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authorChuck Lever <chuck.lever@oracle.com>2020-07-08 16:09:53 -0400
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2020-09-21 10:21:09 -0400
commit6f9f17287e78e5049931af2037b15b26d134a32a (patch)
tree61834c2cd426dc876c1cb267a2d09a0a431194d5 /net/sunrpc/xprt.c
parentdb0a86c4266ac36769f54e2ce33fff0300c9bc00 (diff)
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SUNRPC: Mitigate cond_resched() in xprt_transmit()
The original purpose of this expensive call is to prevent a long queue of requests from blocking other work. The cond_resched() call is unnecessary after just a single send operation. For longer queues, instead of invoking the kernel scheduler, simply release the transport send lock and return to the RPC scheduler. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc/xprt.c')
-rw-r--r--net/sunrpc/xprt.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index ceb190d1754d..f6c17e75f20e 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -1513,10 +1513,13 @@ xprt_transmit(struct rpc_task *task)
{
struct rpc_rqst *next, *req = task->tk_rqstp;
struct rpc_xprt *xprt = req->rq_xprt;
- int status;
+ int counter, status;
spin_lock(&xprt->queue_lock);
+ counter = 0;
while (!list_empty(&xprt->xmit_queue)) {
+ if (++counter == 20)
+ break;
next = list_first_entry(&xprt->xmit_queue,
struct rpc_rqst, rq_xmit);
xprt_pin_rqst(next);
@@ -1524,7 +1527,6 @@ xprt_transmit(struct rpc_task *task)
status = xprt_request_transmit(next, task);
if (status == -EBADMSG && next != req)
status = 0;
- cond_resched();
spin_lock(&xprt->queue_lock);
xprt_unpin_rqst(next);
if (status == 0) {