From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fgwnews.fujitsu.co.jp (fgwnews.fujitsu.co.jp [164.71.1.134]) by kvack.org (8.8.7/8.8.7) with ESMTP id VAA07973 for ; Tue, 8 Dec 1998 21:45:02 -0500 Message-Id: <199812090241.LAA15658@fireball.otsd.ts.fujitsu.co.jp> Subject: Re: [PATCH] swapin readahead and fixes From: Drago Goricanec In-Reply-To: Your message of "Tue, 8 Dec 1998 03:31:25 +0100 (CET)" References: Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Wed, 09 Dec 1998 11:41:52 +0900 Sender: owner-linux-mm@kvack.org To: H.H.vanRiel@phys.uu.nl Cc: Billy.Harvey@thrillseeker.net, sct@redhat.com, linux-mm@kvack.org, linux-kernel@vger.rutgers.edu List-ID: On Tue, 8 Dec 1998 03:31:25 +0100 (CET), Rik van Riel writes: > On a swapout, we will scan ahead of where we are (p->swap_address) > and swap out the next number of pages too. We break the loop if: > - the page isn't present or already in swap > - the next two pages were touched since our last scan > - the page isn't allocated > - we reach the end of a SWAP_CLUSTER area in swap space > > If we write this way (no more expensive than normal because > we write the stuff in one disk movement) swapin readahead > will be much more effective and performance will increase. Except for disk I/O bound processes, where the swapout writeahead steals some extra time from the disk. I guess this is where having separate swap and data disks would help. Looking forward to trying out your patches myself. Drago -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org