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
