From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 30 Jul 2007 19:01:07 -0700 (PDT) From: Christoph Lameter Subject: Re: [rfc] [patch] mm: zone_reclaim fix for pseudo file systems In-Reply-To: <20070731015647.GC32468@localdomain> Message-ID: References: <20070727232753.GA10311@localdomain> <20070730132314.f6c8b4e1.akpm@linux-foundation.org> <20070731000138.GA32468@localdomain> <20070730172007.ddf7bdee.akpm@linux-foundation.org> <20070731015647.GC32468@localdomain> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Ravikiran G Thirumalai Cc: Andrew Morton , linux-mm@kvack.org, shai@scalex86.org List-ID: On Mon, 30 Jul 2007, Ravikiran G Thirumalai wrote: > On Mon, Jul 30, 2007 at 05:27:41PM -0700, Christoph Lameter wrote: > >On Mon, 30 Jul 2007, Andrew Morton wrote: > > > >> The problem is that __zone_reclaim() doesn't use all_unreclaimable at all. > >> You'll note that all the other callers of shrink_zone() do take avoiding > >> action if the zone is in all_unreclaimable state, but __zone_reclaim() forgot > >> to. > > > >zone reclaim only runs if there are unmapped file backed pages that can be > >reclaimed. > > Yes, and in this case, without the patch, VM considers RAMFS pages to be > file backed, thus being fooled into entering reclaim. The process entering > into reclaim in our tests gets in through zone_reclaim. That means RAMFS pages are accounted as NR_FILE_PAGES but not as NR_FILE_MAPPED..... So we have unmapped pages that are not reclaimable. But they are not really file backed pages. They are backed by memory. Can we just not increment NR_FILE_MAPPED? Should they not be accounted for an NR_ANON_PAGES or so? -- 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