From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 1 Feb 2007 22:17:34 -0800 (PST) From: Christoph Lameter Subject: Re: [RFC 0/8] Cpuset aware writeback In-Reply-To: <17858.54239.364738.88727@notabene.brown> Message-ID: References: <20070116054743.15358.77287.sendpatchset@schroedinger.engr.sgi.com> <45C2960B.9070907@google.com> <20070201200358.89dd2991.akpm@osdl.org> <17858.54239.364738.88727@notabene.brown> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Neil Brown Cc: Andrew Morton , Ethan Solomita , Paul Menage , linux-kernel@vger.kernel.org, Nick Piggin , linux-mm@kvack.org, Andi Kleen , Paul Jackson , Dave Chinner List-ID: On Fri, 2 Feb 2007, Neil Brown wrote: > md/raid doesn't cause any problems here. It preallocates enough to be > sure that it can always make forward progress. In general the entire > block layer from generic_make_request down can always successfully > write a block out in a reasonable amount of time without requiring > kmalloc to succeed (with obvious exceptions like loop and nbd which go > back up to a higher layer). Hmmm... I wonder if that could be generalized. A device driver could make a reservation by increasing min_free_kbytes? Additional drivers in a chain could make additional reservations in such a way that enough memory is set aside for the worst case? > The network stack is of course a different (much harder) problem. An NFS solution is possible without solving the network stack issue? -- 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