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 BAA14808 for ; Wed, 13 Jan 1999 01:52:27 -0500 Subject: Re: MM deadlock [was: Re: arca-vm-8...] References: Reply-To: Zlatko.Calusic@CARNet.hr MIME-Version: 1.0 From: Zlatko Calusic Date: 13 Jan 1999 07:52:09 +0100 In-Reply-To: Rik van Riel's message of "Tue, 12 Jan 1999 22:46:08 +0100 (CET)" Message-ID: <877lurbr6u.fsf@atlas.CARNet.hr> Sender: owner-linux-mm@kvack.org To: Rik van Riel Cc: Linus Torvalds , "Stephen C. Tweedie" , "Eric W. Biederman" , Savochkin Andrey Vladimirovich , Andrea Arcangeli , steve@netplus.net, brent verner , "Garst R. Reese" , Kalle Andersson , Ben McCann , Alan Cox , bredelin@ucsd.edu, linux-kernel@vger.rutgers.edu, linux-mm@kvack.org List-ID: Rik van Riel writes: > On 12 Jan 1999, Zlatko Calusic wrote: > > > After number of async pages gets bigger than > > pager_daemon.swap_cluster (= SWAP_CLUSTER_MAX), swapin readahead > > becomes synchronous, and that hurts performance. It is better to > > skip readahead in such situations, and that is also more fair to > > swapout. Andrea came to exactly the same conclusion, independent > > of me (on the same day :)). > > IIRC this facility was in the original swapin readahead > implementation. That only leaves the question who removed > it and why :)) > *I* did, because original test was too complicated and nobody understood what was it actual purpose. Beside that, when MM code changed recently, nr_free_pages started hovering at lower values, and that was killing readahead at most cases (with old test in place), thus producing terrible results, especially when you had more than one thrashing task. -- Zlatko -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org