On Tue, Jul 14, 2015 at 03:54:15PM -0500, Steve Wise wrote: > > > 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. Read the exchange again? You asked this: > > > could have old drivers that don't currently have support for > > > local_dma_lkey allocate their own private pd/dma_mr (via their The answer to why that doesn't work is: In the generic case of old drivers every PD has a different local_dma_lkey value. 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
