From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from atlas.CARNet.hr (zcalusic@atlas.CARNet.hr [161.53.123.163]) by kvack.org (8.8.7/8.8.7) with ESMTP id QAA00836 for ; Wed, 2 Dec 1998 16:19:15 -0500 Subject: Re: [PATCH] swapin readahead References: <87vhjvkccu.fsf@atlas.CARNet.hr> <199812021735.RAA04489@dax.scot.redhat.com> Reply-To: Zlatko.Calusic@CARNet.hr Mime-Version: 1.0 From: Zlatko Calusic Date: 02 Dec 1998 22:18:58 +0100 In-Reply-To: "Stephen C. Tweedie"'s message of "Wed, 2 Dec 1998 17:35:26 GMT" Message-ID: <87d862gs3h.fsf@atlas.CARNet.hr> Sender: owner-linux-mm@kvack.org To: "Stephen C. Tweedie" Cc: Rik van Riel , Linux MM List-ID: "Stephen C. Tweedie" writes: > Hi, > > On Tue, 1 Dec 1998 19:32:52 +0100 (CET), Rik van Riel > said: > > > I took the bet that shrink_mmap() would take care of that, but > > aperrantly not always :( > > shrink_mmap() only gets rid of otherwise unused pages (pages whose count > is one). After read_swap_cache_async(), the page count will be three: > once for the swap cache, once for the io in progress, once for the > reference returned by read_swap_cache_async(). You need to free that > last reference explicitly after doing the readahead call. The io > reference will be returned once IO completes, and shrink_mmap() will > take care of the final swap cache reference. > That is exactly what I had in mind, but didn't have time to investigate further. Nor courage to say that, without trying first. :) I've been hacking shrink_mmap() and swap_out() most of the time last few days and in fact completely understood all inner workings of them. Quite complicated stuff, now I see why it so easily breaks if we change something aruond. Trying 2.1.131-2, I'm mostly satisfied with MM workout, but... Still, I have a feeling that limit imposed on cache growth is now too hard, unlike kernels from the 2.1.1[01]? era, that had opposite problems (excessive cache growth during voluminous I/O operations). What I wanted to ask is: do you guys share my opinion, and what changes would you like to see before 2.2 comes out? Thanks for any opinion. -- Posted by Zlatko Calusic E-mail: --------------------------------------------------------------------- "640K ought to be enough for anybody." Bill Gates '81 -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org