From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758563AbXFPOyx (ORCPT ); Sat, 16 Jun 2007 10:54:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756792AbXFPOyr (ORCPT ); Sat, 16 Jun 2007 10:54:47 -0400 Received: from www.osadl.org ([213.239.205.134]:52095 "EHLO mail.tglx.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756205AbXFPOyq (ORCPT ); Sat, 16 Jun 2007 10:54:46 -0400 Subject: Re: [patch-mm 01/25] NOHZ: Fix nox x86 dyntick idle handling From: Thomas Gleixner To: Bernhard Rosenkraenzer Cc: LKML , Andrew Morton , Ingo Molnar , Andi Kleen , Chris Wright , Arjan van de Ven , Venkatesh Pallipadi , Adam Belay , Len Brown , Dave Miller , Paul Mundt , Russell King In-Reply-To: <200706161636.50661.bero@arklinux.org> References: <20070616101126.296384219@inhelltoy.tec.linutronix.de> <20070616101636.556333444@inhelltoy.tec.linutronix.de> <200706161636.50661.bero@arklinux.org> Content-Type: text/plain Date: Sat, 16 Jun 2007 16:54:43 +0200 Message-Id: <1182005683.8176.369.camel@chaos> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 (2.10.1-4.fc7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2007-06-16 at 16:36 +0200, Bernhard Rosenkraenzer wrote: > On Saturday 16 June 2007, Thomas Gleixner wrote: > > > +#if defined(CONFIG_NO_HZ) && !defined(CONFIG_NONIRQ_WAKEUP) > > + /* Make sure that timer wheel updates are propagated */ > > + if (!in_interrupt() && idle_cpu(smp_processor_id()) && !need_resched()) > > + tick_nohz_stop_sched_tick();a > > +#endif > > preempt_enable_no_resched(); > > } > > The bit above breaks the build for a CONFIG_NO_HZ build without > CONFIG_NONIRQ_WAKEUP -- please remove the extra "a" after > tick_nohz_stop_sched_tick(); before applying this. Oops. Must have happened when I edited the mailbox. Replacement patch below: tglx ---------------------> Subject: NOHZ: Fix nox x86 dyntick idle handling The cpuidle patches moved the tick nohz handling from irq_exit into the inner idle loop. The change is correct as it covers non interrupt based wakeups (e.g DMA) on x86 as well, but the move breaks ARM, SH and SPARC64. Keep the original implementation and deselet the irq exit code for those architectures which have no irq idle wakeups. This way the non affected architectures are not burdened with the extra changes in the idle implementation. Signed-off-by: Thomas Gleixner Cc: Adam Belay Cc: Len Brown Cc: Dave Miller Cc: Paul Mundt Cc: Russell King --- arch/i386/Kconfig | 4 ++++ kernel/softirq.c | 5 +++++ 2 files changed, 9 insertions(+) Index: linux-2.6.22-rc4-mm/arch/i386/Kconfig =================================================================== --- linux-2.6.22-rc4-mm.orig/arch/i386/Kconfig 2007-06-16 17:04:14.000000000 +0200 +++ linux-2.6.22-rc4-mm/arch/i386/Kconfig 2007-06-16 17:04:18.000000000 +0200 @@ -31,6 +31,10 @@ config GENERIC_CLOCKEVENTS_BROADCAST default y depends on X86_LOCAL_APIC +config NONIRQ_WAKEUP + bool + default y + config LOCKDEP_SUPPORT bool default y Index: linux-2.6.22-rc4-mm/kernel/softirq.c =================================================================== --- linux-2.6.22-rc4-mm.orig/kernel/softirq.c 2007-06-16 17:04:14.000000000 +0200 +++ linux-2.6.22-rc4-mm/kernel/softirq.c 2007-06-16 17:04:39.000000000 +0200 @@ -304,6 +304,11 @@ void irq_exit(void) if (!in_interrupt() && local_softirq_pending()) invoke_softirq(); +#if defined(CONFIG_NO_HZ) && !defined(CONFIG_NONIRQ_WAKEUP) + /* Make sure that timer wheel updates are propagated */ + if (!in_interrupt() && idle_cpu(smp_processor_id()) && !need_resched()) + tick_nohz_stop_sched_tick(); +#endif preempt_enable_no_resched(); }