Re: [PATCH net 8/9] selftests: drv-net: pp_alloc_fail: lower traffic expectations

On Fri, Oct 03, 2025 at 04:30:24PM -0700, Jakub Kicinski wrote:

...

@@ -91,9 +92,14 @@ from lib.py import cmd, tool, GenerateTraffic if s2['rx-alloc-fail'] - s1['rx-alloc-fail'] < 1: raise KsftSkipEx("Allocation failures not increasing")

•    if s2['rx-alloc-fail'] - s1['rx-alloc-fail'] < 100:
  

•        raise KsftSkipEx("Allocation increasing too slowly", s2['rx-alloc-fail'] - s1['rx-alloc-fail'],
  

•                         "packets:", s2['rx-packets'] - s1['rx-packets'])
  

•    pkts = s2['rx-packets'] - s1['rx-packets']
  

•    # Expecting one failure per 512 buffers, 3.1x safety margin
  

•    want_fails = math.floor(pkts / 512 / 3.1)
  

•    seen_fails = s2['rx-alloc-fail'] - s1['rx-alloc-fail']
  

•    if s2['rx-alloc-fail'] - s1['rx-alloc-fail'] < want_fails:
  

I guess this could be as follows. (Completely untested!)

if seen_fails < want_fails:

•        raise KsftSkipEx("Allocation increasing too slowly", seen_fails,
  

•                         "packets:", pkts)
  

•    ksft_pr(f"Seen: pkts:{pkts} fails:{seen_fails} (pass thrs:{want_fails})")
  

# Basic failures are fine, try to wobble some settings to catch extra failures check_traffic_flowing()

The nit above withstanding, this looks good to me.

Reviewed-by: Simon Horman horms@kernel.org