From: Don Zickus <dzickus@redhat.com>
To: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Robert Richter <robert.richter@amd.com>,
Lin Ming <ming.m.lin@intel.com>, Ingo Molnar <mingo@elte.hu>,
"fweisbec@gmail.com" <fweisbec@gmail.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Huang, Ying" <ying.huang@intel.com>,
Yinghai Lu <yinghai@kernel.org>
Subject: Re: A question of perf NMI handler
Date: Wed, 4 Aug 2010 12:20:26 -0400 [thread overview]
Message-ID: <20100804162026.GU3353@redhat.com> (raw)
In-Reply-To: <20100804161046.GC5130@lenovo>
On Wed, Aug 04, 2010 at 08:10:46PM +0400, Cyrill Gorcunov wrote:
> On Wed, Aug 04, 2010 at 11:50:02AM -0400, Don Zickus wrote:
> ...
> > >
> > > Well, first I guess having Yinghai CC'ed is a bonus ;)
> > > The second thing is that I don't get why perf handler can't be _last_
> > > call in default_do_nmi, if there were any nmi with reason (serr or parity)
> > > I think they should be calling first which of course don't eliminate
> > > the former issue but somewhat make it weaken.
> >
> > Because the reason registers are never set. If they were, then the code
> > wouldn't have to walk the notify_chain. :-)
> >
>
> maybe we're talking about different things. i meant that if there is nmi
> with a reason (from 0x61) the handling of such nmi should be done before
> notify_die I think (if only I not miss something behind).
No we are talking about the same thing. :-) And that code is already
there. The problem is the bits in register 0x61 are not always set
correctly in the case of SERRs (well at least in all the cases I have
dealt with). So you can easily can a flood of unknown nmis from an SERR
and register 0x61 would have the PERR/SERR bits set to 0. Fun, huh?
Cheers,
Don
next prev parent reply other threads:[~2010-08-04 16:20 UTC|newest]
Thread overview: 85+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-04 9:21 A question of perf NMI handler Lin Ming
2010-08-04 9:50 ` Peter Zijlstra
2010-08-04 10:01 ` Robert Richter
2010-08-04 10:24 ` Peter Zijlstra
2010-08-04 10:29 ` Robert Richter
2010-08-04 14:00 ` Don Zickus
2010-08-04 14:11 ` Peter Zijlstra
2010-08-04 14:52 ` Don Zickus
2010-08-04 15:02 ` Peter Zijlstra
2010-08-04 15:18 ` Cyrill Gorcunov
2010-08-04 15:50 ` Don Zickus
2010-08-04 16:10 ` Cyrill Gorcunov
2010-08-04 16:20 ` Don Zickus [this message]
2010-08-04 16:39 ` Cyrill Gorcunov
2010-08-04 18:48 ` Robert Richter
2010-08-04 19:22 ` Andi Kleen
2010-08-04 19:26 ` Cyrill Gorcunov
2010-08-06 6:52 ` Robert Richter
2010-08-06 14:21 ` Don Zickus
2010-08-09 19:48 ` [PATCH] perf, x86: try to handle unknown nmis with running perfctrs Robert Richter
2010-08-09 20:02 ` Cyrill Gorcunov
2010-08-10 7:42 ` Robert Richter
2010-08-10 16:16 ` Cyrill Gorcunov
2010-08-10 16:41 ` Robert Richter
2010-08-10 17:24 ` Cyrill Gorcunov
2010-08-10 19:05 ` Robert Richter
2010-08-10 19:24 ` Cyrill Gorcunov
2010-08-12 13:24 ` Robert Richter
2010-08-12 14:31 ` Cyrill Gorcunov
2010-08-10 20:48 ` Don Zickus
2010-08-11 2:44 ` Frederic Weisbecker
2010-08-11 11:10 ` Robert Richter
2010-08-11 12:44 ` Don Zickus
2010-08-11 14:03 ` Robert Richter
2010-08-11 14:32 ` Don Zickus
2010-08-13 4:37 ` Frederic Weisbecker
2010-08-13 8:22 ` Robert Richter
2010-08-14 1:28 ` Frederic Weisbecker
2010-08-14 2:29 ` Robert Richter
2010-08-11 12:39 ` Don Zickus
2010-08-11 3:19 ` Huang Ying
2010-08-11 12:36 ` Don Zickus
2010-08-16 14:37 ` Peter Zijlstra
2010-08-11 22:00 ` [PATCH -v2] " Robert Richter
2010-08-12 13:10 ` Robert Richter
2010-08-12 18:21 ` Don Zickus
2010-08-16 7:37 ` Robert Richter
2010-08-12 13:52 ` Don Zickus
2010-08-13 4:25 ` Frederic Weisbecker
2010-08-16 14:48 ` Peter Zijlstra
2010-08-16 16:27 ` Cyrill Gorcunov
2010-08-16 17:16 ` Robert Richter
2010-08-16 19:06 ` Cyrill Gorcunov
2010-08-16 19:13 ` Peter Zijlstra
2010-08-16 19:18 ` Cyrill Gorcunov
2010-08-16 22:55 ` Robert Richter
2010-08-17 15:23 ` Cyrill Gorcunov
2010-08-17 15:22 ` [PATCH -v3] " Robert Richter
2010-08-17 16:17 ` Cyrill Gorcunov
2010-08-19 10:45 ` Peter Zijlstra
2010-08-19 12:39 ` Robert Richter
2010-08-19 14:12 ` Don Zickus
2010-08-19 14:27 ` Peter Zijlstra
2010-08-19 15:20 ` Don Zickus
2010-08-19 17:43 ` Cyrill Gorcunov
2010-08-19 17:53 ` Peter Zijlstra
2010-08-19 21:58 ` Don Zickus
2010-08-20 8:50 ` Peter Zijlstra
2010-08-20 1:50 ` Don Zickus
2010-08-20 8:16 ` Ingo Molnar
2010-08-20 10:04 ` Peter Zijlstra
2010-08-20 10:30 ` Cyrill Gorcunov
2010-08-20 12:39 ` Don Zickus
2010-08-20 13:27 ` Ingo Molnar
2010-08-20 13:51 ` Don Zickus
2010-08-20 14:17 ` Ingo Molnar
2010-08-20 20:45 ` Cyrill Gorcunov
2010-08-24 21:48 ` Don Zickus
2010-08-20 8:36 ` Robert Richter
2010-08-20 14:17 ` [tip:perf/urgent] perf, x86: Fix handle_irq return values tip-bot for Peter Zijlstra
2010-08-20 14:17 ` [tip:perf/urgent] perf, x86: Try to handle unknown nmis with an enabled PMU tip-bot for Robert Richter
2010-08-06 15:35 ` A question of perf NMI handler Andi Kleen
2010-08-04 15:45 ` Don Zickus
2010-08-06 15:37 ` Andi Kleen
2010-08-04 13:54 ` Don Zickus
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