From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <487F89AE.9070007@redhat.com> Date: Thu, 17 Jul 2008 14:04:30 -0400 From: Chris Snook MIME-Version: 1.0 Subject: Re: madvise(2) MADV_SEQUENTIAL behavior References: <1216163022.3443.156.camel@zenigma> <487E628A.3050207@redhat.com> <1216252910.3443.247.camel@zenigma> <200807171614.29594.nickpiggin@yahoo.com.au> <20080717102148.6bc52e94@cuia.bos.redhat.com> In-Reply-To: <20080717102148.6bc52e94@cuia.bos.redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: Nick Piggin , Eric Rannaud , Peter Zijlstra , linux-kernel@vger.kernel.org, linux-mm , Andrew Morton List-ID: Rik van Riel wrote: > On Thu, 17 Jul 2008 16:14:29 +1000 > Nick Piggin wrote: > >>> It might encourage user space applications to start using >>> FADV_SEQUENTIAL or FADV_NOREUSE more often (as it would become >>> worthwhile to do so), and if they do (especially cron jobs), the problem >>> of the slow desktop in the morning would progressively solve itself. >> The slow desktop in the morning should not happen even without such a >> call, because the kernel should not throw out frequently used data (even >> if it is not quite so recent) in favour of streaming data. >> >> OK, I figure it doesn't do such a good job now, which is sad, > > Do you have any tests in mind that we could use to decide > whether the patch I posted Tuesday would do a decent job > at protecting frequently used data from streaming data? > > http://lkml.org/lkml/2008/7/15/465 > 1) start up a memory-hogging Java app 2) run a full-system backup If it works well, the Java app shouldn't slow down much. -- Chris -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org