From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: Re: [PATCH 13/17] scsi: push host_lock down into scsi_{host,target}_queue_ready Date: Thu, 06 Feb 2014 18:10:55 +0100 Message-ID: <52F3C21F.70409@acm.org> References: <20140205123930.150608699@bombadil.infradead.org> <20140205124021.286457268@bombadil.infradead.org> <1391705819.22335.8.camel@dabdike> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Return-path: Received: from smtp03.stone-is.org ([87.238.162.65]:36671 "EHLO smtpgw.stone-is.be" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1756363AbaBFRK7 (ORCPT ); Thu, 6 Feb 2014 12:10:59 -0500 In-Reply-To: <1391705819.22335.8.camel@dabdike> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley , Christoph Hellwig Cc: Jens Axboe , linux-scsi@vger.kernel.org On 02/06/14 17:56, James Bottomley wrote: > Could you benchmark this lot and show what the actual improvement is > just for this series, if any? I see a performance improvement of 12% with the SRP protocol for the SCSI core optimizations alone (I am still busy measuring the impact of the blk-mq conversion but I can already see that it is really significant). Please note that the performance impact depends a lot on the workload (number of LUNs per SCSI host e.g.) so maybe the workload I chose is not doing justice to Christoph's work. And it's also important to mention that with the workload I ran I was saturating the target system CPU (a quad core Intel i5). In other words, results might be better with a more powerful target system. Bart.