From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: kosaki.motohiro@jp.fujitsu.com, balbir@linux.vnet.ibm.com,
LKML <linux-kernel@vger.kernel.org>,
Bharata B Rao <bharata@linux.vnet.ibm.com>,
Balaji Rao <balajirrao@gmail.com>,
Dhaval Giani <dhaval@linux.vnet.ibm.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Ingo Molnar <mingo@elte.hu>,
Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [PATCH v2] cpuacct: VIRT_CPU_ACCOUNTING don't prevent percpu cputime count
Date: Thu, 30 Apr 2009 17:52:16 +0900 (JST) [thread overview]
Message-ID: <20090430175112.D225.A69D9226@jp.fujitsu.com> (raw)
In-Reply-To: <1241081240.4756.38.camel@laptop>
> > > for (i = 0; i < CPUACCT_STAT_NSTATS; i++) {
> > > - s64 val = percpu_counter_read(&ca->cpustat[i]);
> > > + s64 val = percpu_counter_sum(&ca->cpustat[i]);
> > > val = cputime64_to_clock_t(val);
> > > cb->fill(cb, cpuacct_stat_desc[i], val);
> > > }
> >
> > What do the test results look like with this? I'll see if I can find
> > some time to test this patch. On a patch read level this seems much better
> > to me, Peter?
>
> I don't really fancy percpu_counter_sum() usage. I'm thinking its ok to
> degrate accuracy on larger machines and simply use
> percpu_counter_read().
I have same opinion with peter. Balbir, What do you think?
next prev parent reply other threads:[~2009-04-30 8:52 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-30 6:11 KOSAKI Motohiro
2009-04-30 6:18 ` Balbir Singh
2009-04-30 8:28 ` KOSAKI Motohiro
2009-04-30 8:47 ` Peter Zijlstra
2009-04-30 8:52 ` KOSAKI Motohiro [this message]
2009-04-30 9:02 ` Balbir Singh
2009-04-30 8:55 ` Ingo Molnar
2009-05-01 1:10 ` Andrew Morton
2009-05-01 1:45 ` KOSAKI Motohiro
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