Re: [PATCH v2] memcg: Remove the lockdep assert from __mod_objcg_mlstate().

[Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>]

On 2024-05-28 07:59:57 [-0700], Shakeel Butt wrote:
> One question on VM_WARN_ON_IRQS_ENABLED() in __mod_memcg_lruvec_state().
> On a PREEMPT_RT kernel with CONFIG_DEBUG_VM, will that
> VM_WARN_ON_IRQS_ENABLED() cause a splat or VM_WARN_ON_IRQS_ENABLED is
> special on PREEMPT_RT kernels?

we have the following in the header file:

| #ifdef CONFIG_DEBUG_VM_IRQSOFF
| #define VM_WARN_ON_IRQS_ENABLED() WARN_ON_ONCE(!irqs_disabled())
| #else
| #define VM_WARN_ON_IRQS_ENABLED() do { } while (0)
| #endif

and this in Kconfig:
| config DEBUG_VM_IRQSOFF
|         def_bool DEBUG_VM && !PREEMPT_RT
|

which means on PREEMPT_RT we end up with "do {…"

Sebastian