Messages in this thread | | | Subject | Re: [RFC 0/8] Copy Offload with Peer-to-Peer PCI Memory | From | Benjamin Herrenschmidt <> | Date | Wed, 19 Apr 2017 11:23:04 +1000 |
| |
On Tue, 2017-04-18 at 16:24 -0600, Jason Gunthorpe wrote: > Basically, all this list processing is a huge overhead compared to > just putting a helper call in the existing sg iteration loop of the > actual op. Particularly if the actual op is a no-op like no-mmu x86 > would use.
Yes, I'm leaning toward that approach too.
The helper itself could hang off the devmap though.
> Since dma mapping is a performance path we must be careful not to > create intrinsic inefficiencies with otherwise nice layering :) > > Jason
| |