diff --git a/include/linux/swap.h b/include/linux/swap.h index dca9b9999aeb..c88b36665f79 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -319,10 +319,11 @@ static inline void disable_swap_token(void) } #ifdef CONFIG_CGROUP_MEM_RES_CTLR -extern void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent); +extern void +mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout); #else static inline void -mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) +mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) { } #endif diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 3468c38adde6..a83e0395444b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -189,6 +189,7 @@ enum charge_type { MEM_CGROUP_CHARGE_TYPE_SHMEM, /* used by page migration of shmem */ MEM_CGROUP_CHARGE_TYPE_FORCE, /* used by force_empty */ MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */ + MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */ NR_CHARGE_TYPE, }; @@ -1493,6 +1494,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) switch (ctype) { case MEM_CGROUP_CHARGE_TYPE_MAPPED: + case MEM_CGROUP_CHARGE_TYPE_DROP: if (page_mapped(page)) goto unlock_out; break; @@ -1556,18 +1558,23 @@ void mem_cgroup_uncharge_cache_page(struct page *page) * called after __delete_from_swap_cache() and drop "page" account. * memcg information is recorded to swap_cgroup of "ent" */ -void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) +void +mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) { struct mem_cgroup *memcg; + int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT; + + if (!swapout) /* this was a swap cache but the swap is unused ! */ + ctype = MEM_CGROUP_CHARGE_TYPE_DROP; + + memcg = __mem_cgroup_uncharge_common(page, ctype); - memcg = __mem_cgroup_uncharge_common(page, - MEM_CGROUP_CHARGE_TYPE_SWAPOUT); /* record memcg information */ - if (do_swap_account && memcg) { + if (do_swap_account && swapout && memcg) { swap_cgroup_record(ent, css_id(&memcg->css)); mem_cgroup_get(memcg); } - if (memcg) + if (swapout && memcg) css_put(&memcg->css); } #endif diff --git a/mm/swapfile.c b/mm/swapfile.c index 28faa01cf578..d1ade1a48ee7 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -583,8 +583,9 @@ static int swap_entry_free(struct swap_info_struct *p, swap_list.next = p - swap_info; nr_swap_pages++; p->inuse_pages--; - mem_cgroup_uncharge_swap(ent); } + if (!swap_count(count)) + mem_cgroup_uncharge_swap(ent); return count; } @@ -609,12 +610,19 @@ void swap_free(swp_entry_t entry) void swapcache_free(swp_entry_t entry, struct page *page) { struct swap_info_struct *p; + int ret; - if (page) - mem_cgroup_uncharge_swapcache(page, entry); p = swap_info_get(entry); if (p) { - swap_entry_free(p, entry, SWAP_CACHE); + ret = swap_entry_free(p, entry, SWAP_CACHE); + if (page) { + bool swapout; + if (ret) + swapout = true; /* the end of swap out */ + else + swapout = false; /* no more swap users! */ + mem_cgroup_uncharge_swapcache(page, entry, swapout); + } spin_unlock(&swap_lock); } return;