Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754370AbbFJW6K (ORCPT ); Wed, 10 Jun 2015 18:58:10 -0400 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:51507 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752423AbbFJW54 (ORCPT ); Wed, 10 Jun 2015 18:57:56 -0400 Date: Wed, 10 Jun 2015 23:57:44 +0100 From: Russell King - ARM Linux To: Stephen Boyd Cc: Mark Rutland , Nicolas Pitre , Tyler Baker , linux-sh@vger.kernel.org, Magnus Damm , linux-kernel@vger.kernel.org, Simon Horman , Geert Uytterhoeven , Dave Martin , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v5] ARM: smp: Only expose /sys/.../cpuX/online if hotpluggable Message-ID: <20150610225744.GT7557@n2100.arm.linux.org.uk> References: <1428705191-15670-1-git-send-email-sboyd@codeaurora.org> <20150413134246.GS12732@n2100.arm.linux.org.uk> <557739AC.8000903@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <557739AC.8000903@codeaurora.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3373 Lines: 75 On Tue, Jun 09, 2015 at 12:08:28PM -0700, Stephen Boyd wrote: > On 04/13/2015 06:42 AM, Russell King - ARM Linux wrote: > > On Fri, Apr 10, 2015 at 03:33:11PM -0700, Stephen Boyd wrote: > >> Writes to /sys/.../cpuX/online fail if we determine the platform > >> doesn't support hotplug for that CPU. Furthermore, if the cpu_die > >> op isn't specified the system hangs when we try to offline a CPU > >> and it comes right back online unexpectedly. Let's figure this > >> stuff out before we make the sysfs nodes so that the online file > >> doesn't even exist if it isn't (at least sometimes) possible to > >> hotplug the CPU. > >> > >> Add a new 'cpu_can_disable' op and repoint all 'cpu_disable' > >> implementations at it because all implementers use the op to > >> indicate if a CPU can be hotplugged or not in a static fashion. > >> With PSCI we may need to add a 'cpu_disable' op so that the > >> secure OS can be migrated off the CPU we're trying to hotplug. > >> In this case, the 'cpu_can_disable' op will indicate that all > >> CPUs are hotpluggable by returning true, but the 'cpu_disable' op > >> will make a PSCI migration call and occasionally fail, denying > >> the hotplug of a CPU. This shouldn't be any worse than x86 where > >> we may indicate that all CPUs are hotpluggable but occasionally > >> we can't offline a CPU due to check_irq_vectors_for_cpu_disable() > >> failing to find a CPU to move vectors to. > >> > >> Cc: Mark Rutland > >> Cc: Nicolas Pitre > >> Cc: Dave Martin > >> Acked-by: Simon Horman [shmobile portion] > >> Tested-by: Simon Horman > >> Cc: Magnus Damm > >> Cc: > >> Cc: Tyler Baker > >> Cc: Geert Uytterhoeven > >> Signed-off-by: Stephen Boyd > > Let's see some more acks for this... > > > > Nobody else has acked this so far. Shall I put it in the patch tracker > now? Or is there someone more specific we need an ack from? The version you've put in the patch tracker is not the version you posted. It contains this change: diff --git a/arch/arm/mach-shmobile/common.h b/arch/arm/mach-shmobile/common.h index 476092b86c6e..f2c4bf437ea7 100644 --- a/arch/arm/mach-shmobile/common.h +++ b/arch/arm/mach-shmobile/common.h @@ -13,7 +13,8 @@ extern void shmobile_smp_boot(void); extern void shmobile_smp_sleep(void); extern void shmobile_smp_hook(unsigned int cpu, unsigned long fn, unsigned long arg); -extern int shmobile_smp_cpu_disable(unsigned int cpu); +extern bool shmobile_smp_cpu_can_disable(unsigned int cpu); +extern void shmobile_invalidate_start(void); which your original patch did not include. The tree I'm applying to (-rc1) contains: extern int shmobile_smp_cpu_disable(unsigned int cpu); extern void shmobile_invalidate_start(void); there. Hence git quite rightfully declines to apply the patch. Please fix. Thanks. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- 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/