From: Chuck Lever <chuck.lever@oracle.com>
To: anna.schumaker@netapp.com
Cc: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org
Subject: [PATCH v2 21/21] xprtrdma: Optimize rpcrdma_post_recvs()
Date: Mon, 19 Aug 2019 18:51:49 -0400 [thread overview]
Message-ID: <156625508978.8161.1876379934869374429.stgit@seurat29.1015granger.net> (raw)
In-Reply-To: <156625401091.8161.14744201497689200191.stgit@seurat29.1015granger.net>
Micro-optimization: In rpcrdma_post_recvs, since commit e340c2d6ef2a
("xprtrdma: Reduce the doorbell rate (Receive)"), the common case is
to return without doing anything. Found with perf.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
net/sunrpc/xprtrdma/verbs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index db90083ed35b..ac2abf4578b9 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1465,7 +1465,7 @@ rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
count = 0;
needed = buf->rb_credits + (buf->rb_bc_srv_max_requests << 1);
- if (ep->rep_receive_count > needed)
+ if (likely(ep->rep_receive_count > needed))
goto out;
needed -= ep->rep_receive_count;
if (!temp)
next prev parent reply other threads:[~2019-08-19 22:52 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-19 22:35 [PATCH v2 00/21] NFS/RDMA client-side for-5.4 Chuck Lever
2019-08-19 22:36 ` [PATCH v2 01/21] SUNRPC: Remove rpc_wake_up_queued_task_on_wq() Chuck Lever
2019-08-19 22:37 ` [PATCH v2 02/21] SUNRPC: Inline xdr_commit_encode Chuck Lever
2019-08-19 22:37 ` [PATCH v2 03/21] xprtrdma: Refresh the documenting comment in frwr_ops.c Chuck Lever
2019-08-19 22:38 ` [PATCH v2 04/21] xprtrdma: Update obsolete comment Chuck Lever
2019-08-19 22:39 ` [PATCH v2 05/21] xprtrdma: Fix calculation of ri_max_segs again Chuck Lever
2019-08-19 22:40 ` [PATCH v2 06/21] xprtrdma: Boost maximum transport header size Chuck Lever
2019-08-19 22:40 ` [PATCH v2 07/21] xprtrdma: Boost client's max slot table size to match Linux server Chuck Lever
2019-08-19 22:41 ` [PATCH v2 08/21] xprtrdma: Rename CQE field in Receive trace points Chuck Lever
2019-08-19 22:42 ` [PATCH v2 09/21] xprtrdma: Rename rpcrdma_buffer::rb_all Chuck Lever
2019-08-19 22:43 ` [PATCH v2 10/21] xprtrdma: Toggle XPRT_CONGESTED in xprtrdma's slot methods Chuck Lever
2019-08-19 22:44 ` [PATCH v2 11/21] xprtrdma: Simplify rpcrdma_mr_pop Chuck Lever
2019-08-19 22:44 ` [PATCH v2 12/21] xprtrdma: Combine rpcrdma_mr_put and rpcrdma_mr_unmap_and_put Chuck Lever
2019-08-19 22:45 ` [PATCH v2 13/21] xprtrdma: Move rpcrdma_mr_get out of frwr_map Chuck Lever
2019-08-19 22:46 ` [PATCH v2 14/21] xprtrdma: Ensure creating an MR does not trigger FS writeback Chuck Lever
2019-08-19 22:47 ` [PATCH v2 15/21] xprtrdma: Cache free MRs in each rpcrdma_req Chuck Lever
2019-08-19 22:47 ` [PATCH v2 16/21] xprtrdma: Remove rpcrdma_buffer::rb_mrlock Chuck Lever
2019-08-19 22:48 ` [PATCH v2 17/21] xprtrdma: Use an llist to manage free rpcrdma_reps Chuck Lever
2019-08-19 22:49 ` [PATCH v2 18/21] xprtrdma: Clean up xprt_rdma_set_connect_timeout() Chuck Lever
2019-08-19 22:50 ` [PATCH v2 19/21] xprtrdma: Fix bc_max_slots return value Chuck Lever
2019-08-19 22:51 ` [PATCH v2 20/21] xprtrdma: Inline XDR chunk encoder functions Chuck Lever
2019-08-19 22:51 ` Chuck Lever [this message]
2019-08-22 20:18 ` [PATCH v2 00/21] NFS/RDMA client-side for-5.4 Schumaker, Anna
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