Add resize tests to rss_drv.py. Devices without dynamic table sizing
are skipped via _require_dynamic_indir_size().
resize_periodic: set a periodic 4-entry table, shrink channels to
fold, grow back to unfold. Check the exact pattern is preserved. Has
main and non-default context variants.
resize_below_user_size_reject: send a periodic table with user_size
between the big and small device table sizes. Verify that shrinking
below user_size is rejected even though the table is periodic. Has
main and non-default context variants.
resize_nonperiodic_reject: set a non-periodic table (equal N), verify
that channel reduction is rejected.
resize_nonperiodic_no_corruption: verify a failed resize leaves both
the indirection table contents and the channel count unchanged.
Signed-off-by: Björn Töpel <bjorn@kernel.org>
Link: https://patch.msgid.link/20260320085826.1957255-5-bjorn@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a test which checks that the RSS table is at least 4x the max
queue count supported by the device. The original RSS spec from
Microsoft stated that the RSS indirection table should be 2 to 8
times the CPU count, presumably assuming queue per CPU. If the
CPU count is not a power of two, however, a power-of-2 table
2x larger than queue count results in a 33% traffic imbalance.
Validate that the indirection table is at least 4x the queue
count. This lowers the imbalance to 16% which empirically
appears to be more acceptable to memcache-like workloads.
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260131225454.1225151-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
