From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760904AbXGKI4b (ORCPT ); Wed, 11 Jul 2007 04:56:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755939AbXGKI4Y (ORCPT ); Wed, 11 Jul 2007 04:56:24 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:55175 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754453AbXGKI4X (ORCPT ); Wed, 11 Jul 2007 04:56:23 -0400 Date: Wed, 11 Jul 2007 09:55:39 +0100 From: Christoph Hellwig To: Dave McCracken Cc: Nick Piggin , Mel Gorman , Andrew Morton , kenchen@google.com, jschopp@austin.ibm.com, apw@shadowen.org, kamezawa.hiroyu@jp.fujitsu.com, a.p.zijlstra@chello.nl, y-goto@jp.fujitsu.com, clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: -mm merge plans -- anti-fragmentation Message-ID: <20070711085539.GA18038@infradead.org> Mail-Followup-To: Christoph Hellwig , Dave McCracken , Nick Piggin , Mel Gorman , Andrew Morton , kenchen@google.com, jschopp@austin.ibm.com, apw@shadowen.org, kamezawa.hiroyu@jp.fujitsu.com, a.p.zijlstra@chello.nl, y-goto@jp.fujitsu.com, clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20070710102043.GA20303@skynet.ie> <200707100929.46153.dave.mccracken@oracle.com> <20070710152355.GI8779@wotan.suse.de> <200707101211.46003.dave.mccracken@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200707101211.46003.dave.mccracken@oracle.com> User-Agent: Mutt/1.4.2.3i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 10, 2007 at 12:11:45PM -0500, Dave McCracken wrote: > Ok, maybe disaster is too strong a word. But any kind of order>0 allocation > still has to be approached with fear and caution, with a well tested fallback > in the case of the inevitable failures. How many driver writers would have > benefited from using order>0 pages, but turned aside to other less optimal > solutions due to their unreliability? We don't know, and probably never > will. Those people have moved on and won't revisit that design decision. If you look at almost any other OS they use high-order pages quite a lot. At least Solaris, IRIX and UnixWare do. Also not that once we have a high-order pagecache it gives a nice way to simply reclaim a high-order page directly :) From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 11 Jul 2007 09:55:39 +0100 From: Christoph Hellwig Subject: Re: -mm merge plans -- anti-fragmentation Message-ID: <20070711085539.GA18038@infradead.org> References: <20070710102043.GA20303@skynet.ie> <200707100929.46153.dave.mccracken@oracle.com> <20070710152355.GI8779@wotan.suse.de> <200707101211.46003.dave.mccracken@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200707101211.46003.dave.mccracken@oracle.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Dave McCracken Cc: Nick Piggin , Mel Gorman , Andrew Morton , kenchen@google.com, jschopp@austin.ibm.com, apw@shadowen.org, kamezawa.hiroyu@jp.fujitsu.com, a.p.zijlstra@chello.nl, y-goto@jp.fujitsu.com, clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Tue, Jul 10, 2007 at 12:11:45PM -0500, Dave McCracken wrote: > Ok, maybe disaster is too strong a word. But any kind of order>0 allocation > still has to be approached with fear and caution, with a well tested fallback > in the case of the inevitable failures. How many driver writers would have > benefited from using order>0 pages, but turned aside to other less optimal > solutions due to their unreliability? We don't know, and probably never > will. Those people have moved on and won't revisit that design decision. If you look at almost any other OS they use high-order pages quite a lot. At least Solaris, IRIX and UnixWare do. Also not that once we have a high-order pagecache it gives a nice way to simply reclaim a high-order page directly :) -- 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