From 4bedfb314bdd85c1662ecc46fa25b33b998f994d Mon Sep 17 00:00:00 2001 From: Oscar Salvador Date: Thu, 15 Feb 2024 22:59:03 +0100 Subject: mm,page_owner: maintain own list of stack_records structs 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. Link: https://lkml.kernel.org/r/20240215215907.20121-4-osalvador@suse.de Signed-off-by: Oscar Salvador Reviewed-by: Vlastimil Babka Reviewed-by: Marco Elver Acked-by: Andrey Konovalov Cc: Alexander Potapenko Cc: Michal Hocko Signed-off-by: Andrew Morton --- include/linux/stackdepot.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'include/linux') diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h index c4b5ad57c066..3c6caa5abc7c 100644 --- a/include/linux/stackdepot.h +++ b/include/linux/stackdepot.h @@ -178,6 +178,17 @@ depot_stack_handle_t stack_depot_save_flags(unsigned long *entries, depot_stack_handle_t stack_depot_save(unsigned long *entries, unsigned int nr_entries, gfp_t gfp_flags); +/** + * __stack_depot_get_stack_record - Get a pointer to a stack_record struct + * + * @handle: Stack depot handle + * + * This function is only for internal purposes. + * + * Return: Returns a pointer to a stack_record struct + */ +struct stack_record *__stack_depot_get_stack_record(depot_stack_handle_t handle); + /** * stack_depot_fetch - Fetch a stack trace from stack depot * -- cgit v1.2.3