Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S275361AbTHGOjH (ORCPT ); Thu, 7 Aug 2003 10:39:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S275354AbTHGOiX (ORCPT ); Thu, 7 Aug 2003 10:38:23 -0400 Received: from fw.osdl.org ([65.172.181.6]:8371 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S275353AbTHGOiP (ORCPT ); Thu, 7 Aug 2003 10:38:15 -0400 Subject: [PATCH] linux-2.6.0-test2_mtrr-race-fix_A0 From: Mark Haverkamp To: Andrew Morton Cc: lkml , john stultz In-Reply-To: <1060192965.10732.58.camel@cog.beaverton.ibm.com> References: <200308061052.18550.Mathias.Froehlich@web.de> <1060190104.10732.52.camel@cog.beaverton.ibm.com> <1060193108.12048.4.camel@markh1.pdx.osdl.net> <1060192965.10732.58.camel@cog.beaverton.ibm.com> Content-Type: text/plain Message-Id: <1060267092.24115.8.camel@markh1.pdx.osdl.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.4 Date: Thu, 07 Aug 2003 07:38:12 -0700 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1741 Lines: 65 On Wed, 2003-08-06 at 11:02, john stultz wrote: > On Wed, 2003-08-06 at 11:05, Mark Haverkamp wrote: > > On Wed, 2003-08-06 at 10:15, john stultz wrote: > > > > > > Well, let me look at it again and see if I can come up with a proper > > > fix. > > I added an extra sync up from the caller after the last gate change so > > it is the last one to touch the automatic data. > > Ah, you beat me to it! > > I'm actually testing the very same change (comments differ a touch, but > that's ok). > > Looks good. If everyone is happy I'd say resubmit it to Andrew. > > thanks > -john I'd like to submit this patch for inclusion. It adds an extra sync up in set_mtrr and ipi_handler to make sure that set_mtrr is the last to touch the automatic set_mtrr_data. ===== arch/i386/kernel/cpu/mtrr/main.c 1.29 vs edited ===== --- 1.29/arch/i386/kernel/cpu/mtrr/main.c Tue Jul 15 10:08:48 2003 +++ edited/arch/i386/kernel/cpu/mtrr/main.c Wed Aug 6 10:46:00 2003 @@ -169,6 +169,7 @@ cpu_relax(); barrier(); } + atomic_dec(&data->count); local_irq_restore(flags); } @@ -256,8 +257,18 @@ cpu_relax(); barrier(); } - local_irq_restore(flags); + atomic_set(&data.count, num_booting_cpus() - 1); atomic_set(&data.gate,0); + + /* + * Wait here for everyone to have seen the gate change + * So we're the last ones to touch 'data' + */ + while(atomic_read(&data.count)) { + cpu_relax(); + barrier(); + } + local_irq_restore(flags); } /** -- Mark Haverkamp - 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/