On 13 Nov 2020, at 19:23, Roman Gushchin wrote:
On Wed, Nov 11, 2020 at 03:40:04PM -0500, Zi Yan wrote:
From: Zi Yan ziy@nvidia.com
It reads thp_nr_pages and splits to provided new_nr. It prepares for upcoming changes to support split huge page to any lower order.
Signed-off-by: Zi Yan ziy@nvidia.com
include/linux/memcontrol.h | 5 +++-- mm/huge_memory.c | 2 +- mm/memcontrol.c | 4 ++-- 3 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 0f4dd7829fb2..b3bac79ceed6 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1105,7 +1105,7 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm, }
#ifdef CONFIG_TRANSPARENT_HUGEPAGE -void mem_cgroup_split_huge_fixup(struct page *head); +void mem_cgroup_split_huge_fixup(struct page *head, unsigned int new_nr); #endif
#else /* CONFIG_MEMCG */ @@ -1451,7 +1451,8 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, return 0; }
-static inline void mem_cgroup_split_huge_fixup(struct page *head) +static inline void mem_cgroup_split_huge_fixup(struct page *head,
unsigned int new_nr){ }
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index c4fead5ead31..f599f5b9bf7f 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2429,7 +2429,7 @@ static void __split_huge_page(struct page *page, struct list_head *list, lruvec = mem_cgroup_page_lruvec(head, pgdat);
/* complete memcg works before add pages to LRU */
- mem_cgroup_split_huge_fixup(head);
mem_cgroup_split_huge_fixup(head, 1);
if (PageAnon(head) && PageSwapCache(head)) { swp_entry_t entry = { .val = page_private(head) };
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 33f632689cee..e9705ba6bbcc 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3247,7 +3247,7 @@ void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size)
- Because tail pages are not marked as "used", set it. We're under
- pgdat->lru_lock and migration entries setup in all page mappings.
*/ -void mem_cgroup_split_huge_fixup(struct page *head) +void mem_cgroup_split_huge_fixup(struct page *head, unsigned int new_nr)
I'd go with unsigned int new_order, then it's obvious that we can split the original page without any leftovers.
Makes sense. Will change it.
Other than that the patch looks good! Acked-by: Roman Gushchin guro@fb.com
Thanks.
{ struct mem_cgroup *memcg = page_memcg(head); int i; @@ -3255,7 +3255,7 @@ void mem_cgroup_split_huge_fixup(struct page *head) if (mem_cgroup_disabled()) return;
- for (i = 1; i < thp_nr_pages(head); i++) {
- for (i = new_nr; i < thp_nr_pages(head); i += new_nr) { css_get(&memcg->css); head[i].memcg_data = (unsigned long)memcg; }
-- 2.28.0
— Best Regards, Yan Zi