From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753146AbYIHHlU (ORCPT ); Mon, 8 Sep 2008 03:41:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751482AbYIHHlK (ORCPT ); Mon, 8 Sep 2008 03:41:10 -0400 Received: from e28smtp04.in.ibm.com ([59.145.155.4]:52876 "EHLO e28esmtp04.in.ibm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751237AbYIHHlI (ORCPT ); Mon, 8 Sep 2008 03:41:08 -0400 Date: Mon, 8 Sep 2008 13:07:32 +0530 From: Chirag Jog To: xavier droubay Cc: linux-rt-users@vger.kernel.org, LKML , Steven Rostedt , Thomas Gleixner Subject: [PATCH] Convert tlbstate_lock spin_lock to raw_spin_lock Message-ID: <20080908073732.GC5798@linux.vnet.ibm.com> Reply-To: Chirag Jog Mail-Followup-To: xavier droubay , linux-rt-users@vger.kernel.org, LKML , Steven Rostedt , Thomas Gleixner References: <2c6d8d720809071806i54e58093vf87bec5175d9b074@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <2c6d8d720809071806i54e58093vf87bec5175d9b074@mail.gmail.com> Organization: IBM LTC User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * xavier droubay [2008-09-08 03:06:51]: > Hello, > > I experienced this "rtmutex.c:743" known bug with rt3 patch, using > > http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.26.3.tar.bz2 > http://rt.et.redhat.com/download/patch-2.6.26.3-rt3.bz2 > > I compiled this kernel with the "make-kpkg" debian utility. > > I first compiled this kernel with NO SMP, NO HIGHMEM, and partial ACPI > (without fan, processor, ... modules). Attached file > "config-2.6.26.3-rt3lowlty.frwr.gz". > I didn't experience any problem with this kernel. > > I then enabled SMP and HIGHMEM, and experienced "rtmutex.c:743" BUG. > Attached files > "config-2.6.26.3-rt3rt-smp-hm.gz" and "dmesg.gz" for some BUGGY message. > > > I have seen somewhere on the archive, that some people still > experienced problems with SMP. > I guess no fix has been done from rt3 to rt7 patch. Can you confirm? > > If so, which recent kernel should I use in order to get smp and rt > running without problems? > This simple patch should solve the above problem. Seeing the config, its seems to be a 32bit box. It convert tlbstate_lock spin_lock to raw_spin_lock. Preemption has already been disabled, hence this change shouldn't affect latency numbers. Signed-Off-By: Chirag diff --git a/arch/x86/kernel/tlb_32.c b/arch/x86/kernel/tlb_32.c index 9bb2363..228849c 100644 --- a/arch/x86/kernel/tlb_32.c +++ b/arch/x86/kernel/tlb_32.c @@ -23,7 +23,7 @@ DEFINE_PER_CPU(struct tlb_state, cpu_tlbstate) static cpumask_t flush_cpumask; static struct mm_struct *flush_mm; static unsigned long flush_va; -static DEFINE_SPINLOCK(tlbstate_lock); +static DEFINE_RAW_SPINLOCK(tlbstate_lock); /* * We cannot call mmdrop() because we are in interrupt context,