From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from max.phys.uu.nl (max.phys.uu.nl [131.211.32.73]) by kvack.org (8.8.7/8.8.7) with ESMTP id RAA08081 for ; Thu, 23 Jul 1998 17:33:04 -0400 Date: Thu, 23 Jul 1998 21:51:37 +0200 (CEST) From: Rik van Riel Reply-To: Rik van Riel Subject: Re: More info: 2.1.108 page cache performance on low memory In-Reply-To: <87hg08vnmt.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: "Stephen C. Tweedie" , "Eric W. Biederman" , linux-mm@kvack.org List-ID: On 23 Jul 1998, Zlatko Calusic wrote: > One wrong way of fixing it is to limit page cache size, IMNSHO. > > I tried the other way, to age page cache harder, and it looks like it > works very well. Patch is simple, so simple that I can't understand > nobody suggested (something like) it yet. These solutions are somewhat the same, but your one may take a little less computational power and has a tradeoff in the fact that it is very inflexible. > --- filemap.c.virgin Tue Jul 21 18:41:30 1998 > +++ filemap.c Thu Jul 23 12:14:43 1998 > + age_page(page); > + age_page(page); > age_page(page); > If I put only two age_page()s, there's still too much swapping for my > taste. > With three age_page()s, read performance is as expected, and still we > manage memory more efficiently than without page aging. This only proves that three age_page()s are a good number for _your_ computer and your workload. > Comments? As Stephen put it so nicely when I (in a bad mood) proposed another artificial limit: " O no, another arbitrary limit in the kernel! " And another one of Stephen's wisdoms (heavily paraphrased!): " Good solutions are dynamic and/or self-tuning " [Sorry Stephen, this was VERY heavily paraphrased :)] Rik. +-------------------------------------------------------------------+ | Linux memory management tour guide. H.H.vanRiel@phys.uu.nl | | Scouting Vries cubscout leader. http://www.phys.uu.nl/~riel/ | +-------------------------------------------------------------------+ -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org