Date: Mon, 8 Dec 2014 07:57:45 -0800
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Sasha Levin <sasha.levin@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Dave Jones <davej@redhat.com>, Chris Mason <clm@fb.com>,
        =?iso-8859-1?Q?D=E2niel?= Fraga <fragabr@gmail.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: frequent lockups in 3.18rc4
Message-ID: <20141208155745.GM25340@linux.vnet.ibm.com>
Reply-To: paulmck@linux.vnet.ibm.com
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On Mon, Dec 08, 2014 at 10:28:53AM -0500, Sasha Levin wrote:
> On 12/08/2014 09:33 AM, Sasha Levin wrote:
> > On 12/08/2014 12:20 AM, Paul E. McKenney wrote:
> >> > I have seen this caused by lost IPIs, but you have to lose two of them,
> >> > which seems less than fully likely.
> > It does seem that it can cause full blown stalls as well, just pretty
> > rarely (notice the lack of any prints before):
> 
> Forgot to mentioned, I cranked the rcu lockup timeout to 300 seconds and got
> that stall.

So with the default of 21 seconds, you presumably get huge numbers of
RCU CPU stall warnings?

							Thanx, Paul

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