From: Sergei Trofimovich <slyfox@xxxxxxxxxx> Subject: mm: page_owner: fetch backtrace only for tracked pages Very minor optimization. Link: https://lkml.kernel.org/r/20210401212445.3534721-1-slyfox@xxxxxxxxxx Signed-off-by: Sergei Trofimovich <slyfox@xxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_owner.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/page_owner.c~mm-page_owner-fetch-backtrace-only-for-tracked-pages +++ a/mm/page_owner.c @@ -147,15 +147,15 @@ void __reset_page_owner(struct page *pag { int i; struct page_ext *page_ext; - depot_stack_handle_t handle = 0; + depot_stack_handle_t handle; struct page_owner *page_owner; u64 free_ts_nsec = local_clock(); - handle = save_stack(GFP_NOWAIT | __GFP_NOWARN); - page_ext = lookup_page_ext(page); if (unlikely(!page_ext)) return; + + handle = save_stack(GFP_NOWAIT | __GFP_NOWARN); for (i = 0; i < (1 << order); i++) { __clear_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags); page_owner = get_page_owner(page_ext); _
