Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751577AbVLFDgr (ORCPT ); Mon, 5 Dec 2005 22:36:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751579AbVLFDgr (ORCPT ); Mon, 5 Dec 2005 22:36:47 -0500 Received: from smtp.osdl.org ([65.172.181.4]:41910 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751578AbVLFDgq (ORCPT ); Mon, 5 Dec 2005 22:36:46 -0500 Date: Tue, 6 Dec 2005 14:36:31 +1100 From: Andrew Morton To: Trond Myklebust Cc: theonetruekenny@yahoo.com, linux-kernel@vger.kernel.org Subject: Re: nfs unhappiness with memory pressure Message-Id: <20051206143631.08b4e8e6.akpm@osdl.org> In-Reply-To: <1133822367.8003.5.camel@lade.trondhjem.org> References: <20051205210442.17357.qmail@web34106.mail.mud.yahoo.com> <1133822367.8003.5.camel@lade.trondhjem.org> X-Mailer: Sylpheed version 1.0.0 (GTK+ 1.2.10; i386-vine-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1233 Lines: 27 Trond Myklebust wrote: > > Argh... Not sure entirely how to deal with that... We definitely don't > want the thing futzing around inside throttle_vm_writeout(), 'cos > writeout isn't going to happen while the socket blocks. > As far as the core VM is concerned, these pages are really "dirty", only it happens to be a different flavour of dirtiness. So perhaps we should continue to mark these pages as dirty and let NFS internally take care of which end of the wire they're dirty at. Presumably calling writepage() a second time won't be very useful. Or will it? Perhaps when NFS sees writepage against a PageDirty && PageUnstable page it can recognise that as a hint to kick off a server-side write. > ...OTOH, I'm not entirely sure we want to use GFP_ATOMIC and risk > bleeding the emergency pools dry: we also need those in order to receive > replies from the server. You can use (GFP_ATOMIC & !__GFP_HIGH) to avoid draining emergency pools. - 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/