svcrdma: Don't account for Receive queue "starvation"
authorChuck Lever <chuck.lever@oracle.com>
Fri, 23 Jun 2017 21:18:08 +0000 (17:18 -0400)
committerJ. Bruce Fields <bfields@redhat.com>
Wed, 28 Jun 2017 18:21:44 +0000 (14:21 -0400)
commit2d6491a56c76f2d6c22aaa710e2a4d04ad41529b
tree2ca744381b0491d7c908d1004658e7a8bf16971d
parentca5c76aba7502d52a6019358ec04bd4d734037d7
svcrdma: Don't account for Receive queue "starvation"

>From what I can tell, calling ->recvfrom when there is no work to do
is a normal part of operation. This is the only way svc_recv can
tell when there is no more data ready to receive on the transport.

Neither the TCP nor the UDP transport implementations have a
"starve" metric.

The cost of receive starvation accounting is bumping an atomic, which
results in extra (IMO unnecessary) bus traffic between CPU sockets,
while holding a spin lock.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
net/sunrpc/xprtrdma/svc_rdma_recvfrom.c