From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sander Subject: Re: Poor read performance on high-end server Date: Fri, 20 Aug 2010 06:53:44 +0200 Message-ID: <20100820045344.GB28712@attic.humilis.net> References: <4C5AC52D.9030906@sara.nl> <20100805145138.GJ29846@think> <4C5BF829.3020200@kernel.dk> <20100806115939.GC29846@think> Reply-To: sander@humilis.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: Chris Mason , Jens Axboe , Freek Dijkstra , linux-btrfs@vger.kernel.org Return-path: In-Reply-To: <20100806115939.GC29846@think> List-ID: Chris Mason wrote (ao): > On Fri, Aug 06, 2010 at 01:55:21PM +0200, Jens Axboe wrote: > > Also, I didn't see Chris mention this, but if you have a newer intel box > > you can use hw accellerated crc32c instead. For some reason my test box > > always loads crc32c and not crc32c-intel, so I need to do that manually. > > That helps a lot with higher transfer rates. You can check support for > > hw crc32c by checking for the 'sse4_2' flag in /proc/cpuinfo. > > Yeah, the HW assisted crc does make a huge difference. The above says "newer intel box". I did some googling and it seems to mean really Intel CPUs only, not AMD, correct? Is there a way to get hardware support for crc32c on ARM based systems? Sander -- Humilis IT Services and Solutions http://www.humilis.net