From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomas Henzl Subject: Re: [PATCH 04/11] megaraid_sas : Firmware crash dump feature support Date: Wed, 10 Sep 2014 17:28:40 +0200 Message-ID: <54106E28.1030807@redhat.com> References: <201409061328.s86DS6lO012975@palmhbs0.lsi.com> <540F22A2.3040906@redhat.com> <55ba5d7cdee7dbcce18dc1a2bbbefc03@mail.gmail.com> <94D0CD8314A33A4D9D801C0FE68B402958C70F51@G9W0745.americas.hpqcorp.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mx1.redhat.com ([209.132.183.28]:51112 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752306AbaIJPba (ORCPT ); Wed, 10 Sep 2014 11:31:30 -0400 In-Reply-To: <94D0CD8314A33A4D9D801C0FE68B402958C70F51@G9W0745.americas.hpqcorp.net> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Elliott, Robert (Server Storage)" , Sumit Saxena , "linux-scsi@vger.kernel.org" Cc: "martin.petersen@oracle.com" , "hch@infradead.org" , "jbottomley@parallels.com" , Kashyap Desai , "aradford@gmail.com" , Michal Schmidt , "amirv@mellanox.com" , "vgoyal@redhat.com" , "Jens Axboe (axboe@kernel.dk)" , "scameron@beardog.cce.hp.com" On 09/10/2014 05:06 PM, Elliott, Robert (Server Storage) wrote: >> From: linux-scsi-owner@vger.kernel.org [mailto:linux-scsi- >> owner@vger.kernel.org] On Behalf Of Sumit Saxena >> >>> From: Tomas Henzl [mailto:thenzl@redhat.com] >>> >>> With several controllers in a system this may take a lot memory, >>> could you also in case when a kdump kernel is running lower it, >>> by not using this feature? >>> >> Agreed, we will disable this feature for kdump kernel by adding >> "reset_devices" global varaiable. >> That check is required for only one place, throughout the code, this >> feature will remain disabled. Code snippet for the same- >> >> instance->crash_dump_drv_support =3D (!reset_devices) && >> crashdump_enable && >> instance->crash_dump_fw_support && >> instance->crash_dump_buf); >> if(instance->crash_dump_drv_support) { >> printk(KERN_INFO "megaraid_sas: FW Crash dump is >> supported\n"); >> megasas_set_crash_dump_params(instance, >> MR_CRASH_BUF_TURN_OFF); >> >> } else { >> .. >> } > Network drivers have been running into similar problems. > > There's a new patch from Amir coming through net-next to make=20 > is_kdump_kernel() (in crash_dump.h) accessible to modules. > That may be a better signal than reset_devices that the > driver should use minimal resources. > > http://comments.gmane.org/gmane.linux.network/324737 > > I'm not sure about the logistics of a SCSI patch depending > on a net-next patch. Probably better to start with reset_devices and switch to is_kdump_kern= el() later.=20 This is not a discussion about reset_devices versus is_kdump_kernel, bu= t while it looks good to have it distinguished - is the reset_devices act= ually used anywhere else than in kdump kernel? =20 > > --- > Rob Elliott HP Server Storage > > > > > N=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BDr=EF=BF=BD=EF=BF=BDy=EF= =BF=BD=EF=BF=BD=EF=BF=BDb=EF=BF=BDX=EF=BF=BD=EF=BF=BD=C7=A7v=EF=BF=BD^=EF= =BF=BD)=DE=BA{.n=EF=BF=BD+=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD{=EF=BF=BD= =EF=BF=BD=EF=BF=BD"=EF=BF=BD{ay=EF=BF=BD=1D=CA=87=DA=99=EF=BF=BD,j=07=EF= =BF=BD=EF=BF=BDf=EF=BF=BD=EF=BF=BD=EF=BF=BDh=EF=BF=BD=EF=BF=BD=EF=BF=BD= z=EF=BF=BD=1E=EF=BF=BDw=EF=BF=BD=EF=BF=BD=EF=BF=BD=0C=EF=BF=BD=EF=BF=BD= =EF=BF=BDj:+v=EF=BF=BD=EF=BF=BD=EF=BF=BDw=EF=BF=BDj=EF=BF=BDm=EF=BF=BD=EF= =BF=BD=EF=BF=BD=EF=BF=BD=07=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BDzZ+=EF=BF= =BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=DD=A2j"=EF=BF=BD=EF=BF=BD!tml=3D -- 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