[PATCH 0/3] Avoid no-op transport enqueues

[Chuck Lever <cel@kernel.org>]

From: Chuck Lever <chuck.lever@oracle.com>

Reduce the amount of wasted work the svc thread scheduler has to do
when no work can be scheduled. Exiting threads already check for
work so no work is lost.

The three patches in this series each identify a particular scenario
where an enqueue becomes a no-op. I've also measured a slight uptick
in IOPS and data throughput as well as a drop in 50th percentile
latency for simple workloads on fast storage.

Chuck Lever (3):
  sunrpc: skip svc_xprt_enqueue when no work is pending
  sunrpc: skip svc_xprt_enqueue in svc_xprt_received when idle
  sunrpc: skip svc_xprt_enqueue when transport is busy

 net/sunrpc/svc_xprt.c | 46 +++++++++++++++++++++++++++++++++++++------
 1 file changed, 40 insertions(+), 6 deletions(-)

-- 
2.53.0