From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q5P973JM217449 for ; Mon, 25 Jun 2012 04:07:03 -0500 Received: from bombadil.infradead.org (173-166-109-252-newengland.hfc.comcastbusiness.net [173.166.109.252]) by cuda.sgi.com with ESMTP id Si1pPct7qERFgi9G (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Mon, 25 Jun 2012 02:06:59 -0700 (PDT) Date: Mon, 25 Jun 2012 05:06:58 -0400 From: Christoph Hellwig Subject: Re: [regression] stack overflow in xfs_buf_iodone_callbacks Message-ID: <20120625090657.GA22726@infradead.org> References: <20120621091803.GB10673@dastard> <20120621163409.GA7897@infradead.org> <20120621232414.GD10673@dastard> <20120622164147.GA20617@infradead.org> <20120622233955.GY19223@dastard> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20120622233955.GY19223@dastard> 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: Christoph Hellwig , xfs@oss.sgi.com On Sat, Jun 23, 2012 at 09:39:55AM +1000, Dave Chinner wrote: > Hmmmm. How often do we get real io completion occurring before we > call _xfs_buf_ioend() here? I can't see that it is common, so this > is probably fine, but perhaps a few numbers might help here? If it > is rare as we think it is, then yeah, that would work.... The only case where I can see it ever hapen is when sending tons of separate I/Os in one go to a reall fast device, e.g. a very fragmented large directory to superfast battery backed dram device. And even then I don't think it matters very much - for reads we generally do not have an b_iodone handler attached, so for these the change does not make any different. For delayed writes the additional context switch also doesn't have a major impact on performance, so the only thing where we could see a difference is synchronous writes, of which we don't have a lot left, and essentially none unless the shrinkers kick in and need to do synchronous reclaims. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs