> -----Original Message----- > From: linux-nfs-owner@xxxxxxxxxxxxxxx [mailto:linux-nfs-owner@xxxxxxxxxxxxxxx] On Behalf Of Jason Gunthorpe > Sent: Tuesday, July 14, 2015 3:45 PM > To: Steve Wise > Cc: 'Christoph Hellwig'; 'Sagi Grimberg'; 'Tom Talpey'; 'Doug Ledford'; sagig@xxxxxxxxxxxx; ogerlitz@xxxxxxxxxxxx; > roid@xxxxxxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx; eli@xxxxxxxxxxxx; target-devel@xxxxxxxxxxxxxxx; linux-nfs@xxxxxxxxxxxxxxx; > trond.myklebust@xxxxxxxxxxxxxxx; bfields@xxxxxxxxxxxx; 'Oren Duer' > Subject: Re: [PATCH V3 1/5] RDMA/core: Transport-independent access flags > > On Tue, Jul 14, 2015 at 03:40:49PM -0500, Steve Wise wrote: > > > local_dma_lkey appears to be global, it works with any PD. > > > > > > ib_get_dma_mr is tied to a PD, so it cannot replace local_dma_lkey at > > > the struct device level. > > > > > > ib_alloc_pd is the in-kernel entry point, the UAPI calls > > > device->alloc_pd directly.. So how about the below patch as a starting > > > >point? > > > > > > (Steve the goal of step #1 would be to remove ib_get_dma_mr from ULPs > > > Follow on patches would be to convert all ULPs to use this API change.) > > > I'm not seeing the benefit of adding pd->local_dma_lkey? > > pd->device->local_dma_lkey is there for core and ULP use, and we > > could have old drivers that don't currently have support for > > local_dma_lkey allocate their own private pd/dma_mr (via their > > private functions for doing this) with only LOCAL_WRITE access > > flags, and export that lkey as the device->local_dma_lkey. Wouldn't > > that be simpler? > > It would be, but AFAIK that can't work? > > My understanding is if you create a QP against a PD then only lkeys > and rkeys (and local_dma_rkey) created against that PD are valid for > use with that QP. > > I can't use an lkey from a PD not associated with the QP. > > Am I wrong on this? Kernel users can use the local_dma_lkey for all lkey IO on all QPs (ignoring the iwarp read issue). Look at sc_dma_lkey in the NFSRDMA server. > > Jason > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > 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@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
