Re: [PATCH] debugobjects: Don't call fill_pool() in early boot non-task context of RT kernel

[Waiman Long <longman@redhat.com>]

On 5/20/26 2:04 PM, Thomas Gleixner wrote:
> On Wed, May 20 2026 at 12:57, Waiman Long wrote:
>> On 5/20/26 12:43 PM, Waiman Long wrote:
>>> It shouldn't really be a problem as fill_poll() will not called from
>>> non-preemptible context after early boot, but the lockdep warning can
>>> still cause confusion and anxiety. Fix that by further restricting the
>>> call to only in_task() context during early boot.
>> Sorry, the above paragraph isn't right. Will send out a v2.
> And please trim the back trace while at it.
OK, will send a v3.
>
>>> Fixes: 06e0ae988f6e ("debugobjects: Allow to refill the pool before SYSTEM_SCHEDULING")
>>> Signed-off-by: Waiman Long <longman@redhat.com>
>>> ---
>>>    lib/debugobjects.c | 7 +++++--
>>>    1 file changed, 5 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/lib/debugobjects.c b/lib/debugobjects.c
>>> index 12e2e42e6a31..236ea5e716df 100644
>>> --- a/lib/debugobjects.c
>>> +++ b/lib/debugobjects.c
>>> @@ -727,11 +727,14 @@ static void debug_objects_fill_pool(void)
>>>    
>>>    	/*
>>>    	 * On RT enabled kernels the pool refill must happen in preemptible
>>> -	 * context -- for !RT kernels we rely on the fact that spinlock_t and
>>> +	 * context or in task context during early boot.
>>> +	 *
>>> +	 * For !RT kernels we rely on the fact that spinlock_t and
>>>    	 * raw_spinlock_t are basically the same type and this lock-type
>>>    	 * inversion works just fine.
>>>    	 */
>>> -	if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible() || system_state < SYSTEM_SCHEDULING) {
>>> +	if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible() ||
>>> +	   (system_state < SYSTEM_SCHEDULING && in_task())) {
> Conflicts with:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/log/?h=core/urgent
>
Will rebase it to tip.

Thanks,
Longman