From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: Re: [PATCH ] tcm_qla2xxx Add SCSI command jammer/discard capabilty to the tcm_qla2xxx module - revision2 Date: Thu, 12 Mar 2015 13:13:28 +0000 Message-ID: <5EE87F5E6631894E80EB1A63198F964D042063ED@SACMBXIP03.sdcorp.global.sandisk.com> References: <1069288785.13490592.1425785175883.JavaMail.zimbra@redhat.com> <54FC03FA.6000005@sandisk.com> <629323685.13531146.1425829095558.JavaMail.zimbra@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Return-path: Received: from mail-bl2on0069.outbound.protection.outlook.com ([65.55.169.69]:12000 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754159AbbCLNNd convert rfc822-to-8bit (ORCPT ); Thu, 12 Mar 2015 09:13:33 -0400 Content-Language: en-US Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Laurence Oberman Cc: Andy Grover , "linux-scsi@vger.kernel.org" , "nab@daterainc.com" , Laurence Oberman On 03/08/2015 11:38 AM, Laurence Oberman wrote: > Here is revision2 > > I added unlikely and removed messaging control as it not necessary and adds overhead. > > I use target LIO for all my storage array test targets and customer problem resolution here at Red Hat. > This patch resulted from a requirement to mimic behaviour of an expensive hardware jammer for a customer. > I have used this for some time with good success to simulate and reproduce latency and slow drain fabric issues and > for testing and validating error handling behaviour in the Emulex, Qlogic and other F/C drivers. > > Works by checking new parameter jam_host if its >= 0 and matches vha->host_no , jamming is enabled when jam_host >=0 > If parameter set to -1 (default) no jamming is enabled. > I decided to share the patch, in the hope it may be useful for others but I do understand this is a special use case. Hello Laurence, Thanks for reworking this patch quickly. This patch looks fine to me. The only remaining concern I have is that I'm wondering what the best place would be to add this functionality - the qla2xxx driver or the LIO core ? Bart.