From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: [PATCH/RESEND] scsi.mq: Added use_cmd_list flag in scsi_host to reduce lock contention Date: Wed, 20 Aug 2014 11:47:02 -0400 Message-ID: References: <201408201357.s7KDvDeL021549@palmhbs0.lsi.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:47541 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750819AbaHTPro (ORCPT ); Wed, 20 Aug 2014 11:47:44 -0400 In-Reply-To: <201408201357.s7KDvDeL021549@palmhbs0.lsi.com> (Kashyap Desai's message of "Wed, 20 Aug 2014 19:24:33 +0530") Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Kashyap.Desai@avagotech.com Cc: linux-scsi@vger.kernel.org, hch@infradead.org, elliott@hp.com, jbottomley@parallels.com, aacraid@adaptec.com, bvanassche@acm.org >>>>> "Kashyap" == writes: Kashyap> Comment provided by Bart Van and Chris H is addressed in this Kashyap> patch. Add use_cmd_list flag in scsi_host to indicate scs.mq Kashyap> stack to keep track of cmd_list per sdev. Kashyap> Default behaviour is not to keep track of cmd_list per sdev, as Kashyap> this may introduce lock contention. (overhead is more on Kashyap> multi-node NUMA.) Kashyap> Patch is tested using megaraid_sas driver with "use_cmd_list" Kashyap> value set to 1 and 0. Added MAINTAINER of Adaptec to verify Kashyap> changes. Kashyap> Signed-off-by: Kashyap Desai Looks good to me. Reviewed-by: Martin K. Petersen -- Martin K. Petersen Oracle Linux Engineering