[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <a48ec24f-fe53-4a62-9397-e42a23fc3a2d@amd.com>
Date: Wed, 9 Oct 2024 07:54:15 +0530
From: Neeraj Upadhyay <Neeraj.Upadhyay@....com>
To: Frederic Weisbecker <frederic@...nel.org>,
LKML <linux-kernel@...r.kernel.org>
Cc: Boqun Feng <boqun.feng@...il.com>, Joel Fernandes
<joel@...lfernandes.org>, "Paul E . McKenney" <paulmck@...nel.org>,
Uladzislau Rezki <urezki@...il.com>, Zqiang <qiang.zhang1211@...il.com>,
rcu <rcu@...r.kernel.org>
Subject: Re: [PATCH 3/3] rcu: Report callbacks enqueued on offline CPU blind
spot
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 <paulmck@...nel.org>
>> Signed-off-by: Frederic Weisbecker <frederic@...nel.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
>>
>>
Powered by blists - more mailing lists