Messages in this thread | | | Date | Fri, 5 Mar 2021 12:48:00 +0100 | From | Michal Hocko <> | Subject | Re: [PATCH v2 1/2] mm/memcg: rename mem_cgroup_split_huge_fixup to split_page_memcg |
| |
On Thu 04-03-21 07:40:52, Zhou Guanghui wrote: > Rename mem_cgroup_split_huge_fixup to split_page_memcg and explicitly > pass in page number argument. > > In this way, the interface name is more common and can be used by > potential users. In addition, the complete info(memcg and flag) of > the memcg needs to be set to the tail pages.
I think it is good to call out the css_get -> css_get_many as a microptimization explicitly. Even though I do not expect this to be easily visible it makes sense to save rcu section for each of the tail page in general.
> Signed-off-by: Zhou Guanghui <zhouguanghui1@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
> --- > include/linux/memcontrol.h | 6 ++---- > mm/huge_memory.c | 2 +- > mm/memcontrol.c | 15 ++++++--------- > 3 files changed, 9 insertions(+), 14 deletions(-) > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index e6dc793d587d..0c04d39a7967 100644 > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -1061,9 +1061,7 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm, > rcu_read_unlock(); > } > > -#ifdef CONFIG_TRANSPARENT_HUGEPAGE > -void mem_cgroup_split_huge_fixup(struct page *head); > -#endif > +void split_page_memcg(struct page *head, unsigned int nr); > > #else /* CONFIG_MEMCG */ > > @@ -1400,7 +1398,7 @@ 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 split_page_memcg(struct page *head, unsigned int nr) > { > } > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 395c75111d33..e7f29308ebc8 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -2471,7 +2471,7 @@ static void __split_huge_page(struct page *page, struct list_head *list, > int i; > > /* complete memcg works before add pages to LRU */ > - mem_cgroup_split_huge_fixup(head); > + split_page_memcg(head, nr); > > if (PageAnon(head) && PageSwapCache(head)) { > swp_entry_t entry = { .val = page_private(head) }; > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 845eec01ef9d..e064ac0d850a 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -3287,24 +3287,21 @@ void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size) > > #endif /* CONFIG_MEMCG_KMEM */ > > -#ifdef CONFIG_TRANSPARENT_HUGEPAGE > /* > - * Because page_memcg(head) is not set on compound tails, set it now. > + * Because page_memcg(head) is not set on tails, set it now. > */ > -void mem_cgroup_split_huge_fixup(struct page *head) > +void split_page_memcg(struct page *head, unsigned int nr) > { > struct mem_cgroup *memcg = page_memcg(head); > int i; > > - if (mem_cgroup_disabled()) > + if (mem_cgroup_disabled() || !memcg) > return; > > - for (i = 1; i < HPAGE_PMD_NR; i++) { > - css_get(&memcg->css); > - head[i].memcg_data = (unsigned long)memcg; > - } > + for (i = 1; i < nr; i++) > + head[i].memcg_data = head->memcg_data; > + css_get_many(&memcg->css, nr - 1); > } > -#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ > > #ifdef CONFIG_MEMCG_SWAP > /** > -- > 2.25.0 >
-- Michal Hocko SUSE Labs
| |