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From: Dave Jones <davej@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	Tejun Heo <tj@kernel.org>
Subject: Re: excessive kworker activity when idle. (was Re: vma corruption in today's -git)
Date: Thu, 31 Mar 2011 11:49:42 -0400	[thread overview]
Message-ID: <20110331154941.GA32045@redhat.com> (raw)
In-Reply-To: <AANLkTimAGbzYe7PNG1xhjsA12zErpRasTso711cq8UHq@mail.gmail.com>

On Thu, Mar 31, 2011 at 08:25:36AM -0700, Linus Torvalds wrote:
 > On Thu, Mar 31, 2011 at 8:03 AM, Dave Jones <davej@redhat.com> wrote:
 > > On Thu, Mar 31, 2011 at 10:58:50AM -0400, Dave Jones wrote:
 > >
 > > bah I missed a level. which seems to be the smoking gun.
 > > something in the tty layer seems to have gone nuts.
 > 
 > Ahhah. That is indeed the smoking gun.
 > 
 > I bet it's an old problem where something causes some stupid tty
 > ping-pong behaviour, and now it has become a high-CPU thing triggered
 > by commit f23eb2b2b285 ("tty: stop using "delayed_work" in the tty
 > layer").
 > 
 > Before that commit, if the tty layer got somehow confused, it would
 > always delay for a timer tick in between doing nothing. Now it will go
 > pretty much full blast. Which explains your CPU being hot.

That's a recent change though, and I first saw this back in November.

	Dave


  reply	other threads:[~2011-03-31 15:50 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-29  4:09 vma corruption in today's -git Dave Jones
2011-03-29  4:19 ` Américo Wang
2011-03-29  4:26   ` Dave Jones
2011-03-29  4:22 ` Linus Torvalds
2011-03-31  3:09   ` excessive kworker activity when idle. (was Re: vma corruption in today's -git) Dave Jones
2011-03-31  3:34     ` Dave Jones
2011-03-31  3:44       ` Linus Torvalds
2011-03-31  4:08         ` Dave Jones
2011-03-31 15:53           ` Linus Torvalds
2011-03-31 16:21             ` Linus Torvalds
2011-03-31 21:38               ` Linus Torvalds
2011-03-31 14:59         ` Paul E. McKenney
2011-03-31  3:37     ` Linus Torvalds
2011-03-31  3:55       ` Dave Jones
2011-03-31  5:32         ` Linus Torvalds
2011-03-31 14:21           ` Arnaldo Carvalho de Melo
2011-03-31 14:58           ` Dave Jones
2011-03-31 15:03             ` Dave Jones
2011-03-31 15:09               ` Dave Jones
2011-03-31 15:45                 ` Linus Torvalds
2011-03-31 15:25               ` Linus Torvalds
2011-03-31 15:49                 ` Dave Jones [this message]
2011-03-31 15:58                   ` Linus Torvalds
2011-03-31 16:13                     ` Dave Jones
2011-03-31  6:56       ` Tejun Heo
2011-03-31 10:37         ` [PATCH] workqueue: document debugging tricks Florian Mickler
2011-03-31 11:41           ` Tejun Heo

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