Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966593AbWKOIBf (ORCPT ); Wed, 15 Nov 2006 03:01:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S966636AbWKOIBf (ORCPT ); Wed, 15 Nov 2006 03:01:35 -0500 Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:8927 "EHLO sous-sol.org") by vger.kernel.org with ESMTP id S966593AbWKOIBd (ORCPT ); Wed, 15 Nov 2006 03:01:33 -0500 Date: Wed, 15 Nov 2006 00:03:23 -0800 From: Chris Wright To: Andi Kleen Cc: Zachary Amsden , Andi Kleen , virtualization@lists.osdl.org, Andrew Morton , Chris Wright , Linux Kernel Mailing List Subject: Re: [PATCH 1/5] Skip timer works.patch Message-ID: <20061115080323.GK1397@sequoia.sous-sol.org> References: <200610200009.k9K09MrS027558@zach-dev.vmware.com> <20061027145650.GA37582@muc.de> <45425976.3090508@vmware.com> <200610271416.12548.ak@suse.de> <4546669F.8020706@vmware.com> <20061030225016.GA95732@muc.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061030225016.GA95732@muc.de> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3846 Lines: 110 * Andi Kleen (ak@muc.de) wrote: > On Mon, Oct 30, 2006 at 12:54:55PM -0800, Zachary Amsden wrote: > > Andi Kleen wrote: > > >no_timer_check. But it's only there on x86-64 in mainline - although there > > >were some patches to add it to i386 too. > > > > > > > I can rename to match the x86-64 name. > > I will do that in my tree. Looks like this one might have been lost. Here's the renamed version (it's against 2.6.19-rc5-mm2, which should have your tree in it). thanks, -chris -- From: Zachary Amsden Add a way to disable the timer IRQ routing check via a boot option. The VMI timer code uses this to avoid triggering the pester Mingo code, which probes for some very unusual and broken motherboard routings. It fires 100% of the time when using a paravirtual delay mechanism instead of using a realtime delay, since there is no elapsed real time, and the 4 timer IRQs have not yet been delivered. In addition, it is entirely possible, though improbable, that this bug could surface on real hardware which picks a particularly bad time to enter SMM mode, causing a long latency during one of the timer IRQs. While here, make check_timer be __init. Signed-off-by: Zachary Amsden [chrisw: use no_timer_check to bring inline with x86_64 as per Andi's request] Signed-off-by: Chris Wright =================================================================== --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -610,8 +610,6 @@ and is between 256 and 4096 characters. hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages. - noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing - i8042.direct [HW] Put keyboard port into non-translated mode i8042.dumbkbd [HW] Pretend that controller can only read data from keyboard and cannot control its state @@ -1081,8 +1079,13 @@ and is between 256 and 4096 characters. in certain environments such as networked servers or real-time systems. + noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing + noirqdebug [IA-32] Disables the code which attempts to detect and disable unhandled interrupt sources. + + no_timer_check [IA-32,X86_64,APIC] Disables the code which tests for + broken timer IRQ sources. noisapnp [ISAPNP] Disables ISA PnP code. =================================================================== --- a/arch/i386/kernel/io_apic.c +++ b/arch/i386/kernel/io_apic.c @@ -1931,6 +1931,15 @@ static void __init setup_ioapic_ids_from static void __init setup_ioapic_ids_from_mpc(void) { } #endif +static int no_timer_check __initdata; + +static int __init notimercheck(char *s) +{ + no_timer_check = 1; + return 1; +} +__setup("no_timer_check", notimercheck); + /* * There is a nasty bug in some older SMP boards, their mptable lies * about the timer IRQ. We do the following to work around the situation: @@ -1939,9 +1948,12 @@ static void __init setup_ioapic_ids_from * - if this function detects that timer IRQs are defunct, then we fall * back to ISA timer IRQs */ -static int __init timer_irq_works(void) +int __init timer_irq_works(void) { unsigned long t1 = jiffies; + + if (no_timer_check) + return 1; local_irq_enable(); /* Let ten ticks pass... */ @@ -2219,7 +2231,7 @@ int timer_uses_ioapic_pin_0; * is so screwy. Thanks to Brian Perkins for testing/hacking this beast * fanatically on his truly buggy board. */ -static inline void check_timer(void) +static inline void __init check_timer(void) { int apic1, pin1, apic2, pin2; int vector; - 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/