From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 25 Jul 2007 01:31:44 -0700 (PDT) From: david@lang.hm Subject: Re: -mm merge plans for 2.6.23 In-Reply-To: <46A709DC.4080501@gmail.com> Message-ID: References: <20070710013152.ef2cd200.akpm@linux-foundation.org> <200707102015.44004.kernel@kolivas.org> <9a8748490707231608h453eefffx68b9c391897aba70@mail.gmail.com> <46A57068.3070701@yahoo.com.au> <2c0942db0707232153j3670ef31kae3907dff1a24cb7@mail.gmail.com> <46A58B49.3050508@yahoo.com.au> <2c0942db0707240915h56e007e3l9110e24a065f2e73@mail.gmail.com> <46A7031D.5080300@gmail.com> <46A709DC.4080501@gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: owner-linux-mm@kvack.org Return-Path: To: Rene Herman Cc: Ray Lee , Nick Piggin , Jesper Juhl , Andrew Morton , ck list , Ingo Molnar , Paul Jackson , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Wed, 25 Jul 2007, Rene Herman wrote: > On 07/25/2007 10:07 AM, david@lang.hm wrote: > >> On Wed, 25 Jul 2007, Rene Herman wrote: > >> > Something like this? > > [ ... ] > >> when the swap readahead is enabled does it make a significant difference >> in the time to do the random access? > > I don't use swap prefetch (nor -ck or -mm). If someone who has the patch > applied waits to hit enter until swap prefetch has prefetched it all back in > again, it certainly will. > > Swap prefetch's potential to do larger reads back from swapspace than a > random segfaulting app could well be very significant. Reads are dwarved by > seeks. If this program does what you wanted, please use it to show us. I haven't used swap prefetch either, the call was put out for what could be used to test the performance, and I was suggesting a test. if nobody else follows up on this I'll try to get some time to test it myself in a day or two. David Lang -- 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