From d9b13c203003cfb78c1f216049a204d385ccaeff Mon Sep 17 00:00:00 2001 From: Jianxin Xiong Date: Mon, 25 Jul 2016 13:39:45 -0700 Subject: IB/rdmavt, hfi1: Fix NFSoRDMA failure with FRMR enabled Hanging has been observed while writing a file over NFSoRDMA. Dmesg on the server contains messages like these: [ 931.992501] svcrdma: Error -22 posting RDMA_READ [ 952.076879] svcrdma: Error -22 posting RDMA_READ [ 982.154127] svcrdma: Error -22 posting RDMA_READ [ 1012.235884] svcrdma: Error -22 posting RDMA_READ [ 1042.319194] svcrdma: Error -22 posting RDMA_READ Here is why: With the base memory management extension enabled, FRMR is used instead of FMR. The xprtrdma server issues each RDMA read request as the following bundle: (1)IB_WR_REG_MR, signaled; (2)IB_WR_RDMA_READ, signaled; (3)IB_WR_LOCAL_INV, signaled & fencing. These requests are signaled. In order to generate completion, the fast register work request is processed by the hfi1 send engine after being posted to the work queue, and the corresponding lkey is not valid until the request is processed. However, the rdmavt driver validates lkey when the RDMA read request is posted and thus it fails immediately with error -EINVAL (-22). This patch changes the work flow of local operations (fast register and local invalidate) so that fast register work requests are always processed immediately to ensure that the corresponding lkey is valid when subsequent work requests are posted. Local invalidate requests are processed immediately if fencing is not required and no previous local invalidate request is pending. To allow completion generation for signaled local operations that have been processed before posting to the work queue, an internal send flag RVT_SEND_COMPLETION_ONLY is added. The hfi1 send engine checks this flag and only generates completion for such requests. Reviewed-by: Mike Marciniszyn Signed-off-by: Jianxin Xiong Signed-off-by: Dennis Dalessandro Signed-off-by: Doug Ledford --- include/rdma/rdmavt_qp.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/rdma') diff --git a/include/rdma/rdmavt_qp.h b/include/rdma/rdmavt_qp.h index 56adcfcabe0b..13902dd319a9 100644 --- a/include/rdma/rdmavt_qp.h +++ b/include/rdma/rdmavt_qp.h @@ -148,6 +148,7 @@ * Internal send flags */ #define RVT_SEND_RESERVE_USED IB_SEND_RESERVED_START +#define RVT_SEND_COMPLETION_ONLY (IB_SEND_RESERVED_START << 1) /* * Send work request queue entry. -- cgit v1.2.3