From: Jens Axboe <jens.axboe-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
To: Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Cc: linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
npiggin-l3A5Bk7waGM@public.gmane.org,
torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org,
sam-uyr5N9Q2VtJg9hUCZPvPmw@public.gmane.org
Subject: Re: [PATCH 1/11] Add generic helpers for arch IPI function calls
Date: Wed, 23 Apr 2008 08:07:26 +0200 [thread overview]
Message-ID: <20080423060725.GT12774@kernel.dk> (raw)
In-Reply-To: <1208895423.7115.290.camel@twins>
On Tue, Apr 22 2008, Peter Zijlstra wrote:
> On Tue, 2008-04-22 at 20:50 +0200, Jens Axboe wrote:
>
> > +int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
> > + int retry, int wait)
> > +{
> > + unsigned long flags;
> > + /* prevent preemption and reschedule on another processor */
> > + int me = get_cpu();
> > +
> > + /* Can deadlock when called with interrupts disabled */
> > + WARN_ON(wait && irqs_disabled());
>
> With this fallback to wait the above condition isn't sufficient.
What deadlock are you concerned with here? Would making cfd_fallback
per-cpu make you feel better?
--
Jens Axboe
WARNING: multiple messages have this Message-ID (diff)
From: Jens Axboe <jens.axboe@oracle.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
npiggin@suse.de, torvalds@linux-foundation.org, sam@ravnborg.org
Subject: Re: [PATCH 1/11] Add generic helpers for arch IPI function calls
Date: Wed, 23 Apr 2008 08:07:26 +0200 [thread overview]
Message-ID: <20080423060725.GT12774@kernel.dk> (raw)
Message-ID: <20080423060726.4sQv_fbQfs_cRIs-hM3IBN4Tfsn4gIskYXy1kC_2Yws@z> (raw)
In-Reply-To: <1208895423.7115.290.camel@twins>
On Tue, Apr 22 2008, Peter Zijlstra wrote:
> On Tue, 2008-04-22 at 20:50 +0200, Jens Axboe wrote:
>
> > +int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
> > + int retry, int wait)
> > +{
> > + unsigned long flags;
> > + /* prevent preemption and reschedule on another processor */
> > + int me = get_cpu();
> > +
> > + /* Can deadlock when called with interrupts disabled */
> > + WARN_ON(wait && irqs_disabled());
>
> With this fallback to wait the above condition isn't sufficient.
What deadlock are you concerned with here? Would making cfd_fallback
per-cpu make you feel better?
--
Jens Axboe
next prev parent reply other threads:[~2008-04-23 6:07 UTC|newest]
Thread overview: 169+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-22 18:50 [PATCH 0/11] Generic smp_call_function() #2 Jens Axboe
2008-04-22 18:50 ` Jens Axboe
[not found] ` <1208890227-24808-1-git-send-email-jens.axboe-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2008-04-22 18:50 ` [PATCH 1/11] Add generic helpers for arch IPI function calls Jens Axboe
2008-04-22 18:50 ` Jens Axboe
[not found] ` <1208890227-24808-2-git-send-email-jens.axboe-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2008-04-22 20:17 ` Peter Zijlstra
2008-04-22 20:17 ` Peter Zijlstra
2008-04-23 6:07 ` Jens Axboe [this message]
2008-04-23 6:07 ` Jens Axboe
[not found] ` <20080423060725.GT12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-23 6:32 ` Peter Zijlstra
2008-04-23 6:32 ` Peter Zijlstra
2008-04-23 7:49 ` Jens Axboe
2008-04-23 7:49 ` Jens Axboe
[not found] ` <20080423074933.GB12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-23 7:50 ` Peter Zijlstra
2008-04-23 7:50 ` Peter Zijlstra
2008-04-24 22:01 ` Russell King
2008-04-24 22:01 ` Russell King
[not found] ` <20080424220157.GA26179-f404yB8NqCZvn6HldHNs0ANdhmdF6hFW@public.gmane.org>
2008-04-25 7:18 ` Jens Axboe
2008-04-25 7:18 ` Jens Axboe
[not found] ` <20080425071823.GF12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-26 6:28 ` Jeremy Fitzhardinge
2008-04-26 6:28 ` Jeremy Fitzhardinge
[not found] ` <4812CB99.1070600-TSDbQ3PG+2Y@public.gmane.org>
2008-04-28 7:38 ` Jes Sorensen
2008-04-28 7:38 ` Jes Sorensen
2008-04-26 6:11 ` Andrew Morton
2008-04-26 6:11 ` Andrew Morton
[not found] ` <20080425231100.b93a1601.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
2008-04-26 14:13 ` James Bottomley
2008-04-26 14:13 ` James Bottomley
2008-04-27 0:58 ` Paul E. McKenney
2008-04-27 0:58 ` Paul E. McKenney
[not found] ` <20080427005816.GB21687-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2008-04-27 10:36 ` Jens Axboe
2008-04-27 10:36 ` Jens Axboe
2008-04-27 10:30 ` Jens Axboe
2008-04-27 10:30 ` Jens Axboe
[not found] ` <1209219236.3113.6.camel-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2008-04-28 14:25 ` David Howells
2008-04-28 14:25 ` David Howells
[not found] ` <18470.1209392727-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2008-04-28 14:43 ` James Bottomley
2008-04-28 14:43 ` James Bottomley
2008-04-22 18:50 ` [PATCH 2/11] x86: convert to generic helpers for " Jens Axboe
2008-04-22 18:50 ` Jens Axboe
2008-04-22 19:03 ` Linus Torvalds
2008-04-22 19:03 ` Linus Torvalds
[not found] ` <alpine.LFD.1.10.0804221157220.2779-5CScLwifNT1QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
2008-04-22 19:12 ` Ingo Molnar
2008-04-22 19:12 ` Ingo Molnar
[not found] ` <20080422191213.GA6370-X9Un+BFzKDI@public.gmane.org>
2008-04-22 19:22 ` Linus Torvalds
2008-04-22 19:22 ` Linus Torvalds
2008-04-22 19:26 ` Ingo Molnar
2008-04-22 19:26 ` Ingo Molnar
[not found] ` <20080422192601.GB12588-X9Un+BFzKDI@public.gmane.org>
2008-04-22 19:50 ` Linus Torvalds
2008-04-22 19:50 ` Linus Torvalds
[not found] ` <alpine.LFD.1.10.0804221244350.2779-5CScLwifNT1QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
2008-04-23 1:11 ` Nick Piggin
2008-04-23 1:11 ` Nick Piggin
[not found] ` <20080423011153.GB17572-B4tOwbsTzaBolqkO4TVVkw@public.gmane.org>
2008-04-23 1:22 ` Linus Torvalds
2008-04-23 1:22 ` Linus Torvalds
[not found] ` <alpine.LFD.1.10.0804221817050.2779-5CScLwifNT1QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
2008-04-23 1:36 ` Nick Piggin
2008-04-23 1:36 ` Nick Piggin
2008-04-23 7:08 ` Jens Axboe
2008-04-23 7:08 ` Jens Axboe
2008-04-23 12:54 ` Jens Axboe
2008-04-23 12:54 ` Jens Axboe
[not found] ` <1208890227-24808-3-git-send-email-jens.axboe-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2008-04-26 6:44 ` Jeremy Fitzhardinge
2008-04-26 6:44 ` Jeremy Fitzhardinge
[not found] ` <4812CF5B.4080902-TSDbQ3PG+2Y@public.gmane.org>
2008-04-27 10:23 ` Jens Axboe
2008-04-27 10:23 ` Jens Axboe
[not found] ` <20080427102335.GS12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-27 15:18 ` Jeremy Fitzhardinge
2008-04-27 15:18 ` Jeremy Fitzhardinge
2008-04-22 18:50 ` [PATCH 3/11] powerpc: " Jens Axboe
2008-04-22 18:50 ` Jens Axboe
2008-04-22 18:50 ` [PATCH 4/11] ia64: " Jens Axboe
2008-04-22 18:50 ` Jens Axboe
2008-04-22 18:50 ` [PATCH 5/11] alpha: " Jens Axboe
2008-04-22 18:50 ` Jens Axboe
2008-04-22 18:50 ` [PATCH 6/11] arm: " Jens Axboe
2008-04-22 18:50 ` Jens Axboe
2008-04-22 18:50 ` [PATCH 7/11] m32r: " Jens Axboe
2008-04-22 18:50 ` Jens Axboe
2008-04-22 18:50 ` [PATCH 8/11] mips: " Jens Axboe
2008-04-22 18:50 ` Jens Axboe
2008-04-22 23:18 ` Ralf Baechle
2008-04-22 23:18 ` Ralf Baechle
2008-04-23 7:18 ` Jens Axboe
2008-04-23 7:18 ` Jens Axboe
2008-04-22 18:50 ` [PATCH 9/11] parisc: " Jens Axboe
2008-04-22 18:50 ` Jens Axboe
2008-04-22 18:50 ` [PATCH 10/11] sh: " Jens Axboe
2008-04-22 18:50 ` Jens Axboe
[not found] ` <1208890227-24808-11-git-send-email-jens.axboe-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2008-04-25 8:56 ` Paul Mundt
2008-04-25 8:56 ` Paul Mundt
[not found] ` <20080425085637.GA30569-M7jkjyW5wf5g9hUCZPvPmw@public.gmane.org>
2008-04-25 9:16 ` Jens Axboe
2008-04-25 9:16 ` Jens Axboe
2008-04-22 18:50 ` [PATCH 11/11] s390: " Jens Axboe
2008-04-22 18:50 ` Jens Axboe
[not found] ` <1208890227-24808-12-git-send-email-jens.axboe-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2008-04-23 7:58 ` Heiko Carstens
2008-04-23 7:58 ` Heiko Carstens
[not found] ` <20080423075831.GB15850-Pmgahw53EmNLmI7Nx2oIsGnsbthNF6/HVpNB7YpNyf8@public.gmane.org>
2008-04-23 8:11 ` Jens Axboe
2008-04-23 8:11 ` Jens Axboe
[not found] ` <20080423081147.GC12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-23 11:21 ` Jens Axboe
2008-04-23 11:21 ` Jens Axboe
[not found] ` <20080423112124.GJ12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-23 11:47 ` Heiko Carstens
2008-04-23 11:47 ` Heiko Carstens
[not found] ` <20080423114744.GA29422-Pmgahw53EmNLmI7Nx2oIsGnsbthNF6/HVpNB7YpNyf8@public.gmane.org>
2008-04-23 11:54 ` Jens Axboe
2008-04-23 11:54 ` Jens Axboe
2008-04-23 12:42 ` Martin Schwidefsky
2008-04-23 12:42 ` Martin Schwidefsky
2008-04-23 15:56 ` Rusty Russell
2008-04-23 15:56 ` Rusty Russell
-- strict thread matches above, loose matches on Subject: below --
2008-04-22 7:57 [PATCH 0/11] Generic smp_call_function() and friends Jens Axboe
[not found] ` <1208851058-8500-1-git-send-email-jens.axboe-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2008-04-22 7:57 ` [PATCH 1/11] Add generic helpers for arch IPI function calls Jens Axboe
2008-04-22 7:57 ` Jens Axboe
[not found] ` <1208851058-8500-2-git-send-email-jens.axboe-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
2008-04-22 9:16 ` Avi Kivity
2008-04-22 9:16 ` Avi Kivity
[not found] ` <480DACDD.7040108-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2008-04-22 9:22 ` Jens Axboe
2008-04-22 9:22 ` Jens Axboe
[not found] ` <20080422092230.GW12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-22 11:14 ` Jens Axboe
2008-04-22 11:14 ` Jens Axboe
2008-04-22 13:00 ` Peter Zijlstra
2008-04-22 13:00 ` Peter Zijlstra
2008-04-22 14:25 ` Jens Axboe
2008-04-22 14:25 ` Jens Axboe
[not found] ` <20080422142543.GG12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-22 14:38 ` Avi Kivity
2008-04-22 14:38 ` Avi Kivity
[not found] ` <480DF861.6000705-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2008-04-22 14:43 ` Peter Zijlstra
2008-04-22 14:43 ` Peter Zijlstra
2008-04-22 14:47 ` Avi Kivity
2008-04-22 14:47 ` Avi Kivity
2008-04-22 14:53 ` Jens Axboe
2008-04-22 14:53 ` Jens Axboe
2008-04-22 14:43 ` Linus Torvalds
2008-04-22 14:43 ` Linus Torvalds
[not found] ` <alpine.LFD.1.10.0804220735350.2779-5CScLwifNT1QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
2008-04-22 14:51 ` Jens Axboe
2008-04-22 14:51 ` Jens Axboe
2008-04-22 15:01 ` Linus Torvalds
2008-04-22 15:01 ` Linus Torvalds
2008-04-22 16:49 ` Jens Axboe
2008-04-22 16:49 ` Jens Axboe
[not found] ` <20080422164947.GN12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-22 17:04 ` Jens Axboe
2008-04-22 17:04 ` Jens Axboe
[not found] ` <20080422170405.GO12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-22 17:13 ` Jens Axboe
2008-04-22 17:13 ` Jens Axboe
[not found] ` <20080422171324.GP12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-22 17:29 ` Linus Torvalds
2008-04-22 17:29 ` Linus Torvalds
[not found] ` <alpine.LFD.1.10.0804221027210.2779-5CScLwifNT1QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
2008-04-22 18:23 ` Jens Axboe
2008-04-22 18:23 ` Jens Axboe
[not found] ` <20080422182337.GQ12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-22 18:39 ` Linus Torvalds
2008-04-22 18:39 ` Linus Torvalds
2008-04-22 14:58 ` Linus Torvalds
2008-04-22 14:58 ` Linus Torvalds
[not found] ` <alpine.LFD.1.10.0804220749450.2779-5CScLwifNT1QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
2008-04-22 15:07 ` Jens Axboe
2008-04-22 15:07 ` Jens Axboe
2008-04-22 23:12 ` Mark Lord
2008-04-22 23:12 ` Mark Lord
[not found] ` <480E70ED.3030701-gsilrlXbHYg@public.gmane.org>
2008-04-23 7:24 ` Jens Axboe
2008-04-23 7:24 ` Jens Axboe
[not found] ` <20080423072432.GX12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-23 13:42 ` Mark Lord
2008-04-23 13:42 ` Mark Lord
[not found] ` <480F3CBC.60305-gsilrlXbHYg@public.gmane.org>
2008-04-23 13:51 ` Jens Axboe
2008-04-23 13:51 ` Jens Axboe
2008-04-23 14:46 ` Mark Lord
2008-04-23 14:46 ` Mark Lord
[not found] ` <480F4BD9.8090003-gsilrlXbHYg@public.gmane.org>
2008-04-24 10:59 ` Jens Axboe
2008-04-24 10:59 ` Jens Axboe
[not found] ` <20080424105908.GW12774-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2008-04-24 12:44 ` Mark Lord
2008-04-24 12:44 ` Mark Lord
[not found] ` <481080A0.9050804-gsilrlXbHYg@public.gmane.org>
2008-04-24 21:30 ` Rafael J. Wysocki
2008-04-24 21:30 ` Rafael J. Wysocki
2008-04-25 11:08 ` Pavel Machek
2008-04-25 11:08 ` Pavel Machek
2008-04-26 8:04 ` Pavel Machek
2008-04-26 8:04 ` Pavel Machek
2008-04-28 15:13 ` Mark Lord
2008-04-28 15:13 ` Mark Lord
2008-05-01 16:23 ` Pavel Machek
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