When a high-order page is split into smaller ones, each newly split page should get its codetag. The original codetag is reused for these pages but it's recorded as 0-byte allocation because original codetag already accounts for the original high-order allocated page.
Signed-off-by: Suren Baghdasaryan <[email protected]> --- include/linux/pgalloc_tag.h | 30 ++++++++++++++++++++++++++++++ mm/huge_memory.c | 2 ++ mm/page_alloc.c | 2 ++ 3 files changed, 34 insertions(+) diff --git a/include/linux/pgalloc_tag.h b/include/linux/pgalloc_tag.h index b49ab955300f..9e6ad8e0e4aa 100644 --- a/include/linux/pgalloc_tag.h +++ b/include/linux/pgalloc_tag.h @@ -67,11 +67,41 @@ static inline void pgalloc_tag_sub(struct page *page, unsigned int order) } } +static inline void pgalloc_tag_split(struct page *page, unsigned int nr) +{ + int i; + struct page_ext *page_ext; + union codetag_ref *ref; + struct alloc_tag *tag; + + if (!mem_alloc_profiling_enabled()) + return; + + page_ext = page_ext_get(page); + if (unlikely(!page_ext)) + return; + + ref = codetag_ref_from_page_ext(page_ext); + if (!ref->ct) + goto out; + + tag = ct_to_alloc_tag(ref->ct); + page_ext = page_ext_next(page_ext); + for (i = 1; i < nr; i++) { + /* Set new reference to point to the original tag */ + alloc_tag_ref_set(codetag_ref_from_page_ext(page_ext), tag); + page_ext = page_ext_next(page_ext); + } +out: + page_ext_put(page_ext); +} + #else /* CONFIG_MEM_ALLOC_PROFILING */ static inline void pgalloc_tag_add(struct page *page, struct task_struct *task, unsigned int order) {} static inline void pgalloc_tag_sub(struct page *page, unsigned int order) {} +static inline void pgalloc_tag_split(struct page *page, unsigned int nr) {} #endif /* CONFIG_MEM_ALLOC_PROFILING */ diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 94c958f7ebb5..86daae671319 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -38,6 +38,7 @@ #include <linux/sched/sysctl.h> #include <linux/memory-tiers.h> #include <linux/compat.h> +#include <linux/pgalloc_tag.h> #include <asm/tlb.h> #include <asm/pgalloc.h> @@ -2899,6 +2900,7 @@ static void __split_huge_page(struct page *page, struct list_head *list, /* Caller disabled irqs, so they are still disabled here */ split_page_owner(head, nr); + pgalloc_tag_split(head, nr); /* See comment in __split_huge_page_tail() */ if (PageAnon(head)) { diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 58c0e8b948a4..4bc5b4720fee 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2621,6 +2621,7 @@ void split_page(struct page *page, unsigned int order) for (i = 1; i < (1 << order); i++) set_page_refcounted(page + i); split_page_owner(page, 1 << order); + pgalloc_tag_split(page, 1 << order); split_page_memcg(page, 1 << order); } EXPORT_SYMBOL_GPL(split_page); @@ -4806,6 +4807,7 @@ static void *make_alloc_exact(unsigned long addr, unsigned int order, struct page *last = page + nr; split_page_owner(page, 1 << order); + pgalloc_tag_split(page, 1 << order); split_page_memcg(page, 1 << order); while (page < --last) set_page_refcounted(last); -- 2.44.0.rc0.258.g7320e95886-goog
