Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753505Ab1CPPzR (ORCPT ); Wed, 16 Mar 2011 11:55:17 -0400 Received: from kroah.org ([198.145.64.141]:50178 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753494Ab1CPPzN (ORCPT ); Wed, 16 Mar 2011 11:55:13 -0400 Date: Wed, 16 Mar 2011 08:51:04 -0700 From: Greg KH To: Shaohua Li Cc: lkml , linux-mm , Rik van Riel , "Mallick, Asit K" , stable , y-goto@jp.fujitsu.com, Ingo Molnar , Andrew Morton Subject: Re: [stable] [PATCH]x86: flush tlb if PGD entry is changed in i386 PAE mode Message-ID: <20110316155104.GA25008@kroah.com> References: <1300246649.2337.95.camel@sli10-conroe> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1300246649.2337.95.camel@sli10-conroe> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1249 Lines: 27 On Wed, Mar 16, 2011 at 11:37:29AM +0800, Shaohua Li wrote: > According to intel CPU manual, every time PGD entry is changed in i386 PAE mode, > we need do a full TLB flush. Current code follows this and there is comment > for this too in the code. But current code misses the multi-threaded case. A > changed page table might be used by several CPUs, every such CPU should flush > TLB. > Usually this isn't a problem, because we prepopulate all PGD entries at process > fork. But when the process does munmap and follows new mmap, this issue will be > triggered. When it happens, some CPUs will keep doing page fault. > > See: http://marc.info/?l=linux-kernel&m=129915020508238&w=2 > > Reported-by: Yasunori Goto > Signed-off-by: Shaohua Li > Tested-by: Yasunori Goto This is not how you submit something to the stable kernel tree. Please go read Documentation/stable_kernel_rules.txt for how to do it properly. thanks, greg k-h -- 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/