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From: Suresh Siddha <suresh.b.siddha@intel.com>
To: "paulmck@linux.vnet.ibm.com" <paulmck@linux.vnet.ibm.com>
Cc: Nick Piggin <npiggin@suse.de>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Oleg Nesterov <oleg@redhat.com>,
	Jens Axboe <jens.axboe@oracle.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Ingo Molnar <mingo@elte.hu>,
	Rusty Russell <rusty@rustcorp.com.au>,
	Steven Rostedt <rostedt@goodmis.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Subject: Re: smp.c && barriers (Was: [PATCH 1/4] generic-smp: remove	single ipi fallback for smp_call_function_many())
Date: Tue, 17 Feb 2009 18:15:31 -0800	[thread overview]
Message-ID: <1234923331.29823.2.camel@vayu> (raw)
In-Reply-To: <20090217155147.GE6761@linux.vnet.ibm.com>

On Tue, 2009-02-17 at 07:51 -0800, Paul E. McKenney wrote:
> On Tue, Feb 17, 2009 at 12:26:57PM +0100, Nick Piggin wrote:
> > +	spin_lock(&q->lock);
> > +	list_replace_init(&q->list, &list);
> > +	spin_unlock(&q->lock);
> 
> OK, I'll bite...
> 
> How do we avoid deadlock in the case where a pair of CPUs send to each
> other concurrently?

Sender takes the lock with interrupts-disabled. That should prevent any
deadlock, right?

  reply	other threads:[~2009-02-18  2:16 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20090216204902.GA6924@redhat.com>
     [not found] ` <1234818201.30178.386.camel@laptop>
     [not found]   ` <20090216213205.GA9098@redhat.com>
     [not found]     ` <1234820704.30178.396.camel@laptop>
     [not found]       ` <20090216220214.GA10093@redhat.com>
     [not found]         ` <1234823097.30178.406.camel@laptop>
     [not found]           ` <20090216231946.GA12009@redhat.com>
     [not found]             ` <1234862974.4744.31.camel@laptop>
     [not found]               ` <20090217101130.GA8660@wotan.suse.de>
     [not found]                 ` <1234866453.4744.58.camel@laptop>
2009-02-17 11:26                   ` Q: smp.c && barriers (Was: [PATCH 1/4] generic-smp: remove single ipi fallback for smp_call_function_many()) Nick Piggin
2009-02-17 11:48                     ` Peter Zijlstra
2009-02-17 15:51                     ` Paul E. McKenney
2009-02-18  2:15                       ` Suresh Siddha [this message]
2009-02-18  2:40                         ` Paul E. McKenney
2009-02-17 19:28                     ` Q: " Oleg Nesterov
2009-02-17 21:32                       ` Paul E. McKenney
2009-02-17 21:45                         ` Oleg Nesterov
2009-02-17 22:39                           ` Paul E. McKenney
2009-02-18 13:52                             ` Nick Piggin
2009-02-18 16:09                               ` Linus Torvalds
2009-02-18 16:21                                 ` Ingo Molnar
2009-02-18 16:21                                   ` Ingo Molnar
2009-02-18 16:33                                   ` Linus Torvalds
2009-02-18 16:58                                     ` Ingo Molnar
2009-02-18 17:05                                       ` Ingo Molnar
2009-02-18 17:10                                         ` Ingo Molnar
2009-02-18 17:17                                           ` Linus Torvalds
2009-02-18 17:23                                             ` Ingo Molnar
2009-02-18 17:14                                         ` Linus Torvalds
2009-02-18 17:47                                           ` Ingo Molnar
2009-02-18 18:33                                           ` Suresh Siddha
2009-02-18 16:37                                   ` Gleb Natapov
2009-02-19  0:12                                 ` Nick Piggin
2009-02-19  6:47                                 ` Benjamin Herrenschmidt
2009-02-19 13:11                                   ` Nick Piggin
2009-02-19 13:11                                     ` Nick Piggin
2009-02-19 15:06                                     ` Ingo Molnar
2009-02-19 21:49                                       ` Benjamin Herrenschmidt
2009-02-18  2:21                     ` Suresh Siddha
2009-02-18 13:59                       ` Nick Piggin
2009-02-18 16:19                         ` Linus Torvalds
2009-02-18 16:23                           ` Ingo Molnar
2009-02-18 18:43                         ` Suresh Siddha
2009-02-18 19:17                           ` Ingo Molnar
2009-02-18 23:55                             ` Suresh Siddha
2009-02-19 12:20                               ` Ingo Molnar
2009-02-19 12:29                                 ` Nick Piggin
2009-02-19 12:45                                   ` Ingo Molnar
2009-02-19 22:00                                 ` Suresh Siddha
2009-02-20 10:56                                   ` Ingo Molnar
2009-02-20 18:56                                     ` Suresh Siddha
2009-02-20 18:56                                       ` Suresh Siddha
2009-02-20 19:40                                       ` Ingo Molnar
2009-02-20 23:28                                       ` Jack Steiner
2009-02-25  3:32                                       ` Nick Piggin
2009-02-25 12:47                                         ` Ingo Molnar
2009-02-25 18:25                                         ` Luck, Tony
2009-03-17 18:16                                         ` Suresh Siddha

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