Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 16 Jul 2001 22:07:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 16 Jul 2001 22:07:12 -0400 Received: from web14304.mail.yahoo.com ([216.136.173.80]:24841 "HELO web14304.mail.yahoo.com") by vger.kernel.org with SMTP id ; Mon, 16 Jul 2001 22:06:59 -0400 Message-ID: <20010717020702.19729.qmail@web14304.mail.yahoo.com> Date: Mon, 16 Jul 2001 19:07:02 -0700 (PDT) From: Kanoj Sarcar Subject: Re: [PATCH] Separate global/perzone inactive/free shortage To: Marcelo Tosatti , Rik van Riel Cc: Kanoj Sarcar , lkml , Dirk Wetter , Mike Galbraith , linux-mm@kvack.org, "Stephen C. Tweedie" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --- Marcelo Tosatti wrote: > > On Mon, 16 Jul 2001, Rik van Riel wrote: > > > On Mon, 16 Jul 2001, Kanoj Sarcar wrote: > > > > > Just a quick note. A per-zone page reclamation > > > method like this was what I had advocated and > sent > > > patches to Linus for in the 2.3.43 time frame or > so. > > > I think later performance work ripped out that > work. > > > > Yes, the system ended up swapping as soon as the > first zone > > was filled up and after that would fill up the > other zones; > > the way the system stabilised was cycling through > the pages > > of one zone and leaving the lower zones alone. > > > > This reduced the amount of available VM of a 1GB > system > > to 128MB, which is somewhat suboptimal ;) > > > > What we learned from that is that we need to have > some > > way to auto-balance the reclaiming, keeping the > objective > > of evicting the least used page from RAM in mind. > > > > > I guess the problem is that a lot of the > different > > > page reclamation schemes first of all do not > know > > > how to reclaim pages for a specific zone, > > > > > try_to_swap_out is a good example, which can be > solved > > > by rmaps. > > > > Indeed. Most of the time things go right, but the > current > > system cannot cope at all when things go wrong. I > think we > > really want things like rmaps and more sturdy > reclaiming > > mechanisms to cope with these worst cases (and > also to make > > the common case easier to get right). > > As I said to Kanoj, I agree that we really want > rmaps to fix that thing > right. > > Now I don't see any other way for fixing that on > _2.4_ except something > similar to the patch I posted. That patch can still > have problems in > practice, but fundamentally _it is the right thing_, > IMO. Yes, I agree with you, and that is why I had sent the patch to Linus during 2.3 in the first place. What I am trying to point out is that you should talk to Rik, and understand why it was removed previously. Rik obviously had his reasons at that point, but some of those might not apply anymore, given that 2.4 is quite different from 2.3.43. Kanoj > > > -- > 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/ __________________________________________________ Do You Yahoo!? Get personalized email addresses from Yahoo! Mail http://personal.mail.yahoo.com/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/