在 2018/12/7 1:39, Jason Gunthorpe 写道: > On Thu, Dec 06, 2018 at 04:23:09PM +0100, Christoph Hellwig wrote: >> On Thu, Dec 06, 2018 at 04:39:20PM +0800, oulijun wrote: >>> Hi, Christoph Hellwig & Jason >>> >>> I found a question about IB core recently. We need to call >>> get_dma_mr verbs and don't enable the mr_access_flags for >>> IB_ACCESS_REMOTE_ATOMIC. Why? Is it not supported? What should >>> we do if we need to call get_dma_mr for allowing incoming RDMA >>> Atomic in mr? >> You should never call get_dma_mr yourself. Currently we have no >> kernel ULPs that want to use atomic operations. But if you plan to >> submit one you can add a patch to the front of the series to enable >> atomic access in __ib_alloc_pd. However we really should only do >> that for local access - using the global rkey is a really bad idea >> an discouraged. > I think we already said we were not going to accept new ULPs that use > a remotely accessible global MR. > > So there is no reason to use IB_ACCESS_REMOTE_ATOMIC with > get_dma_mr(), you must create individual, and limited, MRs to get an > rkey. > > Jason > > Thanks. I see.
