From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dax.scot.redhat.com (sct@dax.scot.redhat.com [195.89.149.242]) by kvack.org (8.8.7/8.8.7) with ESMTP id HAA10016 for ; Tue, 17 Nov 1998 07:06:43 -0500 Date: Tue, 17 Nov 1998 12:06:33 GMT Message-Id: <199811171206.MAA01194@dax.scot.redhat.com> From: "Stephen C. Tweedie" MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Subject: Re: unexpected paging during large file reads in 2.1.127 In-Reply-To: References: <199811162305.XAA07996@dax.scot.redhat.com> Sender: owner-linux-mm@kvack.org To: Rik van Riel Cc: "Stephen C. Tweedie" , Zlatko Calusic , "David J. Fred" , linux-kernel@vger.rutgers.edu, Linux-MM List List-ID: Hi, On Tue, 17 Nov 1998 07:42:12 +0100 (CET), Rik van Riel said: > I meant the page aging that occurs in vmscan.c, where we > decide on which page to unmap from a program's address > space. For the last time, NO IT DOES NOT. Read the source. Linus removed it. We do not use page->age AT ALL in vmscan.c in current 2.1 kernels. > There we do aging while we don't age pages from files that are read(). For the last time, YES WE DO. shrink_mmap() for the page cache in mm/filemap.c still uses page aging in current 2.1 kernels. Read() uses the page cache. This is a problem. > OK, I can (and have for quite a while) agree with this. > Kernels with this feature and enough memory will run great, > maybe small machines (<16M) will have a bit of trouble > keeping up readahead performance (since kswapd will have > made it's round a bit fast) but those machines will have > sucky performance anyway :) This change improves low memory performance very measurably in all tests I have tried so far. --Stephen. -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org