From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754198AbYIHOPx (ORCPT ); Mon, 8 Sep 2008 10:15:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751255AbYIHOPp (ORCPT ); Mon, 8 Sep 2008 10:15:45 -0400 Received: from qw-out-2122.google.com ([74.125.92.25]:35436 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751243AbYIHOPo (ORCPT ); Mon, 8 Sep 2008 10:15:44 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=CiP8IcoYZyJO2O7tYK91/X+OK5G85JQKX9ueKhR90muzQGb1csS/yIxjGIXv4XV8ZD dDN9bifIfdNmthjcZh6N3F23Nii11u+uYXumsSSBsEmNokZEXfmhqckaDyLQlr/MEW9A eHU/UFXaplSkXs2wsoOe9RUjWo2N4s8BB/c1E= Message-ID: <921ca19c0809080715m6379b322x79edb239f6971560@mail.gmail.com> Date: Mon, 8 Sep 2008 19:45:43 +0530 From: "Sujit Karataparambil" Subject: Re: [PATCH] Convert tlbstate_lock spin_lock to raw_spin_lock Cc: linux-rt-users@vger.kernel.org In-Reply-To: <20080908073732.GC5798@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <2c6d8d720809071806i54e58093vf87bec5175d9b074@mail.gmail.com> <20080908073732.GC5798@linux.vnet.ibm.com> To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Chirag, Kindly understand what xavier is trying to do. He is Trying to disable smp. The RT - Linux Code is dependent on the mutex lock to perform some soft/hard real time processing. This is an problem with the mutex lock. Kindly check with some one before signing off patches. Thanks, Sujit On 9/8/08, Chirag Jog wrote: > * 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, > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- --linux(2.4/2.6),bsd(4.5.x+),solaris(2.5+)