Commits
Michael J. Ruhl committed 90b2620e6a8
IB/hfi1: Fix a latency issue for small messages
A recent performance enhancement introduced a latency issue in the
HFI message path. The new algorithm removed a forced call send for
PIO messages and added a forced schedule event for messages larger
than the MTU.
For PIO, the schedule path can introduce thrashing that can
significantly impact the throughput for small messages.
If a message size is within the PIO threshold, always take the send
path.
Fixes: 0b79b27748cb ("IB/{hfi1, qib, rdmavt}: Schedule multi RC/UC packets instead of posting")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>