From 42895a86124418d8dd29a93812bc282e569ccfee Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Wed, 23 Oct 2024 10:07:58 -0700 Subject: [PATCH] alloc_tag: introduce pgtag_ref_handle to abstract page tag references To simplify later changes to page tag references, introduce new pgtag_ref_handle type. This allows easy replacement of page_ext as a storage of page allocation tags. Link: https://lkml.kernel.org/r/20241023170759.999909-6-surenb@google.com Signed-off-by: Suren Baghdasaryan Reviewed-by: Pasha Tatashin Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: Borislav Petkov (AMD) Cc: Christoph Hellwig Cc: Daniel Gomez Cc: David Hildenbrand Cc: Davidlohr Bueso Cc: David Rientjes Cc: Dennis Zhou Cc: Johannes Weiner Cc: John Hubbard Cc: Jonathan Corbet Cc: Joonsoo Kim Cc: Kalesh Singh Cc: Kees Cook Cc: Kent Overstreet Cc: Liam R. Howlett Cc: Luis Chamberlain Cc: Matthew Wilcox Cc: Michal Hocko Cc: Mike Rapoport (Microsoft) Cc: Minchan Kim Cc: Paul E. McKenney Cc: Petr Pavlu Cc: Roman Gushchin Cc: Sami Tolvanen Cc: Sourav Panda Cc: Steven Rostedt (Google) Cc: Thomas Gleixner Cc: Thomas Huth Cc: Uladzislau Rezki (Sony) Cc: Vlastimil Babka Cc: Xiongwei Song Cc: Yu Zhao Signed-off-by: Andrew Morton --- include/linux/mm.h | 25 +++++----- include/linux/pgalloc_tag.h | 96 +++++++++++++++++++++---------------- 2 files changed, 69 insertions(+), 52 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index eb070c14e309..f9120ac6d901 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -4181,37 +4181,38 @@ static inline void pgalloc_tag_split(struct folio *folio, int old_order, int new return; for (i = nr_pages; i < (1 << old_order); i += nr_pages) { - union codetag_ref *ref = get_page_tag_ref(folio_page(folio, i)); + union pgtag_ref_handle handle; + union codetag_ref ref; - if (ref) { + if (get_page_tag_ref(folio_page(folio, i), &ref, &handle)) { /* Set new reference to point to the original tag */ - alloc_tag_ref_set(ref, tag); - put_page_tag_ref(ref); + alloc_tag_ref_set(&ref, tag); + update_page_tag_ref(handle, &ref); + put_page_tag_ref(handle); } } } static inline void pgalloc_tag_copy(struct folio *new, struct folio *old) { + union pgtag_ref_handle handle; + union codetag_ref ref; struct alloc_tag *tag; - union codetag_ref *ref; tag = pgalloc_tag_get(&old->page); if (!tag) return; - ref = get_page_tag_ref(&new->page); - if (!ref) + if (!get_page_tag_ref(&new->page, &ref, &handle)) return; /* Clear the old ref to the original allocation tag. */ clear_page_tag_ref(&old->page); /* Decrement the counters of the tag on get_new_folio. */ - alloc_tag_sub(ref, folio_size(new)); - - __alloc_tag_ref_set(ref, tag); - - put_page_tag_ref(ref); + alloc_tag_sub(&ref, folio_size(new)); + __alloc_tag_ref_set(&ref, tag); + update_page_tag_ref(handle, &ref); + put_page_tag_ref(handle); } #else /* !CONFIG_MEM_ALLOC_PROFILING */ static inline void pgalloc_tag_split(struct folio *folio, int old_order, int new_order) diff --git a/include/linux/pgalloc_tag.h b/include/linux/pgalloc_tag.h index 59a3deb792a8..b13cd3313a88 100644 --- a/include/linux/pgalloc_tag.h +++ b/include/linux/pgalloc_tag.h @@ -11,46 +11,59 @@ #include +union pgtag_ref_handle { + union codetag_ref *ref; /* reference in page extension */ +}; + extern struct page_ext_operations page_alloc_tagging_ops; -static inline union codetag_ref *codetag_ref_from_page_ext(struct page_ext *page_ext) -{ - return (union codetag_ref *)page_ext_data(page_ext, &page_alloc_tagging_ops); -} - -static inline struct page_ext *page_ext_from_codetag_ref(union codetag_ref *ref) -{ - return (void *)ref - page_alloc_tagging_ops.offset; -} - /* Should be called only if mem_alloc_profiling_enabled() */ -static inline union codetag_ref *get_page_tag_ref(struct page *page) +static inline bool get_page_tag_ref(struct page *page, union codetag_ref *ref, + union pgtag_ref_handle *handle) { - if (page) { - struct page_ext *page_ext = page_ext_get(page); + struct page_ext *page_ext; + union codetag_ref *tmp; - if (page_ext) - return codetag_ref_from_page_ext(page_ext); - } - return NULL; + if (!page) + return false; + + page_ext = page_ext_get(page); + if (!page_ext) + return false; + + tmp = (union codetag_ref *)page_ext_data(page_ext, &page_alloc_tagging_ops); + ref->ct = tmp->ct; + handle->ref = tmp; + return true; } -static inline void put_page_tag_ref(union codetag_ref *ref) +static inline void put_page_tag_ref(union pgtag_ref_handle handle) { - if (WARN_ON(!ref)) + if (WARN_ON(!handle.ref)) return; - page_ext_put(page_ext_from_codetag_ref(ref)); + page_ext_put((void *)handle.ref - page_alloc_tagging_ops.offset); +} + +static inline void update_page_tag_ref(union pgtag_ref_handle handle, + union codetag_ref *ref) +{ + if (WARN_ON(!handle.ref || !ref)) + return; + + handle.ref->ct = ref->ct; } static inline void clear_page_tag_ref(struct page *page) { if (mem_alloc_profiling_enabled()) { - union codetag_ref *ref = get_page_tag_ref(page); + union pgtag_ref_handle handle; + union codetag_ref ref; - if (ref) { - set_codetag_empty(ref); - put_page_tag_ref(ref); + if (get_page_tag_ref(page, &ref, &handle)) { + set_codetag_empty(&ref); + update_page_tag_ref(handle, &ref); + put_page_tag_ref(handle); } } } @@ -59,11 +72,13 @@ static inline void pgalloc_tag_add(struct page *page, struct task_struct *task, unsigned int nr) { if (mem_alloc_profiling_enabled()) { - union codetag_ref *ref = get_page_tag_ref(page); + union pgtag_ref_handle handle; + union codetag_ref ref; - if (ref) { - alloc_tag_add(ref, task->alloc_tag, PAGE_SIZE * nr); - put_page_tag_ref(ref); + if (get_page_tag_ref(page, &ref, &handle)) { + alloc_tag_add(&ref, task->alloc_tag, PAGE_SIZE * nr); + update_page_tag_ref(handle, &ref); + put_page_tag_ref(handle); } } } @@ -71,11 +86,13 @@ static inline void pgalloc_tag_add(struct page *page, struct task_struct *task, static inline void pgalloc_tag_sub(struct page *page, unsigned int nr) { if (mem_alloc_profiling_enabled()) { - union codetag_ref *ref = get_page_tag_ref(page); + union pgtag_ref_handle handle; + union codetag_ref ref; - if (ref) { - alloc_tag_sub(ref, PAGE_SIZE * nr); - put_page_tag_ref(ref); + if (get_page_tag_ref(page, &ref, &handle)) { + alloc_tag_sub(&ref, PAGE_SIZE * nr); + update_page_tag_ref(handle, &ref); + put_page_tag_ref(handle); } } } @@ -85,13 +102,14 @@ static inline struct alloc_tag *pgalloc_tag_get(struct page *page) struct alloc_tag *tag = NULL; if (mem_alloc_profiling_enabled()) { - union codetag_ref *ref = get_page_tag_ref(page); + union pgtag_ref_handle handle; + union codetag_ref ref; - alloc_tag_sub_check(ref); - if (ref) { - if (ref->ct) - tag = ct_to_alloc_tag(ref->ct); - put_page_tag_ref(ref); + if (get_page_tag_ref(page, &ref, &handle)) { + alloc_tag_sub_check(&ref); + if (ref.ct) + tag = ct_to_alloc_tag(ref.ct); + put_page_tag_ref(handle); } } @@ -106,8 +124,6 @@ static inline void pgalloc_tag_sub_pages(struct alloc_tag *tag, unsigned int nr) #else /* CONFIG_MEM_ALLOC_PROFILING */ -static inline union codetag_ref *get_page_tag_ref(struct page *page) { return NULL; } -static inline void put_page_tag_ref(union codetag_ref *ref) {} static inline void clear_page_tag_ref(struct page *page) {} static inline void pgalloc_tag_add(struct page *page, struct task_struct *task, unsigned int nr) {}