From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurence Oberman Subject: Re: tcm_qla2xxx Add SCSI command jammer/discard capabilty to the tcm_qla2xxx module - revision3 Date: Thu, 31 Mar 2016 20:55:22 -0400 (EDT) Message-ID: <1409144622.26265222.1459472122250.JavaMail.zimbra@redhat.com> References: <2025450295.25603731.1459262558755.JavaMail.zimbra@redhat.com> <56FB5E98.9010103@sandisk.com> <1459402453.31390.45.camel@haakon3.risingtidesystems.com> <3F517A19-EDA5-4B16-B103-C3F38242F8D8@qlogic.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mx4-phx2.redhat.com ([209.132.183.25]:37278 "EHLO mx4-phx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757480AbcDAAz1 convert rfc822-to-8bit (ORCPT ); Thu, 31 Mar 2016 20:55:27 -0400 In-Reply-To: <3F517A19-EDA5-4B16-B103-C3F38242F8D8@qlogic.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Himanshu Madhani Cc: "Nicholas A. Bellinger" , Bart Van Assche , linux-scsi , target-devel , Quinn Tran Hello Himanshu Thanks, I will rework and post back to the thread. Thank you Laurence Oberman Principal Software Maintenance Engineer Red Hat Global Support Services ----- Original Message ----- =46rom: "Himanshu Madhani" To: "Nicholas A. Bellinger" , "Bart Van Assche" Cc: "Laurence Oberman" , "linux-scsi" , "target-devel" , "Quinn= Tran" Sent: Thursday, March 31, 2016 8:20:56 PM Subject: Re: tcm_qla2xxx Add SCSI command jammer/discard capabilty to t= he tcm_qla2xxx module - revision3 Hi Nic, Laurence,=20 On 3/30/16, 10:34 PM, "Nicholas A. Bellinger" wro= te: >(Adding target-devel + Qlogic target folks) > >On Tue, 2016-03-29 at 22:05 -0700, Bart Van Assche wrote: >> On 03/29/16 07:42, Laurence Oberman wrote: >> > I have been using this jammer functionality to continue testing th= e SCSI F/C drivers and recovery for over a year now. >> > Any chance you would agree to ack this so I can get it in now. >> > I last posted to the list last March and it was not picked up. >> > >> > I did look into moving this to upper layers but I find I use it pr= imarily for fiber channel target testing. >> > Attempting to add this functionality to upper layers led to comple= xities and this is very solid. >> > >> > This Patch diff against 4.5 >> > >> > I use target LIO for all my storage array test targets and custome= r problem resolution here at Red Hat. >> > This patch resulted from a requirement to mimic behavior of an exp= ensive hardware jammer for a customer. >> > I have used this for some time with good success to simulate and r= eproduce latency and slow drain fabric issues and >> > for testing and validating error handling behavior >> > in the Emulex, Qlogic and other F/C drivers. >> > >> > Works by checking new parameter jam_host if its >=3D 0 and matches= vha->host_no , jamming is enabled when jam_host >=3D0 >> > If parameter set to -1 (default) no jamming is enabled. >>=20 >> Hello Laurence, >>=20 >> Nic Bellinger is the maintainer of LIO so my recommendation is to as= k=20 >> Nic first about his opinion (I have CC'd Nic). I'm not sure what Nic= =20 >> thinks about this but in my opinion such functionality belongs in th= e=20 >> target core instead of in a target driver. But please wait until Nic= has=20 >> provided his opinion before spending more time on this. The mailing = list=20 >> for SCSI target patches is target-devel@vger.kernel.org. >>=20 > >So really it's Himanshu's + Quinn's call if they would like to include >something like this in mainline. > >If so, then I'd prefer to do it with a per tcm_qla2xxx_tpg endpoint >attribute instead a new module parameter, and add a new kernel config >option (CONFIG_TCM_QLA2XXX_DEBUG) to disable (by default) so end users >don't inadvertently play with it via targetcli + friends. > I agree here with Nic. The patch does provides benefit and is good addi= tion, but we don=E2=80=99t want to enable it by default. Laurence,=20 Would you be kind to rework patch with suggested changes from Nic and p= ost it.=20 Thanks,=20 Himanshu -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html