Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754642AbbKMLhZ (ORCPT ); Fri, 13 Nov 2015 06:37:25 -0500 Received: from mail-yk0-f170.google.com ([209.85.160.170]:36638 "EHLO mail-yk0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754650AbbKMLhW (ORCPT ); Fri, 13 Nov 2015 06:37:22 -0500 MIME-Version: 1.0 In-Reply-To: <4015766.7tjD0ocbRK@wuerfel> References: <20151112125901.GD27454@quack.suse.cz> <4015766.7tjD0ocbRK@wuerfel> Date: Fri, 13 Nov 2015 19:37:21 +0800 Message-ID: Subject: Re: [PATCH 0/2] Introduce the request handling for dm-crypt From: Baolin Wang To: Arnd Bergmann Cc: Jan Kara , Christoph Hellwig , Jens Axboe , Alasdair G Kergon , Mike Snitzer , dm-devel@redhat.com, neilb@suse.com, tj@kernel.org, jmoyer@redhat.com, keith.busch@intel.com, bart.vanassche@sandisk.com, linux-raid@vger.kernel.org, Mark Brown , "Garg, Dinesh" , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1605 Lines: 45 On 13 November 2015 at 17:05, Arnd Bergmann wrote: > On Friday 13 November 2015 10:05:28 Baolin Wang wrote: >> >> Well, I did a simple test with dd reading, cause my engine limitation is 1M, >> (1) so the time like below when handle 1M at one time. >> 1048576 bytes (1.0 MB) copied, 0.0841235 s, 12.5 MB/s >> 1048576 bytes (1.0 MB) copied, 0.0836294 s, 12.5 MB/s >> 1048576 bytes (1.0 MB) copied, 0.0836526 s, 12.5 MB/s >> >> (2) These handle 64K at one time * 16 times >> 1048576 bytes (1.0 MB) copied, 0.0937223 s, 11.2 MB/s >> 1048576 bytes (1.0 MB) copied, 0.097205 s, 10.8 MB/s >> 1048576 bytes (1.0 MB) copied, 0.0935884 s, 11.2 MB/s >> >> Here is a 10ms level difference, try to image if the hardware engine's >> throughput is bigger than that. But like Jens said, we can measure it >> by the performance data. > > The absolute numbers look really low. Does this include writing to > a hard drive? That would certainly make the difference appear > less significant. > OK, I'll supply the complete performance data to measure it. > Could you try backing this with a ram disk backing for comparison, > and also use 'time dd' to show the CPU utilization for all cases? > For completeness, including cpu-only performance might also help > put this into perspective. > OK, I'll try. Thanks. > Arnd -- Baolin.wang Best Regards -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/