From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p49EDgc6012736 for ; Mon, 9 May 2011 09:13:42 -0500 Received: from bombadil.infradead.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id C59301E230C1 for ; Mon, 9 May 2011 07:13:41 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) by cuda.sgi.com with ESMTP id HnMxX276f431tLc0 for ; Mon, 09 May 2011 07:13:41 -0700 (PDT) Date: Mon, 9 May 2011 10:13:41 -0400 From: Christoph Hellwig Subject: Re: [PATCH 3/5] xfs: always push the AIL to the target Message-ID: <20110509141341.GD12262@infradead.org> References: <1304650448-28438-1-git-send-email-david@fromorbit.com> <1304650448-28438-4-git-send-email-david@fromorbit.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1304650448-28438-4-git-send-email-david@fromorbit.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: xfs@oss.sgi.com On Fri, May 06, 2011 at 12:54:06PM +1000, Dave Chinner wrote: > From: Dave Chinner > > The recent conversion of the xfsaild functionality to a work queue > introduced a hard-to-hit log space grant hang. One of the problems > discovered is a target mismatch between the item pushing loop and > the target itself. > > The push trigger checks for the target increasing (i.e. new target > > current) while the push loop only pushes items that have a LSN < > current. As a result, we can get the situation where the push target > is X, the items at the tail of the AIL have LSN X and they don't get > pushed. The push work then completes thinking it is done, and cannot > be restarted until the push target increases to >= X + 1. If the > push target then never increases (because the tail is not moving), > then we never run the push work again and we stall. > > Fix it by making sure log items with a LSN that matches the target > exactly are pushed during the loop. > > Signed-off-by: Dave Chinner Looks good, Reviewed-by: Christoph Hellwig _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs