From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2993040AbXCIHhP (ORCPT ); Fri, 9 Mar 2007 02:37:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2993061AbXCIHhP (ORCPT ); Fri, 9 Mar 2007 02:37:15 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:2524 "EHLO spitz.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2993040AbXCIHhM (ORCPT ); Fri, 9 Mar 2007 02:37:12 -0500 Date: Wed, 7 Mar 2007 21:07:17 +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: <20070307210716.GA4913@ucw.cz> References: <200703072044.12021.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200703072044.12021.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! > Prevent the WARN_ON() in arch/x86_64/kernel/acpi/sleep.c:init_low_mapping() > from triggering by disabling nonboot CPUs before we finally enter the platform > suspend. > > Signed-off-by: Rafael J. Wysocki > --- > kernel/power/disk.c | 1 + > kernel/power/user.c | 2 +- > 2 files changed, 2 insertions(+), 1 deletion(-) > > 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? Or maybe we should *always* disable nonboot cpus in powerdown path? > 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....... -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html