Re: [PATCH 0/3] x86/mm: DEBUG_PAGEALLOC musings

On 8/4/26 13:01, Peter Zijlstra wrote:
> On Tue, Aug 04, 2026 at 11:34:36AM -0700, Dave Hansen wrote:
>> On 7/29/26 04:08, Peter Zijlstra wrote:
>>> my take on how we should be 'fixing' this DEBUG_PAGEALLOC thing. It appears to
>>> boot in qemu with debug_pagealloc=on and such things.
>> The approach looks fine to me. The only thing we might want to do is add
>> a warning of some kind in the split/join paths for CPA_DEBUG_PAGEALLOC.
> So if you have lockdep enabled hitting them will scream bloody murder on
> cpa_lock and pgd_lock.
> 
> But if you want I can sprinkle more explicit warns 🙂

That's true. I was thinking of it more for self-documentation than
actually getting it to spit out warnings in practice.

Folks are always copying and pasting stuff and not realizing the context.