Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751586AbXALEqn (ORCPT ); Thu, 11 Jan 2007 23:46:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751588AbXALEqn (ORCPT ); Thu, 11 Jan 2007 23:46:43 -0500 Received: from smtp.osdl.org ([65.172.181.24]:60372 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751586AbXALEqm (ORCPT ); Thu, 11 Jan 2007 23:46:42 -0500 Date: Thu, 11 Jan 2007 20:46:01 -0800 (PST) From: Linus Torvalds To: Nick Piggin cc: Bill Davidsen , Andrew Morton , Hua Zhong , Hugh Dickins , linux-kernel@vger.kernel.org, hch@infradead.org, kenneth.w.chen@intel.com, mjt@tls.msk.ru Subject: Re: O_DIRECT question In-Reply-To: <45A70EF9.40408@yahoo.com.au> Message-ID: References: <6d6a94c50701101857v2af1e097xde69e592135e54ae@mail.gmail.com> <6d6a94c50701102150w4c3b46d0w6981267e2b873d37@mail.gmail.com> <20070110220603.f3685385.akpm@osdl.org> <6d6a94c50701102245g6afe6aacxfcb2136baee5cbfa@mail.gmail.com> <20070110225720.7a46e702.akpm@osdl.org> <45A5E1B2.2050908@yahoo.com.au> <6d6a94c50701102354l7ab41a3bp4761566204f1d992@mail.gmail.com> <45A5F157.9030001@yahoo.com.au> <45A6F70E.1050902@tmr.com> <45A70EF9.40408@yahoo.com.au> 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: 919 Lines: 24 On Fri, 12 Jan 2007, Nick Piggin wrote: > > We are talking about about fragmentation. And limiting pagecache to try to > avoid fragmentation is a bandaid, especially when the problem can be solved > (not just papered over, but solved) in userspace. It's not clear that the problem _can_ be solved in user space. It's easy enough to say "never allocate more than a page". But it's often not REALISTIC. Very basic issue: the perfect is the enemy of the good. Claiming that there is a "proper solution" is usually a total red herring. Quite often there isn't, and the "paper over" is actually not papering over, it's quite possibly the best solution there is. Linus - 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/