From bade4be69a6ea6f38c5894468ede10ee60b6f7a0 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 11 Mar 2021 13:25:01 -0500 Subject: svcrdma: Revert "svcrdma: Reduce Receive doorbell rate" I tested commit 43042b90cae1 ("svcrdma: Reduce Receive doorbell rate") with mlx4 (IB) and software iWARP and didn't find any issues. However, I recently got my hardware iWARP setup back on line (FastLinQ) and it's crashing hard on this commit (confirmed via bisect). The failure mode is complex. - After a connection is established, the first Receive completes normally. - But the second and third Receives have garbage in their Receive buffers. The server responds with ERR_VERS as a result. - When the client tears down the connection to retry, a couple of posted Receives flush twice, and that corrupts the recv_ctxt free list. - __svc_rdma_free then faults or loops infinitely while destroying the xprt's recv_ctxts. Since 43042b90cae1 ("svcrdma: Reduce Receive doorbell rate") does not fix a bug but is a scalability enhancement, it's safe and appropriate to revert it while working on a replacement. Fixes: 43042b90cae1 ("svcrdma: Reduce Receive doorbell rate") Signed-off-by: Chuck Lever --- include/linux/sunrpc/svc_rdma.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h index 7c693b31965e..1e76ed688044 100644 --- a/include/linux/sunrpc/svc_rdma.h +++ b/include/linux/sunrpc/svc_rdma.h @@ -104,7 +104,6 @@ struct svcxprt_rdma { wait_queue_head_t sc_send_wait; /* SQ exhaustion waitlist */ unsigned long sc_flags; - u32 sc_pending_recvs; struct list_head sc_read_complete_q; struct work_struct sc_work; -- cgit v1.2.3