From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 29 Apr 2001 09:41:21 -0400 From: Arjan van de Ven Subject: Re: RFC: Bouncebuffer fixes Message-ID: <20010429094121.B3131@devserv.devel.redhat.com> References: <20010428170648.A10582@devserv.devel.redhat.com> <20010429020757.C816@athlon.random> <20010429035626.B14210@devserv.devel.redhat.com> <20010429151711.A11395@athlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20010429151711.A11395@athlon.random>; from andrea@suse.de on Sun, Apr 29, 2001 at 03:17:11PM +0200 Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: Arjan van de Ven , linux-mm@kvack.org, alan@lxorguk.ukuu.org.uk, Linus Torvalds List-ID: On Sun, Apr 29, 2001 at 03:17:11PM +0200, Andrea Arcangeli wrote: > GFP_BUFFER doesn't provide guarantee of progress and that's fine, as far > as GFP_BUFFER allocations returns NULL eventually there should be no > problem. The fact some emergency buffer is in flight is just the guarantee > of progress because after unplugging tq_disk we know those emergency > buffers will be released without the need of further memory allocations. This is NOT what is happening. Look at the code. It does a GFP_BUFFER allocation before even attempting to use the bounce-buffers! So there is no guarantee of having emergency bouncebuffers in flight. Also, I'm not totally convinced that GFP_BUFFER will never sleep before running the tq_disk, but I agree that that can qualify as a seprate bug. Greetings, Arjan van de Ven -- 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.eu.org/Linux-MM/