From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by wr-out-0506.google.com with SMTP id c30so64919wra.14 for ; Thu, 18 Sep 2008 16:16:43 -0700 (PDT) Message-ID: <28c262360809181616p481f9126p50c9a8c971fbbf9e@mail.gmail.com> Date: Fri, 19 Sep 2008 08:16:43 +0900 From: "MinChan Kim" Subject: Re: Populating multiple ptes at fault time In-Reply-To: <48D2D4C7.8080209@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <48D142B2.3040607@goop.org> <33307c790809181411j41a6fc4ev8560a13ed8661ec2@mail.gmail.com> <48D2C46A.5030702@linux-foundation.org> <33307c790809181421k52ed6a36h9d4ee40d5799a536@mail.gmail.com> <48D2C8DD.4040303@linux-foundation.org> <28c262360809181449v1050c1f7ndf17dadba9fac0bf@mail.gmail.com> <48D2CEF3.6060308@linux-foundation.org> <33307c790809181508v2e64c0a4j8f0e93df99673e63@mail.gmail.com> <48D2D22B.2070408@linux-foundation.org> <48D2D4C7.8080209@redhat.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Chris Snook Cc: Christoph Lameter , Martin Bligh , Jeremy Fitzhardinge , Nick Piggin , Hugh Dickens , Linux Memory Management List , Linux Kernel Mailing List , Avi Kivity , Andrew Morton , Rik van Riel List-ID: On Fri, Sep 19, 2008 at 7:23 AM, Chris Snook wrote: > Christoph Lameter wrote: >> >> Martin Bligh wrote: >>>> >>>> My patches were only for anonymous pages not for file backed because >>>> readahead >>>> is available for file backed mappings. >>> >>> Do we populate the PTEs though? I didn't think that was batched, but I >>> might well be wrong. >> >> We do not populate the PTEs and AFAICT PTE population was assumed not to >> be >> performance critical since the backing media is comparatively slow. >> > > Perhaps we should. In a virtual guest, the backing media is often an > emulated IDE device, or something similarly inefficient, such that the > bottleneck is the CPU. In embedded environment, many people use nand-like device as storage. Read cost of nand-like device is less than IDE's one. Also, Nowaday Embedded stuff would like to use multi-core step by step. So, pte population become important more and more. > -- Chris > -- Kinds regards, MinChan Kim -- 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/ . Don't email: email@kvack.org