From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakob Oestergaard Subject: Re: [PATCH 00/19] Hardware Accelerated MD RAID5: Introduction Date: Thu, 14 Sep 2006 09:42:48 +0200 Message-ID: <20060914074248.GD23492@unthought.net> References: <1158015632.4241.31.camel@dwillia2-linux.ch.intel.com> <20060913071512.GA23492@unthought.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Dan Williams Cc: Dan Williams , NeilBrown , linux-raid@vger.kernel.org, akpm@osdl.org, linux-kernel@vger.kernel.org, christopher.leech@intel.com List-Id: linux-raid.ids On Wed, Sep 13, 2006 at 12:17:55PM -0700, Dan Williams wrote: ... > >Out of curiosity; how does accelerated compare to non-accelerated? > > One quick example: > 4-disk SATA array rebuild on iop321 without acceleration - 'top' > reports md0_resync and md0_raid5 dueling for the CPU each at ~50% > utilization. > > With acceleration - 'top' reports md0_resync cpu utilization at ~90% > with the rest split between md0_raid5 and md0_raid5_ops. > > The sync speed reported by /proc/mdstat is ~40% higher in the accelerated > case. Ok, nice :) > > That being said, array resync is a special case, so your mileage may > vary with other applications. Every-day usage I/O performance data would be nice indeed :) > I will put together some data from bonnie++, iozone, maybe contest, > and post it on SourceForge. Great! -- / jakob