On 10/2/2024 8:30 PM, Frederic Weisbecker wrote:
> Le Wed, Oct 02, 2024 at 04:57:38PM +0200, Frederic Weisbecker a écrit :
>> Callbacks enqueued after rcutree_report_cpu_dead() fall into RCU barrier
>> blind spot. Report any potential misuse.
>>
>> Reported-by: Paul E. McKenney <paul...@kernel.org>
>> Signed-off-by: Frederic Weisbecker <frede...@kernel.org>
>> ---
>> kernel/rcu/tree.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
>> index a60616e69b66..36070b6bf4a1 100644
>> --- a/kernel/rcu/tree.c
>> +++ b/kernel/rcu/tree.c
>> @@ -3084,8 +3084,11 @@ __call_rcu_common(struct rcu_head *head,
>> rcu_callback_t func, bool lazy_in)
>> head->func = func;
>> head->next = NULL;
>> kasan_record_aux_stack_noalloc(head);
>> +
>> local_irq_save(flags);
>> rdp = this_cpu_ptr(&rcu_data);
>> + RCU_LOCKDEP_WARN(rcu_rdp_cpu_online(rdp), "Callback enqueued on offline
>> CPU!");
>
> This should be !rcu_rdp_cpu_online(rdp)
>
With this patch series, 600 mins RCU torture overnight testing completed
without failures at my end.
- Neeraj
> Sigh...
>
>> +
>> lazy = lazy_in && !rcu_async_should_hurry();
>>
>> /* Add the callback to our list. */
>> --
>> 2.46.0
>>
>>
