From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Wise Subject: Re: [PATCH V6 6/9] isert: Rename IO functions to more descriptive names Date: Sun, 26 Jul 2015 15:15:34 -0500 Message-ID: <55B53FE6.1030509@opengridcomputing.com> References: <20150724161331.25617.8475.stgit@build2.ogc.int> <20150724161848.25617.26092.stgit@build2.ogc.int> <55B4B190.7070305@dev.mellanox.co.il> <20150726104328.GB18944@infradead.org> <55B4BDE3.8040801@dev.mellanox.co.il> <55B519C6.2030205@opengridcomputing.com> <55B51B7A.8030008@dev.mellanox.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <55B51B7A.8030008-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sagi Grimberg , Christoph Hellwig Cc: dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, infinipath-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, roid-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, eli-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, target-devel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org List-Id: linux-rdma@vger.kernel.org On 7/26/2015 12:40 PM, Sagi Grimberg wrote: > >>> Ideally, the post contains a chain of all 4 registrations and the >>> rdma_read (and an opportunistic good scsi response). >> >> Just to be clear: This example is for IB only, correct? IW would >> require rkeys with REMOTE_WRITE and 4 read wrs. > > My assumption is that it would depend on max_sge_rd. > yea. > IB only? iWARP by definition isn't capable of doing rdma_read to > more than one scatter? Anyway, we'll need to calculate the number > of RDMA_READs. > The wire protocol limits the destination to a single stg/to/len (aka rkey/addr/len). Devices/fw/sw could implement some magic to support a single stg/to/len that maps to a scatter gather list of stags/tos/lens. >> And you're ignoring invalidation wrs (or read-with-inv) in the >> example... > > Yes, didn't want to inflate the example too much... -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from linode.aoot.com ([69.164.194.13]:46250 "EHLO linode.aoot.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754550AbbGZUPi (ORCPT ); Sun, 26 Jul 2015 16:15:38 -0400 Subject: Re: [PATCH V6 6/9] isert: Rename IO functions to more descriptive names To: Sagi Grimberg , Christoph Hellwig References: <20150724161331.25617.8475.stgit@build2.ogc.int> <20150724161848.25617.26092.stgit@build2.ogc.int> <55B4B190.7070305@dev.mellanox.co.il> <20150726104328.GB18944@infradead.org> <55B4BDE3.8040801@dev.mellanox.co.il> <55B519C6.2030205@opengridcomputing.com> <55B51B7A.8030008@dev.mellanox.co.il> Cc: dledford@redhat.com, infinipath@intel.com, sagig@mellanox.com, ogerlitz@mellanox.com, roid@mellanox.com, linux-rdma@vger.kernel.org, eli@mellanox.com, target-devel@vger.kernel.org, linux-nfs@vger.kernel.org, bfields@fieldses.org From: Steve Wise Message-ID: <55B53FE6.1030509@opengridcomputing.com> Date: Sun, 26 Jul 2015 15:15:34 -0500 MIME-Version: 1.0 In-Reply-To: <55B51B7A.8030008@dev.mellanox.co.il> Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-nfs-owner@vger.kernel.org List-ID: On 7/26/2015 12:40 PM, Sagi Grimberg wrote: > >>> Ideally, the post contains a chain of all 4 registrations and the >>> rdma_read (and an opportunistic good scsi response). >> >> Just to be clear: This example is for IB only, correct? IW would >> require rkeys with REMOTE_WRITE and 4 read wrs. > > My assumption is that it would depend on max_sge_rd. > yea. > IB only? iWARP by definition isn't capable of doing rdma_read to > more than one scatter? Anyway, we'll need to calculate the number > of RDMA_READs. > The wire protocol limits the destination to a single stg/to/len (aka rkey/addr/len). Devices/fw/sw could implement some magic to support a single stg/to/len that maps to a scatter gather list of stags/tos/lens. >> And you're ignoring invalidation wrs (or read-with-inv) in the >> example... > > Yes, didn't want to inflate the example too much...