From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sagi Grimberg Subject: Re: [PATCH RFC 2/9] IB/core: Introduce Signature Verbs API Date: Wed, 23 Oct 2013 13:42:12 +0300 Message-ID: <5267A804.6060804@mellanox.com> References: <1381851510-17290-1-git-send-email-sagig@mellanox.com> <1381851510-17290-3-git-send-email-sagig@mellanox.com> <1828884A29C6694DAF28B7E6B8A8237388CE2BFF@ORSMSX109.amr.corp.intel.com> <5263D2DE.8010500@mellanox.com> <1828884A29C6694DAF28B7E6B8A8237388CEA91E@ORSMSX109.amr.corp.intel.com> <52655282.1000505@mellanox.com> <1828884A29C6694DAF28B7E6B8A8237388CEE1C7@ORSMSX109.amr.corp.intel.com> <5266BA11.6090300@mellanox.com> <1828884A29C6694DAF28B7E6B8A8237388CEE286@ORSMSX109.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1828884A29C6694DAF28B7E6B8A8237388CEE286-P5GAC/sN6hkd3b2yrw5b5LfspsVTdybXVpNB7YpNyf8@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Hefty, Sean" Cc: "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Oren Duer , tzahio-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org List-Id: linux-rdma@vger.kernel.org On 10/22/2013 9:20 PM, Hefty, Sean wrote: >>> Would we lose anything making this a new operation for the QP, versus >> trying to hook it into the existing ib_post_send call? >> >> If I understand correctly you are suggesting making it a verb? Well this >> operation is a fast-path operation - so I guess we will loose it in this >> case. >> Take SCSI for example, for each IO operation submitted by SCSI >> mid-layer, transport layer should perform any protection policy that >> SCSI asked for. >> From this point of view, signature operation resembles fast >> registration (since the transport does not own the IOP data buffers, so >> it uses fast registration methods). >> That is why we are hooking into ib_post_send. > I'm suggesting multiple calls that can post to the send queue, rather than one call that does a giant switch statement at the beginning based on the opcode. Although I understand where you are coming from, We also lose in this case. If we go down this rode, we block the user from saving a HW doorbell by concatenating signature and RDMA WRs to a post list. I assume this is why fast_reg is also an extension of ib_post_send. > -- > 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 -- 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