Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760715AbZLJIAM (ORCPT ); Thu, 10 Dec 2009 03:00:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760673AbZLJIAH (ORCPT ); Thu, 10 Dec 2009 03:00:07 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:46271 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760650AbZLJIAF (ORCPT ); Thu, 10 Dec 2009 03:00:05 -0500 Date: Thu, 10 Dec 2009 08:59:47 +0100 From: Ingo Molnar To: "Rafael J. Wysocki" Cc: Alan Stern , Linus Torvalds , Zhang Rui , LKML , ACPI Devel Maling List , pm list , Peter Zijlstra , David Chinner , Lachlan McIlroy Subject: Re: spinlock in completion_done() (was: Re: Async resume patch (was: Re: [GIT PULL] PM updates for 2.6.33)) Message-ID: <20091210075947.GD25549@elte.hu> References: <200912082248.14138.rjw@sisk.pl> <20091209092922.GC28428@elte.hu> <200912092337.52492.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200912092337.52492.rjw@sisk.pl> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1708 Lines: 47 * Rafael J. Wysocki wrote: > On Wednesday 09 December 2009, Ingo Molnar wrote: > > > > * Rafael J. Wysocki wrote: > > > > > On Tuesday 08 December 2009, Alan Stern wrote: > > > > On Tue, 8 Dec 2009, Rafael J. Wysocki wrote: > > > > > > > > > BTW, is there a good reason why completion_done() doesn't use spin_lock_irqsave > > > > > and spin_unlock_irqrestore? complete() and complete_all() use them, so why not > > > > > here? > > > > > > > > And likewise in try_wait_for_completion(). It looks like a bug. Maybe > > > > these routines were not intended to be called with interrupts disabled, > > > > but that requirement doesn't seem to be documented. And it isn't a > > > > natural requirement anyway. > > > > > > OK, let's ask Ingo about that. > > > > > > Ingo, is there any particular reason why completion_done() and > > > try_wait_for_completion() don't use spin_lock_irqsave() and > > > spin_unlock_irqrestore()? > > > > that's a bug that should be fixed - all the wakeup side (and atomic) > > variants of completetion API should be irq safe. > > > > It appears that these new completion APIs were added via the XFS tree > > about a year ago: > > > > 39d2f1a: [XFS] extend completions to provide XFS object flush requirements > > > > Please Cc: scheduler folks to all scheduler patches. > > If you haven't fixed it locally yet, would you mind me posting a fix? I wouldnt mind it at all. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/