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From: Peter Zijlstra <peterz@infradead.org>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Andi Kleen <andi@firstfloor.org>,
	Huang Ying <ying.huang@intel.com>, Ingo Molnar <mingo@elte.hu>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: x86: Inconsistent xAPIC synchronization in arch_irq_work_raise?
Date: Thu, 23 Jan 2014 20:11:40 +0100	[thread overview]
Message-ID: <20140123191140.GV11314@laptop.programming.kicks-ass.net> (raw)
In-Reply-To: <52E164BC.1080302@siemens.com>

On Thu, Jan 23, 2014 at 07:51:40PM +0100, Jan Kiszka wrote:
> Next we have x86's arch_irq_work_raise which does wait-write-wait,
> either by chance or in order to work around a missing atomicity of
> wait+write somewhere else. Preemption is off, interrupts remain on.

Note that arch_irq_work_raise() is 'special' in that its used from NMI
context, so no amount of interrupts disabling will serialize things.

  reply	other threads:[~2014-01-23 19:12 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-21 13:02 Jan Kiszka
2014-01-21 14:01 ` Peter Zijlstra
2014-01-21 14:10   ` Ingo Molnar
2014-01-21 14:11   ` Jan Kiszka
2014-01-21 14:34     ` Jan Kiszka
2014-01-21 14:51   ` Peter Zijlstra
2014-01-21 23:20     ` Huang Ying
2014-01-22 18:43       ` Andi Kleen
2014-01-23 18:51         ` Jan Kiszka
2014-01-23 19:11           ` Peter Zijlstra [this message]
2014-01-23 19:22           ` Andi Kleen
2014-01-23 19:51             ` Jan Kiszka
2014-01-23 20:17               ` Andi Kleen

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