[PATCH net-next v2 0/9] ibmvnic: Performance improvements and other updates

Thomas Falcon tlfalcon at linux.ibm.com
Thu Nov 19 12:12:16 AEDT 2020


The first three patches utilize a hypervisor call allowing multiple 
TX and RX buffer replenishment descriptors to be sent in one operation,
which significantly reduces hypervisor call overhead. The xmit_more
and Byte Queue Limit API's are leveraged to provide this support
for TX descriptors.

The subsequent two patches remove superfluous code and members in
TX completion handling function and TX buffer structure, respectively,
and remove unused routines.

Finally, four patches which ensure that device queue memory is
cache-line aligned, resolving slowdowns observed in PCI traces,
as well as optimize the driver's NAPI polling function and 
to RX buffer replenishment are provided by Dwip Banerjee.

This series provides significant performance improvements, allowing
the driver to fully utilize 100Gb NIC's.

v2 updates:

1) Removed three patches from the original series which
   were bug fixes and thus better suited for the net tree,
   suggested by Jakub Kicinski.
2) Fixed error handling when initializing device queues,
   suggested by Jakub Kicinski.
3) Fixed bug where queued entries were not flushed after a
   dropped frame, also suggested by Jakub. Two functions,
   ibmvnic_tx_scrq_flush and its helper ibmvnic_tx_scrq_clean_buffer,
   were introduced to ensure that queued frames are either submitted
   to firmware or, if that is not successful, freed as dropped and
   associated data structures are updated with the new device queue state.

Dwip N. Banerjee (4):
  ibmvnic: Ensure that device queue memory is cache-line aligned
  ibmvnic: Correctly re-enable interrupts in NAPI polling routine
  ibmvnic: Use netdev_alloc_skb instead of alloc_skb to replenish RX
    buffers
  ibmvnic: Do not replenish RX buffers after every polling loop

Thomas Falcon (5):
  ibmvnic: Introduce indirect subordinate Command Response Queue buffer
  ibmvnic: Introduce batched RX buffer descriptor transmission
  ibmvnic: Introduce xmit_more support using batched subCRQ hcalls
  ibmvnic: Clean up TX code and TX buffer data structure
  ibmvnic: Remove send_subcrq function

 drivers/net/ethernet/ibm/ibmvnic.c | 398 ++++++++++++++++++-----------
 drivers/net/ethernet/ibm/ibmvnic.h |  27 +-
 2 files changed, 256 insertions(+), 169 deletions(-)

-- 
2.26.2



More information about the Linuxppc-dev mailing list