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

[Vlastimil Babka]

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>