From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54494) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XINuB-0007SA-Nc for qemu-devel@nongnu.org; Fri, 15 Aug 2014 16:15:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XINu2-0008JY-MQ for qemu-devel@nongnu.org; Fri, 15 Aug 2014 16:15:19 -0400 Received: from mail-wi0-x231.google.com ([2a00:1450:400c:c05::231]:56215) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XINu2-0008JR-FY for qemu-devel@nongnu.org; Fri, 15 Aug 2014 16:15:10 -0400 Received: by mail-wi0-f177.google.com with SMTP id ho1so1270870wib.10 for ; Fri, 15 Aug 2014 13:15:09 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <53EE6A45.9010400@redhat.com> Date: Fri, 15 Aug 2014 22:15:01 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1407209598-2572-1-git-send-email-ming.lei@canonical.com> <20140805094844.GF4391@noname.str.redhat.com> <20140805134815.GD12251@stefanha-thinkpad.redhat.com> <20140805144728.GH4391@noname.str.redhat.com> <20140806084855.GA4090@noname.str.redhat.com> <20140810114624.0305b7af@tom-ThinkPad-T410> <53E91B5D.4090009@redhat.com> <20140814104637.GB3820@noname.redhat.com> In-Reply-To: <20140814104637.GB3820@noname.redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH v1 00/17] dataplane: optimization and multi virtqueue support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: tom.leiming@gmail.com, Ming Lei , Fam Zheng , qemu-devel , Stefan Hajnoczi Il 14/08/2014 12:46, Kevin Wolf ha scritto: > So to finally reply with some numbers... I'm running fio tests based on > Ming's configuration on a loop-mounted tmpfs image using dataplane. I'm not sure tmpfs is a particularly useful comparison, since it doesn't support O_DIRECT. O_DIRECT over ramdisk ("modprobe brd rd_nr=1 rd_size=524288 max_part=1", either directly or via a filesystem) is probably a better benchmark. Also, I'm not sure how the I/O scheduler works over tmpfs. A ramdisk should just do the right thing. (Are you using deadline or cfq?) > | Random throughput | Sequential throughput > ----------------+-------------------+----------------------- > master | 442 MB/s | 730 MB/s > base | 453 MB/s | 757 MB/s > bypass (Ming) | 461 MB/s | 734 MB/s > coroutine | 468 MB/s | 716 MB/s > bypass (Paolo) | 476 MB/s | 682 MB/s This is pretty large, but it really smells like either a setup problem or a kernel bug... Paolo