From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH 3/3 v2] mm: Avoid resetting wb_start after each writeback round Date: Thu, 5 Aug 2010 21:38:39 +0200 Message-ID: <4C5B133F.60109@fusionio.com> References: <1281034399-13055-1-git-send-email-jack@suse.cz> <1281034399-13055-4-git-send-email-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Cc: Andrew Morton , "linux-fsdevel@vger.kernel.org" , "hch@infradead.org" , Wu Fengguang To: Jan Kara Return-path: Received: from mx2.fusionio.com ([64.244.102.31]:33988 "EHLO mx2.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752491Ab0HETir (ORCPT ); Thu, 5 Aug 2010 15:38:47 -0400 In-Reply-To: <1281034399-13055-4-git-send-email-jack@suse.cz> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 08/05/2010 08:53 PM, Jan Kara wrote: > WB_SYNC_NONE writeback is done in rounds of 1024 pages so that we don't write > out some huge inode for too long while starving writeout of other inodes. To > avoid livelocks, we record time we started writeback in wbc->wb_start and do > not write out inodes which were dirtied after this time. But currently, > writeback_inodes_wb() resets wb_start each time it is called thus effectively > invalidating this logic and making any WB_SYNC_NONE writeback prone to > livelocks. > > This patch makes sure wb_start is set only once when we start writeback. Acked-by: Jens Axboe -- Jens Axboe Confidentiality Notice: This e-mail message, its contents and any attachments to it are confidential to the intended recipient, and may contain information that is privileged and/or exempt from disclosure under applicable law. If you are not the intended recipient, please immediately notify the sender and destroy the original e-mail message and any attachments (and any copies that may have been made) from your system or otherwise. Any unauthorized use, copying, disclosure or distribution of this information is strictly prohibited.