X-Spam-Checker-Version: SpamAssassin 3.4.0-r929098 (2010-03-30) on oss.sgi.com X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham version=3.4.0-r929098 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 p7P5K7O7163656 for ; Thu, 25 Aug 2011 00:20:07 -0500 X-ASG-Debug-ID: 1314249606-396002490000-NocioJ X-Barracuda-URL: http://cuda.sgi.com:80/cgi-bin/mark.cgi Received: from bombadil.infradead.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id A3540111019 for ; Wed, 24 Aug 2011 22:20:06 -0700 (PDT) Received: from bombadil.infradead.org (173-166-109-252-newengland.hfc.comcastbusiness.net [173.166.109.252]) by cuda.sgi.com with ESMTP id 3VB7N1D6HbTDJHCF for ; Wed, 24 Aug 2011 22:20:06 -0700 (PDT) Received: from hch by bombadil.infradead.org with local (Exim 4.76 #1 (Red Hat Linux)) id 1QwSMG-0002GK-CA; Thu, 25 Aug 2011 05:20:04 +0000 Date: Thu, 25 Aug 2011 01:20:04 -0400 From: Christoph Hellwig To: Dave Chinner Cc: Christoph Hellwig , xfs@oss.sgi.com X-ASG-Orig-Subj: Re: [PATCH 2/3] xfs: use per-filesystem I/O completion workqueues Subject: Re: [PATCH 2/3] xfs: use per-filesystem I/O completion workqueues Message-ID: <20110825052004.GB5617@infradead.org> References: <20110824055924.139283426@bombadil.infradead.org> <20110824060150.001321834@bombadil.infradead.org> <20110825004811.GK3162@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110825004811.GK3162@dastard> User-Agent: Mutt/1.5.21 (2010-09-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html X-Barracuda-Connect: 173-166-109-252-newengland.hfc.comcastbusiness.net[173.166.109.252] X-Barracuda-Start-Time: 1314249606 X-Barracuda-Bayes: INNOCENT GLOBAL 0.0020 1.0000 -2.0078 X-Barracuda-Virus-Scanned: by cuda.sgi.com at sgi.com X-Barracuda-Spam-Score: -1.91 X-Barracuda-Spam-Status: No, SCORE=-1.91 using per-user scores of TAG_LEVEL=2.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=2.1 tests=RDNS_DYNAMIC X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.2.72759 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- 0.10 RDNS_DYNAMIC Delivered to trusted network by host with dynamic-looking rDNS X-Virus-Scanned: ClamAV version 0.94.2, clamav-milter version 0.94.2 on oss.sgi.com X-Virus-Status: Clean On Thu, Aug 25, 2011 at 10:48:11AM +1000, Dave Chinner wrote: > The only issue I see with this is that it brings back per-filesystem > workqueue threads. Because all the workqueues are defined with > MEM_RECLAIM, there is a rescuer thread per workqueue that is used > when the CWMQ cannot allocate memory to queue the work to the > appropriate per-cpu queue. Not much we can do about it. > If we are going to block here, then we probably should increase the > per-cpu concurrency of the work queue so that we can continue to > process other ioends while this one is blocked. True.