From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756379Ab0KKMxA (ORCPT ); Thu, 11 Nov 2010 07:53:00 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:38797 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756154Ab0KKMw7 (ORCPT ); Thu, 11 Nov 2010 07:52:59 -0500 Date: Thu, 11 Nov 2010 07:52:54 -0500 From: Christoph Hellwig To: Rusty Russell Cc: Christoph Hellwig , Dave Chinner , mst@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [2.6.37-rc1, OOM] virtblk: OOM in do_virtblk_request() Message-ID: <20101111125254.GB11194@infradead.org> References: <20101105013003.GE13830@dastard> <20101110133151.GB2101@infradead.org> <201011111116.48263.rusty@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201011111116.48263.rusty@rustcorp.com.au> User-Agent: Mutt/1.5.21 (2010-09-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 11, 2010 at 11:16:48AM +1030, Rusty Russell wrote: > On Thu, 11 Nov 2010 12:01:51 am Christoph Hellwig wrote: > > Rusty, Michael, > > > > any comments? I think Dave's observation is correct, and the lack of > > a mempool for allocations in the virtio stack is a no-go for virtio_blk. > > Interesting. virtio will try to fall back to using direct ring entries > if it can, but if course if your request is too large it can never do that. > > So, we could add a memory pool, or restrict the request size in virtio_blk. The mempool looks like the more generic solution. Especially as people are still talking about swap over nfs, at which point virtio-net will show the same issue (just even harder to reproduce)