Re: [PATCH v9 3/7] mm,page_owner: Maintain own list of stack_records structs

From: Marco Elver
Date: Thu Feb 15 2024 - 07:56:52 EST


On Thu, 15 Feb 2024 at 11:55, Vlastimil Babka <vbabka@xxxxxxx> wrote:
>
> On 2/14/24 18:01, Oscar Salvador wrote:
> > page_owner needs to increment a stack_record refcount when a new allocation
> > occurs, and decrement it on a free operation.
> > In order to do that, we need to have a way to get a stack_record from a
> > handle.
> > Implement __stack_depot_get_stack_record() which just does that, and make
> > it public so page_owner can use it.
> >
> > Also, traversing all stackdepot buckets comes with its own complexity,
> > plus we would have to implement a way to mark only those stack_records
> > that were originated from page_owner, as those are the ones we are
> > interested in.
> > For that reason, page_owner maintains its own list of stack_records,
> > because traversing that list is faster than traversing all buckets
> > while keeping at the same time a low complexity.
> >
> > For now, add to stack_list only the stack_records of dummy_handle and
> > failure_handle, and set their refcount of 1.
> >
> > Further patches will add code to increment or decrement stack_records
> > count on allocation and free operation.
> >
> > Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
>
> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
>

+1

Reviewed-by: Marco Elver <elver@xxxxxxxxxx>