From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id C79B06B006A for ; Fri, 13 Nov 2009 19:08:58 -0500 (EST) Date: Sat, 14 Nov 2009 01:08:49 +0100 From: Andi Kleen Subject: Re: [PATCH] Allow memory hotplug and hibernation in the same kernel Message-ID: <20091114000849.GG30880@basil.fritz.box> References: <20091113105944.GA16028@basil.fritz.box> <20091113155102.3480907f.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091113155102.3480907f.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: Andi Kleen , linux-mm@kvack.org, gerald.schaefer@de.ibm.com, rjw@sisk.pl, linux-kernel@vger.kernel.org List-ID: On Fri, Nov 13, 2009 at 03:51:02PM -0800, Andrew Morton wrote: > > ... > > > > +extern struct mutex pm_mutex; > > Am a bit worried by the new mutex. It's not a new mutex, just the existing one already used by suspend. I only extended it's coverage to two more code paths. > > > -extern struct mutex pm_mutex; > > +static inline void lock_hibernation(void) {} > > +static inline void unlock_hibernation(void) {} > > + > > +#else > > + > > +/* Let some subsystems like memory hotadd exclude hibernation */ > > + > > +static inline void lock_hibernation(void) > > +{ > > + mutex_lock(&pm_mutex); > > +} > > + > > +static inline void unlock_hibernation(void) > > +{ > > + mutex_unlock(&pm_mutex); > > +} > > +#endif > > Has this been carefully reviewed and lockdep-tested to ensure that we > didn't introduce any ab/ba nasties? It's a "outer" global mutex for both, so I don't expect ABBA issues. I tested hotadd/hotremove with lockdep and nothing showed up. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org