject: Re: [RFC][PATCH v2 5/7] taskstats: Improve cumulative CPU time accounting
Date: Mon, 15 Nov 2010 19:00:31 +0100	[thread overview]
Message-ID: <20101115190031.5a50e760@mschwide.boeblingen.de.ibm.com> (raw)
In-Reply-To: <1289843517.2109.521.camel@laptop>

On Mon, 15 Nov 2010 18:51:57 +0100
Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:

> On Mon, 2010-11-15 at 18:49 +0100, Martin Schwidefsky wrote:
> > > To what purpose? 
> >  
> > Is that a trick question? Why do we have tools like "top"? Or process
> > accounting? The point is that the quality of the numbers we get right
> > now is rather bad, the overhead of scanning /proc is horrendous and
> > the 10ms granularity is rather coarse. 
> 
> But you're not just replacing top, you're adding all kinds of new
> accounting crap all over the place.

We DO replace top. Patch #7 of 7.

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.