From mboxrd@z Thu Jan 1 00:00:00 1970 From: 'Christoph Hellwig' Subject: Re: [PATCH V3 1/5] RDMA/core: Transport-independent access flags Date: Thu, 9 Jul 2015 01:00:42 -0700 Message-ID: <20150709080042.GA27629@infradead.org> References: <20150707090001.GB11736@infradead.org> <559B9891.8060907@dev.mellanox.co.il> <000b01d0b8bd$f2bfcc10$d83f6430$@opengridcomputing.com> <20150707161751.GA623@obsidianresearch.com> <559BFE03.4020709@dev.mellanox.co.il> <20150707213628.GA5661@obsidianresearch.com> <559CD174.4040901@dev.mellanox.co.il> <20150708190842.GB11740@obsidianresearch.com> <20150708203205.GA21847@infradead.org> <20150709000337.GE16812@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150709000337.GE16812-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jason Gunthorpe Cc: 'Christoph Hellwig' , Sagi Grimberg , Steve Wise , dledford-H+wXaHxf7aLQT0dZR+AlfA@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, trond.myklebust-7I+n7zu2hftEKMMhf/gKZA@public.gmane.org, bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org, Oren Duer List-Id: linux-rdma@vger.kernel.org On Wed, Jul 08, 2015 at 06:03:37PM -0600, Jason Gunthorpe wrote: > The major trouble with that is that the new MR types work by posting > work to the send queue, that work creates the MR. > > I don't know all the details of how those schemes work, but it doesn't > look like it fits into this model ? It sorta does, but we do need a QP argument. I have implemented this abstraction in a driver, but it's still usign driver specific data structures at this point, so extracting all the arguments is a bit of a mess. But if there is some interest I can try to polish it up and port an existing driver or two to it. Note that post_send isn't really used for alloating the MR structure but performing the registration. > Maybe if rdma_register_sg was the only API and it accepted a QP, under > the hood it could re-use a pooled/create a non-queued (F)MR, or issue > FRMR, or work with indirect? I really want to avoid another allocator in my driver. With the blk-mq model we basically preallocate a request with all resoruces, so right now I totally avoid allocations in I/O path, which is something I'd like to keep if possible. -- 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