From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Mike Galbraith <mgalbraith@novell.com>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: Re: rcu: endless stalls
Date: Mon, 11 Jun 2012 09:54:13 -0700 [thread overview]
Message-ID: <20120611165413.GC2521@linux.vnet.ibm.com> (raw)
In-Reply-To: <1339424543.7350.101.camel@marge.simpson.net>
On Mon, Jun 11, 2012 at 04:22:23PM +0200, Mike Galbraith wrote:
> On Mon, 2012-06-11 at 06:39 -0700, Paul E. McKenney wrote:
> > On Mon, Jun 11, 2012 at 12:06:16PM +0200, Mike Galbraith wrote:
> > > Greetings,
> > >
> > > I received a report of a 48 core UV box hitting a gripe, taking longer
> > > than timeout to emit same, so box griped endlessly, forcing reboot.
> >
> > So it took minutes to print an RCU CPU stall warning? On only 48 CPUs?
> >
> > If so, yow!!!
>
> The report was a tad fuzzy on details, but serial console can take a
> while at low baud rate, and the box was apparently perma-stalled.
Which clearly demands the question "why not increase the serial-console
baud rate"... ;-)
Thanx, Paul
> > My guess is that rcu_cpu_stall_suppress must be manipulated atomically
> > for this to work reliably, for example, using xchg().
>
> Ah, thanks.
>
> -Mike
>
next prev parent reply other threads:[~2012-06-11 16:55 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-11 10:06 rcu: endless stalls Mike Galbraith
2012-06-11 13:39 ` Paul E. McKenney
2012-06-11 14:22 ` Mike Galbraith
2012-06-11 16:54 ` Paul E. McKenney [this message]
2012-06-11 17:20 ` Mike Galbraith
2012-06-11 18:01 ` Paul E. McKenney
2012-06-11 18:10 ` Mike Galbraith
2012-06-13 3:35 ` Mike Galbraith
2012-06-13 4:31 ` Hugh Dickins
2012-06-13 5:56 ` Mike Galbraith
2012-06-13 7:12 ` Mike Galbraith
2012-06-14 7:45 ` Mike Galbraith
2012-06-14 16:47 ` Paul E. McKenney
2012-06-14 21:34 ` Mike Galbraith
2012-06-15 7:49 ` Mike Galbraith
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