From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <48FA9EDA.4030802@redhat.com> Date: Sat, 18 Oct 2008 22:43:38 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: mm-more-likely-reclaim-madv_sequential-mappings.patch References: <20081015162232.f673fa59.akpm@linux-foundation.org> <200810181230.33688.nickpiggin@yahoo.com.au> <87fxmu41wt.fsf@saeurebad.de> <200810191321.25490.nickpiggin@yahoo.com.au> In-Reply-To: <200810191321.25490.nickpiggin@yahoo.com.au> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Johannes Weiner , Andrew Morton , linux-mm@kvack.org List-ID: Nick Piggin wrote: > > That's just handwaving. The patch still clears PG_referenced, which > is a shared resource, and it is wrong, conceptually. You can't argue > with that. > > I don't see an easy way around that. If the PG_referenced bit is set and the page is mapped, the code in vmscan.c will move the page to the active list. Even if the one pte mapping the page is in an MADV_SEQUENTIAL VMA, in which case we definately do not want to activate the page. Of course, if the PG_referenced came from a different access, things would be a different matter. Fixing the page fault code so that it does not set the PG_referenced bit would take care of that. -- 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