From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 933A06B004D for ; Fri, 13 Nov 2009 15:14:57 -0500 (EST) From: "Rafael J. Wysocki" Subject: Re: [PATCH] Allow memory hotplug and hibernation in the same kernel Date: Fri, 13 Nov 2009 21:16:02 +0100 References: <20091113105944.GA16028@basil.fritz.box> In-Reply-To: <20091113105944.GA16028@basil.fritz.box> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200911132116.02659.rjw@sisk.pl> Sender: owner-linux-mm@kvack.org To: Andi Kleen Cc: akpm@linux-foundation.org, linux-mm@kvack.org, gerald.schaefer@de.ibm.com, linux-kernel@vger.kernel.org List-ID: On Friday 13 November 2009, Andi Kleen wrote: > Allow memory hotplug and hibernation in the same kernel > > Memory hotplug and hibernation was excluded in Kconfig. This is obviously > a problem for distribution kernels who want to support both in the same > image. > > After some discussions with Rafael and others the only problem is > with parallel memory hotadd or removal while a hibernation operation > is in process. It was also working for s390 before. > > This patch removes the Kconfig level exclusion, and simply > makes the memory add / remove functions grab the pm_mutex > to exclude against hibernation. > > This is a 2.6.32 candidate. > > Cc: gerald.schaefer@de.ibm.com > Cc: rjw@sisk.pl > > Signed-off-by: Andi Kleen > > --- > include/linux/suspend.h | 21 +++++++++++++++++++-- > mm/Kconfig | 5 +---- > mm/memory_hotplug.c | 21 +++++++++++++++++---- > 3 files changed, 37 insertions(+), 10 deletions(-) > > Index: linux-2.6.32-rc6-ak/include/linux/suspend.h > =================================================================== > --- linux-2.6.32-rc6-ak.orig/include/linux/suspend.h > +++ linux-2.6.32-rc6-ak/include/linux/suspend.h > @@ -301,6 +301,8 @@ static inline int unregister_pm_notifier > #define pm_notifier(fn, pri) do { (void)(fn); } while (0) > #endif /* !CONFIG_PM_SLEEP */ > > +extern struct mutex pm_mutex; > + > #ifndef CONFIG_HIBERNATION > static inline void register_nosave_region(unsigned long b, unsigned long e) > { > @@ -308,8 +310,23 @@ static inline void register_nosave_regio > static inline void register_nosave_region_late(unsigned long b, unsigned long e) > { > } > -#endif > > -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); > +} This also is going to affect suspend to RAM, which kind of makes sense BTW, so I'd not put it under the #ifdef. Also, the names should reflect the fact that suspend is affected too. What about block|unblock_system_sleep()? > +#endif > > #endif /* _LINUX_SUSPEND_H */ The rest of the patch is fine by me. Thanks, Rafael -- 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