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

[Sebastian Andrzej Siewior]

On 2026-01-13 15:25:26 [-0800], Alexei Starovoitov wrote:
> On Tue, Jan 13, 2026 at 3:55 AM Sebastian Andrzej Siewior
> <bigeasy@xxxxxxxxxxxxx> wrote:
> > The last one does local_lock_irqsave() on PREEMPT_RT which does a
> > spin_lock(). That means atomic context is not possible. Where did I make
> > a wrong turn? Or did this change recently? I do remember that Alexei
> > reworked parts of the allocator to make the local_lock based trylock
> > allocation work.
> 
> Are you forgetting about local_lock_is_locked() in __slab_alloc() ?

Yeah but this just checks it. Further down the road there is
local_lock_cpu_slab() for the allocation and there is no try-lock on RT.

> With sheaves the whole thing will be very different.
Yes.

Sebastian