From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1767543AbXCIVTv (ORCPT ); Fri, 9 Mar 2007 16:19:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1767542AbXCIVTv (ORCPT ); Fri, 9 Mar 2007 16:19:51 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:2218 "EHLO spitz.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2993147AbXCIVTt (ORCPT ); Fri, 9 Mar 2007 16:19:49 -0500 Date: Fri, 9 Mar 2007 21:07:46 +0000 From: Pavel Machek To: "Rafael J. Wysocki" Cc: Andrew Morton , LKML Subject: Re: [PATCH] swsusp: Disable nonboot CPUs before entering platform suspend Message-ID: <20070309210746.GA6374@ucw.cz> References: <200703072044.12021.rjw@sisk.pl> <200703090858.55632.rjw@sisk.pl> <20070309085420.GA26786@atrey.karlin.mff.cuni.cz> <200703092107.23820.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200703092107.23820.rjw@sisk.pl> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > > > > Index: linux-2.6.21-rc2-mm2/kernel/power/disk.c > > > > > =================================================================== > > > > > --- linux-2.6.21-rc2-mm2.orig/kernel/power/disk.c > > > > > +++ linux-2.6.21-rc2-mm2/kernel/power/disk.c > > > > > @@ -61,6 +61,7 @@ static void power_down(suspend_disk_meth > > > > > switch(mode) { > > > > > case PM_DISK_PLATFORM: > > > > > if (pm_ops && pm_ops->enter) { > > > > > + disable_nonboot_cpus(); > > > > > kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK); > > > > > pm_ops->enter(PM_SUSPEND_DISK); > > > > > break; > > > > > > > > ...so, if pm_ops is non-null, power_down does nonboot cpu disabling, > > > > otherwise we proceed with cpus enabled? > > > > > > > > That looks ugly. > > > > > > > > Is the warning bogus? > > > > > > Well, maybe. I'm not sure. > > > > > > > Or maybe we should *always* disable nonboot cpus in powerdown path? > > > > > > I think we should do that. > > > > That would be acceptable. > > > > > > > Index: linux-2.6.21-rc2-mm2/kernel/power/user.c > > > > > =================================================================== > > > > > --- linux-2.6.21-rc2-mm2.orig/kernel/power/user.c > > > > > +++ linux-2.6.21-rc2-mm2/kernel/power/user.c > > > > > @@ -398,9 +398,9 @@ static int snapshot_ioctl(struct inode * > > > > > > > > > > case PMOPS_ENTER: > > > > > if (data->platform_suspend) { > > > > > + disable_nonboot_cpus(); > > > > > kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK); > > > > > error = pm_ops->enter(PM_SUSPEND_DISK); > > > > > - error = 0; > > > > > } > > > > > break; > > > > > > > > Foe an userland application, disabling cpus during pmops_enter is at > > > > least surprising....... > > > > > > Yes, but this is not a usual ioctl(). OTOH, we can call enable_nonboot_cpus() > > > if pm_ops->enter(PM_SUSPEND_DISK) returns an error (otherwise it souldn't > > > return at all, no?). > > > > Ok. > > Well, does the appended patch look better? Yes. > --- > kernel/power/disk.c | 1 + > kernel/power/user.c | 3 ++- > 2 files changed, 3 insertions(+), 1 deletion(-) > > Index: linux-2.6.21-rc3/kernel/power/disk.c > =================================================================== > --- linux-2.6.21-rc3.orig/kernel/power/disk.c > +++ linux-2.6.21-rc3/kernel/power/disk.c > @@ -58,6 +58,7 @@ static inline int platform_prepare(void) > > static void power_down(suspend_disk_method_t mode) > { > + disable_nonboot_cpus(); > switch(mode) { > case PM_DISK_PLATFORM: > if (pm_ops && pm_ops->enter) { > Index: linux-2.6.21-rc3/kernel/power/user.c > =================================================================== > --- linux-2.6.21-rc3.orig/kernel/power/user.c > +++ linux-2.6.21-rc3/kernel/power/user.c > @@ -402,9 +402,10 @@ static int snapshot_ioctl(struct inode * > > case PMOPS_ENTER: > if (data->platform_suspend) { > + disable_nonboot_cpus(); > kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK); > error = pm_ops->enter(PM_SUSPEND_DISK); > - error = 0; > + enable_nonboot_cpus(); Why did we discard return code in previous versions? Do we still want to do that? -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html