> -----Original Message----- > From: Sagi Grimberg [mailto:sagig@xxxxxxxxxxxxxxxxxx] > Sent: Tuesday, July 14, 2015 3:39 AM > To: Jason Gunthorpe > Cc: linux-rdma@xxxxxxxxxxxxxxx; Christoph Hellwig; Steve Wise; Or Gerlitz; Oren Duer; Chuck Lever; Bart Van Assche; Liran Liss; Hefty, > Sean; Doug Ledford; Tom Talpey > Subject: Re: Kernel fast memory registration API proposal [RFC] > > On 7/13/2015 7:30 PM, Jason Gunthorpe wrote: > > On Fri, Jul 10, 2015 at 12:09:37PM +0300, Sagi Grimberg wrote: > >> Given the last discussions on our in-kernel memory registration API I > >> thought I'd propose another approach to address this. > > > > I assume you can put your new indirect registrations under this API > > without changing the callers? > > Correct, it's a bonus. The main idea here is to simplify the API for > ULPs. > > > > >> /* > >> * Set the SG list in the MR, fail if the sg > >> * list is not well aligned (caller should handle > >> * it) or mr does not have enough room to fit the sg. > >> */ > >> rc = ib_mr_set_sg(mr, sg, sg_nents); > >> if (rc) > >> /* HW does not support - Need to handle it */ > > > > I think this call should also do the post. > > > > There seems to be nothing the ULP can customize about the post step > > that needs to be exposed.. and bundling the post allows more > > flexability to implement different schemes without impacting the ULPs. > > This is exactly what I don't want to do. I don't think that implicit > posting is a good idea for reasons that I mentioned earlier: > > "This is where I have a problem. Providing an API that may or may not > post a work request on my QP is confusing, and I don't understand its > semantics at all. Do I need to reserve slots on my QP? should I ask for > a completion? If we suppress the completion will I see an error > completion? What should I expect to find in the wr_id?" > > We're much better off with keeping the post interface in place but > have it much simpler. > > Sagi. I agree...I don't like the idea of WR posting done under the covers. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
