From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <45F991E5.1060001@redhat.com> Date: Thu, 15 Mar 2007 14:35:17 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH] mm/filemap.c: unconditionally call mark_page_accessed References: <20070312142012.GH30777@atrey.karlin.mff.cuni.cz> <20070312143900.GB6016@wotan.suse.de> <20070312151355.GB23532@duck.suse.cz> <20070312173500.GF23532@duck.suse.cz> <20070313185554.GA5105@duck.suse.cz> <1173905741.8763.36.camel@kleikamp.austin.ibm.com> <20070314213317.GA22234@rhlx01.hs-esslingen.de> <200703151737.l2FHb81d001600@turing-police.cc.vt.edu> In-Reply-To: <200703151737.l2FHb81d001600@turing-police.cc.vt.edu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Valdis.Kletnieks@vt.edu Cc: Andreas Mohr , Dave Kleikamp , Ashif Harji , linux-mm@kvack.org, Nick Piggin , Jan Kara , linux-kernel@vger.kernel.org, akpm@linux-foundation.org List-ID: Valdis.Kletnieks@vt.edu wrote: > On Wed, 14 Mar 2007 22:33:17 BST, Andreas Mohr said: > >> it'd seem we need some kind of state management here to figure out good >> intervals of when to call mark_page_accessed() *again* for this page. E.g. >> despite non-changing access patterns you could still call mark_page_accessed( > ) >> every 32 calls or so to avoid expiry, but this would need extra helper >> variables. > > What if you did something like > > if (jiffies%32) {... > > (Possibly scaling it so the low-order bits change). No need to lock it, as > "right most of the time" is close enough. Bad idea. That way you would only count page accesses if the phase of the moon^Wjiffie is just right. -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic. -- 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