On Mon, Sep 01, 2025 at 10:31:38AM -0700, Jakub Kicinski wrote: > The rss_ctx test has gotten pretty flaky after I increased > the queue count in NIPA 2->3. Not 100% clear why. We get > a lot of failures in the rss_ctx.test_hitless_key_update case. > > Looking closer it appears that the failures are mostly due > to startup costs. I measured the following timing for ethtool -X: > - python cmd(shell=True) : 150-250msec > - python cmd(shell=False) : 50- 70msec > - timed in bash : 45- 55msec > - YNL Netlink call : 2- 4msec > - .set_rxfh callback : 1- 2msec > > The target in the test was set to 200msec. We were mostly measuring > ethtool startup cost it seems. Switch to YNL since it's 100x faster. > > Lower the pass criteria to 150msec, no real science behind this number > but we removed some overhead, drivers which previously passed 200msec > should easily pass 150msec now. > > Separately we should probably follow up on defaulting to shell=False, > when script doesn't explicitly ask for True, because the overhead > is rather significant. > > Switch from _rss_key_rand() to random.randbytes(), YNL takes a binary > array rather than array of ints. > > Signed-off-by: Jakub Kicinski <[email protected]> > --- > v2: > - increase the threshold to safer 150msec > - mention change away from _rss_key_rand() > v1: https://lore.kernel.org/[email protected]
Reviewed-by: Simon Horman <[email protected]>
