msg/async/rdma: event polling thread can block on event

[yuyuyu101]

No description provided.

[yuyuyu101]

@Adirl give a look

[Adirl]

•  if ((ceph_clock_now(cct) - last_inactive).to_nsec() / 1000 > cct->_conf->ms_async_rdma_polling_us) {
  

maybe should be with *:

•  if ((ceph_clock_now(cct) - last_inactive).to_nsec() * 1000 > cct->_conf->ms_async_rdma_polling_us) {
  

[yuyuyu101]

@Adirl not follow.. to_nsec() is nanoseconds(ns). we need to divide 1000 to become microseconds(us)

[Adirl]

@yuyuyu101
correct, i checked again, my bad :)

[Adirl]

@yuyuyu101
patch looks important and good to me,

consider this corner case:
since you do "continue" after "rearm=true" it could be that when returning to poll_cq() now gets many cqe's and therefore won't never go again into if(!n). meaning blocking on poll() we never happen. is that allowed?
hope i explained it well, let me know for any question

[yuyuyu101]

@Adirl why? if set rearm to true and got many cqe, after processing cqe we still can call poll. why it never happen?

[Adirl]

If they stop arriving so yes, you can get to poll