From: Peter Zijlstra Subject: Re: [patch 1/5] mm: add nofail variants of kmalloc kcalloc and kzalloc Date: Wed, 25 Aug 2010 13:35:32 +0200 Message-ID: <1282736132.2605.3563.camel@laptop> References: <1282656558.2605.2742.camel@laptop> <4C73CA24.3060707@fusionio.com> <20100825112433.GB4453@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Cc: David Rientjes , Jens Axboe , Andrew Morton , Neil Brown , Alasdair G Kergon , Chris Mason , Steven Whitehouse , Jan Kara , Frederic Weisbecker , "linux-raid@vger.kernel.org" , "linux-btrfs@vger.kernel.org" , "cluster-devel@redhat.com" , "linux-ext4@vger.kernel.org" , "reiserfs-devel@vger.kernel.org" , "linux-kernel@vger.kernel.org" To: Ted Ts'o Return-path: Received: from bombadil.infradead.org ([18.85.46.34]:34903 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751181Ab0HYLfo convert rfc822-to-8bit (ORCPT ); Wed, 25 Aug 2010 07:35:44 -0400 In-Reply-To: <20100825112433.GB4453@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, 2010-08-25 at 07:24 -0400, Ted Ts'o wrote: > Part of the problem is that we have a few places in the kernel where > failure is really not an option --- or rather, if we're going to fail > while we're in the middle of doing a commit, our choices really are > (a) retry the loop in the jbd layer (which Andrew really doesn't > like), (b) keep our own private cache of free memory so we don't fail > and/or loop, (c) fail the file system and mark it read-only, or (d) > panic. d) do the allocation before you're committed to going fwd and can still fail and back out.