Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261216AbVEDRzg (ORCPT ); Wed, 4 May 2005 13:55:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261176AbVEDRzf (ORCPT ); Wed, 4 May 2005 13:55:35 -0400 Received: from mx1.redhat.com ([66.187.233.31]:26810 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S261228AbVEDRyy (ORCPT ); Wed, 4 May 2005 13:54:54 -0400 Date: Wed, 4 May 2005 13:54:48 -0400 (EDT) From: Rik van Riel X-X-Sender: riel@chimarrao.boston.redhat.com To: Nikita Danilov cc: linux-kernel@vger.kernel.org Subject: Re: [RFC] cleanup of use-once In-Reply-To: <17015.26421.403622.767581@gargle.gargle.HOWL> Message-ID: References: <17015.26421.403622.767581@gargle.gargle.HOWL> 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 Content-Length: 1336 Lines: 36 On Tue, 3 May 2005, Nikita Danilov wrote: > So file system pages never get to the active list? Hmm... this doesn't > sound right. Yes they will, I changed vmscan.c to compensate. > > + if (referenced) { > > + /* New page. Let's see if it'll get used again... */ > > + if (TestClearPageNew(page)) > > + goto keep_locked; > > goto activate_locked; > > + } > > This will screw scanning most likely: no referenced page is ever > reclaimed unless lowest scanning priority is reached---this looks like > sure way to oom and has capacity to increase CPU consumption > significantly. Doubtful, the VM always manages to clear the referenced bits faster than they can be set, especially on pages that aren't even mapped! The problem you describe should be a lot worse for mapped pages, where we already do not run into the problem, despite the VM taking no precautions. -- "Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." - Brian W. Kernighan - 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/