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Subject: Re: [RFC][PATCH v2 5/7] taskstats: Improve cumulative CPU time
 accounting
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
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Date: Mon, 15 Nov 2010 18:51:57 +0100
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To: Martin Schwidefsky <schwidefsky@de.ibm.com>
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
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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.