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From: Oleg Nesterov <oleg@redhat.com>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jaromir Capik <jcapik@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Michal Hocko <mhocko@suse.cz>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ania Honess <ahoness@redhat.com>,
	atomlin@redhat.com, asolanas@redhat.com,
	linux-kernel@vger.kernel.org
Subject: Re: proc/stat: idle goes backward
Date: Fri, 16 Aug 2013 17:13:39 +0200	[thread overview]
Message-ID: <20130816151339.GA29675@redhat.com> (raw)
In-Reply-To: <20130816150122.GB24210@somewhere>

On 08/16, Frederic Weisbecker wrote:
>
> On Fri, Aug 16, 2013 at 04:47:04PM +0200, Oleg Nesterov wrote:
> >
> > Questions:
> >
> > 	- Any other reason why it can be non-monotonic?
> >
> > 	- Should we fix this or should we document that userspace
> > 	  should handle this itself?
> >
> > 	  IOW, is this is bug or not?
>
> I don't know if we want to fix it (I personally think we should because it is not the
> first time I hear complains about this) but if we do, here is a possible fix:
>
> https://lkml.org/lkml/2013/8/8/638

Thanks! it is not easy to read the patches on lkml.org and I do
not understand this code enough. But it seems that this should
address my concerns, including the "even ignoring drivers/cpuidle/".

Except, I am not sure that these changes handle the case when
nr_iowait() change in between.

Are you going to resend?

Oleg.


  reply	other threads:[~2013-08-16 15:19 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <v5wUE000000000000000000000000000000000000000000000MRITO500uRRuI-89T-iqXCkOVGWF4w@sfdc.net>
     [not found] ` <1904614521.2884383.1376487067689.JavaMail.root@redhat.com>
     [not found]   ` <1277145964.2082352.1376490809716.JavaMail.root@redhat.com>
2013-08-16 14:47     ` proc/stat: idle goes backward Oleg Nesterov
2013-08-16 15:01       ` Frederic Weisbecker
2013-08-16 15:13         ` Oleg Nesterov [this message]
2013-08-16 15:30           ` Frederic Weisbecker

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