[PATCH] irqchip/gic-v3-its: Don't acquire rt_spin_lock in allocate_vpe_l1_table()

[Thomas Gleixner]

On Sun, Jan 11 2026 at 18:02, Waiman Long wrote:
> On 1/11/26 5:38 AM, Marc Zyngier wrote:
>>> Also that patch seems to be incomplete because there is another
>>> allocation further down in allocate_vpe_l1_table()....
>> Yeah, I wondered why page allocation wasn't affected by this issue,
>> but didn't try to find out.
>
> The use of GFP_ATOMIC flag in the page allocation request may help it to 
> dip into the reserved area and avoid taking any spinlock. In my own 
> test, just removing the kzalloc() call is enough to avoid any invalid 
> context warning. In the page allocation code, there is a zone lock and a 
> per_cpu_pages lock. They were not acquired in my particular test case, 
> though further investigation may be needed to make sure it is really safe.

They might be acquired though. Only alloc_pages_nolock() guarantees that
no lock is taken IIRC.