From 6dc6ec9e04c468d994bff6eb660f3146f94cbfd9 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Mon, 19 Aug 2019 18:47:10 -0400 Subject: xprtrdma: Cache free MRs in each rpcrdma_req Instead of a globally-contended MR free list, cache MRs in each rpcrdma_req as they are released. This means acquiring and releasing an MR will be lock-free in the common case, even outside the transport send lock. The original idea of per-rpcrdma_req MR free lists was suggested by Shirley Ma several years ago. I just now figured out how to make that idea work with on-demand MR allocation. Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/frwr_ops.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'net/sunrpc/xprtrdma/frwr_ops.c') diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c index 1f2e3dda7401..0e740bae2d80 100644 --- a/net/sunrpc/xprtrdma/frwr_ops.c +++ b/net/sunrpc/xprtrdma/frwr_ops.c @@ -488,8 +488,8 @@ static void frwr_wc_localinv_wake(struct ib_cq *cq, struct ib_wc *wc) /* WARNING: Only wr_cqe and status are reliable at this point */ trace_xprtrdma_wc_li_wake(wc, frwr); - complete(&frwr->fr_linv_done); __frwr_release_mr(wc, mr); + complete(&frwr->fr_linv_done); } /** @@ -587,11 +587,15 @@ static void frwr_wc_localinv_done(struct ib_cq *cq, struct ib_wc *wc) struct rpcrdma_frwr *frwr = container_of(cqe, struct rpcrdma_frwr, fr_cqe); struct rpcrdma_mr *mr = container_of(frwr, struct rpcrdma_mr, frwr); + struct rpcrdma_rep *rep = mr->mr_req->rl_reply; /* WARNING: Only wr_cqe and status are reliable at this point */ trace_xprtrdma_wc_li_done(wc, frwr); - rpcrdma_complete_rqst(frwr->fr_req->rl_reply); __frwr_release_mr(wc, mr); + + /* Ensure @rep is generated before __frwr_release_mr */ + smp_rmb(); + rpcrdma_complete_rqst(rep); } /** @@ -624,7 +628,6 @@ void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req) frwr = &mr->frwr; frwr->fr_cqe.done = frwr_wc_localinv; - frwr->fr_req = req; last = &frwr->fr_invwr; last->next = NULL; last->wr_cqe = &frwr->fr_cqe; -- cgit v1.2.3