From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965100AbVKHBhM (ORCPT ); Mon, 7 Nov 2005 20:37:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965126AbVKHBhL (ORCPT ); Mon, 7 Nov 2005 20:37:11 -0500 Received: from smtp206.mail.sc5.yahoo.com ([216.136.129.96]:13665 "HELO smtp206.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S965100AbVKHBhK (ORCPT ); Mon, 7 Nov 2005 20:37:10 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=XD7rbOVjYkljVyTgUysd80Si8yAFkc6w8EJinMizl7LLsvYkPj/msJrG8/Jqyb9MDcdMF2hrUrCHVAeYz1XA4r1Kgw5DNLNh+faZM8cKzV8By2rCnT6ccnDB+I8Kf2CpnuY2OTYSSKLj1RyTQ5PUe4I8knLU1rjV3caWg2CteKk= ; Message-ID: <4370015A.8010402@yahoo.com.au> Date: Tue, 08 Nov 2005 12:37:30 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Neil Brown CC: Andrew Morton , dm-devel@redhat.com, heiko.carstens@de.ibm.com, linux-kernel@vger.kernel.org, aherrman@de.ibm.com, bunk@stusta.de, cplk@itee.uq.edu.au Subject: Re: [dm-devel] Re: [PATCH resubmit] do_mount: reduce stack consumption References: <20051104105026.GA12476@osiris.boeblingen.de.ibm.com> <20051104084829.714c5dbb.akpm@osdl.org> <20051104212742.GC9222@osiris.ibm.com> <20051104235500.GE5368@stusta.de> <20051104160851.3a7463ff.akpm@osdl.org> <20051104173721.597bd223.akpm@osdl.org> <17260.17661.523593.420313@cse.unsw.edu.au> <17262.40176.342746.634262@cse.unsw.edu.au> <20051107153706.2f3c8b67.akpm@osdl.org> <436FF20D.8030200@yahoo.com.au> <17263.63845.556511.171582@cse.unsw.edu.au> In-Reply-To: <17263.63845.556511.171582@cse.unsw.edu.au> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Neil Brown wrote: > On Tuesday November 8, nickpiggin@yahoo.com.au wrote: >>Possibly it could go into struct io_context? >> > > > My quick reading of the code says that we could have to > allocate the struct right there in generic_make_request, and I don't > think we can be certain that such an allocation will succeed. > > Code that uses io_context can limp along if it doesn't exist. > The new generic_make_request needs this bio_list to be present > or it cannot do it's job. > You can ask for the io context without having a request. However, there is nothing like a mempool for them so code really should be able to limp along without them. I guess it would be silly to require such an allocation to succeed here, because the block layer is pretty free of OOM deadlocks. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com