From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Smart Subject: Re: [PATCH 1/1] be2iscsi: Fixes for powerpc compile Date: Fri, 11 Sep 2009 08:15:42 -0400 Message-ID: <4AAA3F6E.5030405@emulex.com> References: <20090910175417.3c24eb4b@mailhost.serverengines.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from emulex.emulex.com ([138.239.112.1]:44380 "EHLO emulex.emulex.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751930AbZIKMQD (ORCPT ); Fri, 11 Sep 2009 08:16:03 -0400 In-Reply-To: <20090910175417.3c24eb4b@mailhost.serverengines.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Jayamohan Kalickal Cc: James Bottomley , Mike Christie , "linux-scsi@vger.kernel.org" , "sfr@canb.auug.org.au" Jayamohan Kalickal wrote: > Ok. Reading Mike's comment once again and looking at the lpfc code ,I think, maybe, this is what Mike had in mind, but I could have misunderstood. > > During session create, I will create the pool as well as alloc. This will take > care of the allocation at page level and scarce coherent resources problems > mentioned by JamesB. Also, this would not have any impact on performance. I see this > done for "lpfc_mbuf_pool" in lpfc/lpfc_mem.c. > > Thanks > Jay As most things - it depends on what's being allocated. I recommended against a pci pool when I was looking at the allocations for queue memory, SGLs, etc as that is largely static (allocate/assign once, rarely dealloc/deassign) and very much likes to be 4k pages, page aligned, and as contiguous as possible. However, the DMA buffers for the Command and Response buffers is a different story. They are in the fast path, re-alloc per command, are smaller than a page, etc and fit the pci pool profile very well. -- james s