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From: Andi Kleen <ak@suse.de>
To: Bernd Paysan <bernd.paysan@gmx.de>
Cc: Andi Kleen <ak@suse.de>,
	suse-amd64@suse.com, linux-kernel@vger.kernel.org
Subject: Re: [suse-amd64] False "lost ticks" on dual-Opteron system (=> timer twice as fast)
Date: Tue, 10 May 2005 15:07:13 +0200	[thread overview]
Message-ID: <20050510130709.GI25612@wotan.suse.de> (raw)
In-Reply-To: <200505101355.00341.bernd.paysan@gmx.de>

On Tue, May 10, 2005 at 01:54:53PM +0200, Bernd Paysan wrote:
> On Tuesday 10 May 2005 13:12, Andi Kleen wrote:
> > > So that explains why nobody sees this problem. But the TSC-based
> > > fallback timekeeping is still broken on SMP systems with PowerNow and
> > > distributed IRQ handling, which both together seem to be rare enough
> > > ;-).
> >
> > There is a patch pending for the TSC problem - using the pmtimer instead
> > in this case.
> >
> > But the distributed timer interrupt problem is weird. It should not
> > happen. You sure it was IRQ 0 that was duplicated and not "LOC" ?
> 
> Yes. Only one CPU actually gets and handles the timer interrupt, but which 
> one is somewhat random (for about 10 seconds, it's the same CPU, then it 
> switches over).

That could be irqbalance doing its thing. Does it go away when
you stop it?

-Andi


  reply	other threads:[~2005-05-10 13:07 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-05-08 12:45 False "lost ticks" on dual-Opteron system (=> timer twice as fast) Bernd Paysan
2005-05-08 13:40 ` [suse-amd64] " Andi Kleen
2005-05-08 16:22   ` Bernd Paysan
2005-05-09 10:53   ` Bernd Paysan
2005-05-09 13:17     ` Bernd Paysan
2005-05-10 10:53       ` Ed Tomlinson
2005-05-10 13:32         ` Andi Kleen
2005-05-10 11:12       ` Andi Kleen
2005-05-10 11:36         ` Bernd Paysan
2005-05-10 11:54         ` Bernd Paysan
2005-05-10 13:07           ` Andi Kleen [this message]
2005-05-10 13:15             ` Bernd Paysan
2005-05-10 13:21               ` Andi Kleen
2005-05-10 13:39                 ` Arjan van de Ven
2005-05-21 19:42 ` Hendrik Visage
2005-05-21 20:54   ` Scott Robert Ladd
     [not found]   ` <428F9FA6.1000800@coyotegulch.com>
     [not found]     ` <d93f04c70505211500216d8614@mail.gmail.com>
2005-05-23 11:50       ` Scott Robert Ladd
2005-05-23 23:04         ` Hendrik Visage
2005-05-25 17:06           ` Andi Kleen

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