From: Eric Sandeen Subject: Re: [PATCH 1/2] fs-writeback: Add helper function to start writeback if idle Date: Fri, 18 Dec 2009 09:29:57 -0600 Message-ID: <4B2B9FF5.4030102@redhat.com> References: <4B22D029.5090304@redhat.com> <20091218114427.GQ4489@kernel.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: ext4 development , linux-fsdevel@vger.kernel.org To: Jens Axboe Return-path: In-Reply-To: <20091218114427.GQ4489@kernel.dk> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Jens Axboe wrote: > On Fri, Dec 11 2009, Eric Sandeen wrote: >> ext4, at least, would like to start pushing on writeback if it starts >> to get close to ENOSPC when reserving worst-case blocks for delalloc >> writes. Writing out delalloc data will convert those worst-case >> predictions into usually smaller actual usage, freeing up space >> before we hit ENOSPC based on this speculation. >> >> Thanks to Jens for the suggestion for the helper function, >> & the naming help. >> >> I've made the helper return status on whether writeback was >> started even though I don't plan to use it in the ext4 patch; >> it seems like it would be potentially useful to test this >> in some cases. > > Eric, how do you want to merge these? I can easily take this first one > through any branch, but I suppose the ext4 one should go through the > proper ext4 channels. Doesn't matter to me really; maybe it'd be simpler if it all went though the ext4 tree so that there aren't any ordering problems? -Eric