From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 22 Oct 2002 13:36:49 -0500 From: Dave McCracken Subject: Re: [PATCH 2.5.43-mm2] New shared page table patch Message-ID: <145460000.1035311809@baldur.austin.ibm.com> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel , Andrew Morton Cc: "Eric W. Biederman" , "Martin J. Bligh" , Bill Davidsen , Linux Kernel , Linux Memory Management List-ID: --On Tuesday, October 22, 2002 15:15:29 -0200 Rik van Riel wrote: >> Or large pages. I confess to being a little perplexed as to >> why we're pursuing both. > > I guess that's due to two things. > > 1) shared pagetables can speed up fork()+exec() somewhat > > 2) if we have two options that fix the Oracle problem, > there's a better chance of getting at least one of > the two merged ;) And 3) The current large page implementation is only for applications that want anonymous *non-pageable* shared memory. Shared page tables reduce resource usage for any shared area that's mapped at a common address and is large enough to span entire pte pages. Since all pte pages are shared on a COW basis at fork time, children will continue to share all large read-only areas with their parent, eg large executables. Dave McCracken ====================================================================== Dave McCracken IBM Linux Base Kernel Team 1-512-838-3059 dmccr@us.ibm.com T/L 678-3059 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/