From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roland Dreier Subject: Re: Integration of SCST in the mainstream Linux kernel Date: Tue, 29 Jan 2008 13:31:52 -0800 Message-ID: References: <1201639331.3069.58.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from sj-iport-5.cisco.com ([171.68.10.87]:33597 "EHLO sj-iport-5.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752965AbYA2VcF (ORCPT ); Tue, 29 Jan 2008 16:32:05 -0500 In-Reply-To: <1201639331.3069.58.camel@localhost.localdomain> (James Bottomley's message of "Tue, 29 Jan 2008 15:42:11 -0500") Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: Bart Van Assche , Linus Torvalds , Andrew Morton , Vladislav Bolkhovitin , FUJITA Tomonori , linux-scsi@vger.kernel.org, scst-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org > . . STGT read SCST read . STGT read SCST read . > . . performance performance . performance performance . > . . (0.5K, MB/s) (0.5K, MB/s) . (1 MB, MB/s) (1 MB, MB/s) . > . iSER (8 Gb/s network) . 250 N/A . 360 N/A . > . SRP (8 Gb/s network) . N/A 421 . N/A 683 . > On the comparable figures, which only seem to be IPoIB they're showing a > 13-18% variance, aren't they? Which isn't an incredible difference. Maybe I'm all wet, but I think iSER vs. SRP should be roughly comparable. The exact formatting of various messages etc. is different but the data path using RDMA is pretty much identical. So the big difference between STGT iSER and SCST SRP hints at some big difference in the efficiency of the two implementations. - R.