net/bind_wildcard flakiness

Hi!

The bind_wildcard used to be rock solid, no flakes in last 1000 runs, but then around the time Eric posted his Rx optimizations we hit one flake, and now we hit another:

List:
https://netdev.bots.linux.dev/contest.html?test=bind-wildcard&executor=vmksft-net&pass=0

Outputs:
https://netdev-3.bots.linux.dev/vmksft-net/results/122022/14-bind-wildcard/stdout
https://netdev-3.bots.linux.dev/vmksft-net/results/123463/14-bind-wildcard/stdout

One does:

# 0.21 [+0.00] # bind_wildcard.c:768:reuseaddr:Expected ret (-1) == 0 (0) # 0.21 [+0.00] # reuseaddr: Test terminated by assertion
# 0.21 [+0.00] # FAIL bind_wildcard.v6_any_only_v6_v4mapped_any.reuseaddr

The other:

# 0.25 [+0.00] # bind_wildcard.c:775:plain:Expected ret (-1) == 0 (0) # 0.25 [+0.00] # plain: Test terminated by assertion
# 0.25 [+0.00] # FAIL bind_wildcard.v6_local_v6_v4mapped_any.plain

The only change on the infra side is that I increased disk IO cap, so the builds are now faster.

From: Jakub Kicinski <[email protected]>
Date: Fri, 16 May 2025 10:05:42 -0700

Thanks for the report.

The test only calls bind() so I guess it's not related to the RX optimisation series.

This is weird because both cases failed when bind() should succeed.

Will try to reproduce on my end.