From mboxrd@z Thu Jan 1 00:00:00 1970 From: Haggai Eran Subject: Re: [PATCH 36/41] IB/hfi1: add low level page locking Date: Thu, 9 Jul 2015 10:33:16 +0300 Message-ID: <559E23BC.1040500@mellanox.com> References: <20150611230710.16479.62955.stgit@phlsvslse11.ph.intel.com> <20150611231142.16479.41039.stgit@phlsvslse11.ph.intel.com> <32E1700B9017364D9B60AED9960492BC2575DAA8@fmsmsx120.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <32E1700B9017364D9B60AED9960492BC2575DAA8-RjuIdWtd+YbTXloPLtfHfbfspsVTdybXVpNB7YpNyf8@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Marciniszyn, Mike" , Or Gerlitz Cc: Doug Ledford , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-rdma@vger.kernel.org On 09/07/2015 01:08, Marciniszyn, Mike wrote: >> anything wrong with the umem services provided by the IB core that >> requires this implementation? what? >> > > The current level of the API is mismatched with the PSM SDMA. > > The ib_umem api: > - maps an SG list which isn't required by PSM since DMA mapping is done by the low level SDMA Can I ask why do you prefer mapping page by page over using a single sg list? > - the mapping is bi-directional vs. from device > - The pd's context is not there > > Certainly we would consider a core change that provides just the page locking and we could fake a context. > > Mike -- 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