Re: [PATCH v2 4/4] mm, page_owner, debug_pagealloc: save and dump freeing stack trace

[Kirill A. Shutemov]

On Tue, Sep 24, 2019 at 05:15:01PM +0200, Vlastimil Babka wrote:
> On 9/24/19 1:42 PM, Kirill A. Shutemov wrote:
> >> --- a/mm/page_owner.c
> >> +++ b/mm/page_owner.c
> >> @@ -24,6 +24,9 @@ struct page_owner {
> >>  	short last_migrate_reason;
> >>  	gfp_t gfp_mask;
> >>  	depot_stack_handle_t handle;
> >> +#ifdef CONFIG_DEBUG_PAGEALLOC
> >> +	depot_stack_handle_t free_handle;
> >> +#endif
> > 
> > I think it's possible to add space for the second stack handle at runtime:
> > adjust page_owner_ops->size inside the ->need().
> 
> Uh that would complicate the code needlessly? The extra memory overhead
> isn't that much for a scenario that's already a debugging one
> (page_owner), I was more concerned about the cpu overhead, thus the
> static key.

Okay, fair enough.

-- 
 Kirill A. Shutemov