> On Dec 27, 2018, at 20:21, Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > > Hi Trond- > > I've chased down a couple of remaining regressions with the v4.20 NFS client, > and they seem to be rooted in this commit. > > When using sec=krb5, krb5i, or krb5p I found that multi-threaded workloads > trigger a lot of server-side disconnects. This is with TCP and RDMA transports. > An instrumented server shows that the client is under-running the GSS sequence > number window. I monitored the order in which GSS sequence numbers appear on > the wire, and after this commit, the sequence numbers are wildly misordered. > If I revert the hunk in xprt_request_enqueue_transmit, the problem goes away. > > I also found that reverting that hunk results in a 3-4% improvement in fio > IOPS rates, as well as improvement in average and maximum latency as reported > by fio. > Hmm… Provided the sequence numbers still lie within the window, then why would the order matter? Cheers Trond _________________________________ Trond Myklebust Linux NFS client maintainer, Hammerspace trond.myklebust@xxxxxxxxxxxxxxx
