From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from neon.transmeta.com (neon-best.transmeta.com [206.184.214.10]) by kvack.org (8.8.7/8.8.7) with ESMTP id BAA09927 for ; Sat, 9 Jan 1999 01:46:00 -0500 Date: Fri, 8 Jan 1999 22:44:25 -0800 (PST) From: Linus Torvalds Subject: Re: 2.2.0-pre[56] swap performance poor with > 1 thrashing task In-Reply-To: <87sodl552m.fsf@atlas.CARNet.hr> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Zlatko Calusic Cc: Dax Kelson , Steve Bergman , Andrea Arcangeli , brent verner , "Garst R. Reese" , Kalle Andersson , Ben McCann , bredelin@ucsd.edu, linux-kernel@vger.rutgers.edu, linux-mm@kvack.org, Alan Cox , "Stephen C. Tweedie" List-ID: Btw, if there are people there who actually like timing different things (something I _hate_ doing - I lose interest if things become just a matter of numbers rather than trying to get some algorithm right), then there's one thing I'd love to hear about: the effect of trying to do some access bit setting on buffer cache pages. See my comments in linux/include/linux/fs.h, at around line 260 or so. It's the "touch_buffer()" macro which is currently a no-op, and it is entirely possible that it really should set the PG_referenced bit. As a no-op, it can now randomly and unprectably result in even worthwhile buffers just being thrown out - possibly quite soon after they've been loaded in. I happen to believe that it doesn't actually matter (and I'm not convinced that marking the pages referenced has no downsides), but I'm too lazy to bother to test it. Linus -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org