"Paul E. McKenney" <paulmck@xxxxxxxxxx> writes: > On Wed, Apr 14, 2021 at 10:59:23AM -0700, Alexei Starovoitov wrote: >> On Wed, Apr 14, 2021 at 10:52 AM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote: >> > >> > > > > > if (num_online_cpus() > 1) >> > > > > > synchronize_rcu(); >> > >> > In CONFIG_PREEMPT_NONE=y and CONFIG_PREEMPT_VOLUNTARY=y kernels, this >> > synchronize_rcu() will be a no-op anyway due to there only being the >> > one CPU. Or are these failures all happening in CONFIG_PREEMPT=y kernels, >> > and in tests where preemption could result in the observed failures? >> > >> > Could you please send your .config file, or at least the relevant portions >> > of it? >> >> That's my understanding as well. I assumed Toke has preempt=y. >> Otherwise the whole thing needs to be root caused properly. > > Given that there is only a single CPU, I am still confused about what > the tests are expecting the membarrier() system call to do for them. It's basically a proxy for waiting until the objects are freed on the kernel side, as far as I understand... -Toke
