On Wed, Oct 26, 2022 at 7:49 AM Sebastian Andrzej Siewior
<bigeasy@xxxxxxxxxxxxx> wrote:
>
> lru_gen_add_mm() has been added within an IRQ-off region in the commit
> mentioned below. The other invocations of lru_gen_add_mm() are not within
> an IRQ-off region.
> The invocation within IRQ-off region is problematic on PREEMPT_RT
> because the function is using a spin_lock_t which must not be used
> within IRQ-disabled regions.
>
> The other invocations of lru_gen_add_mm() occur while task_struct::alloc_lock
> is acquired.
> Move lru_gen_add_mm() after interrupts are enabled and before
> task_unlock().
>
> Fixes: bd74fdaea1460 ("mm: multi-gen LRU: support page table walks")
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Thanks.
Acked-by: Yu Zhao <yuzhao@xxxxxxxxxx>
