On Wed, Nov 16, 2022 at 7:16 PM Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx> wrote: > > In a networking test on ChromeOS, we find that using the new CONFIG_RCU_LAZY > causes a networking test to fail in the teardown phase. > > The failure happens during: ip netns del <name> And ? What happens then next ? > > Using ftrace, I found the callbacks it was queuing which this series fixes. Use > call_rcu_flush() to revert to the old behavior. With that, the test passes. What is this test about ? What barrier was used to make it not flaky ? Was it depending on some undocumented RCU behavior ? Maybe adding a sysctl to force the flush would be better for functional tests ? I would rather change the test(s), than adding call_rcu_flush(), adding merge conflicts to future backports.
