We make decisions on how to pick a poll group for a new
qpair by looking at each poll group's current_io_qpairs
count. But this count isn't always accurate since it
doesn't get updated until after the CONNECT has
been received.
This means that if we accept a bunch of connections
all at once, they may all get assigned the same poll
group, because the target poll groups counter doesn't
get immediately incremented.
So add a new counter, current_unassociated_qpairs,
to account for these qpairs. We protect this counter
with a lock, since the accept thread will increment
the counter, and the poll group thread will
decrement it when the qpair receives the CONNECT
allowing us to associated with a subsystem/controller..
If the qpair gets destroyed before the CONNECT is
received, we can use the qpair->connect_received
flag to decrement current_unassociated_qpairs.
Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I8bba8da2abfe225b3b9f981cd71b6f49e2b87391
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15693
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@nvidia.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Konrad Sztyber <konrad.sztyber@intel.com>