From 90254a65833b67502d14736410b3857a15535c67 Mon Sep 17 00:00:00 2001 From: Daisuke Nishimura Date: Wed, 26 May 2010 14:42:38 -0700 Subject: [PATCH] memcg: clean up move charge This patch cleans up move charge code by: - define functions to handle pte for each types, and make is_target_pte_for_mc() cleaner. - instead of checking the MOVE_CHARGE_TYPE_ANON bit, define a function that checks the bit. Signed-off-by: Daisuke Nishimura Acked-by: KAMEZAWA Hiroyuki Cc: Balbir Singh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 96 ++++++++++++++++++++++++++++++------------------- 1 file changed, 59 insertions(+), 37 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 53eb30ebdb49..e5277e8a42a8 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -266,6 +266,12 @@ static struct move_charge_struct { .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), }; +static bool move_anon(void) +{ + return test_bit(MOVE_CHARGE_TYPE_ANON, + &mc.to->move_charge_at_immigrate); +} + /* * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft * limit reclaim to prevent infinite loops, if they ever occur. @@ -4162,50 +4168,66 @@ enum mc_target_type { MC_TARGET_SWAP, }; -static int is_target_pte_for_mc(struct vm_area_struct *vma, - unsigned long addr, pte_t ptent, union mc_target *target) +static struct page *mc_handle_present_pte(struct vm_area_struct *vma, + unsigned long addr, pte_t ptent) { - struct page *page = NULL; - struct page_cgroup *pc; - int ret = 0; - swp_entry_t ent = { .val = 0 }; - int usage_count = 0; - bool move_anon = test_bit(MOVE_CHARGE_TYPE_ANON, - &mc.to->move_charge_at_immigrate); + struct page *page = vm_normal_page(vma, addr, ptent); - if (!pte_present(ptent)) { - /* TODO: handle swap of shmes/tmpfs */ - if (pte_none(ptent) || pte_file(ptent)) - return 0; - else if (is_swap_pte(ptent)) { - ent = pte_to_swp_entry(ptent); - if (!move_anon || non_swap_entry(ent)) - return 0; - usage_count = mem_cgroup_count_swap_user(ent, &page); - } - } else { - page = vm_normal_page(vma, addr, ptent); - if (!page || !page_mapped(page)) - return 0; + if (!page || !page_mapped(page)) + return NULL; + if (PageAnon(page)) { + /* we don't move shared anon */ + if (!move_anon() || page_mapcount(page) > 2) + return NULL; + } else /* * TODO: We don't move charges of file(including shmem/tmpfs) * pages for now. */ - if (!move_anon || !PageAnon(page)) - return 0; - if (!get_page_unless_zero(page)) - return 0; - usage_count = page_mapcount(page); - } - if (usage_count > 1) { - /* - * TODO: We don't move charges of shared(used by multiple - * processes) pages for now. - */ + return NULL; + if (!get_page_unless_zero(page)) + return NULL; + + return page; +} + +static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, + unsigned long addr, pte_t ptent, swp_entry_t *entry) +{ + int usage_count; + struct page *page = NULL; + swp_entry_t ent = pte_to_swp_entry(ptent); + + if (!move_anon() || non_swap_entry(ent)) + return NULL; + usage_count = mem_cgroup_count_swap_user(ent, &page); + if (usage_count > 1) { /* we don't move shared anon */ if (page) put_page(page); - return 0; + return NULL; } + if (do_swap_account) + entry->val = ent.val; + + return page; +} + +static int is_target_pte_for_mc(struct vm_area_struct *vma, + unsigned long addr, pte_t ptent, union mc_target *target) +{ + struct page *page = NULL; + struct page_cgroup *pc; + int ret = 0; + swp_entry_t ent = { .val = 0 }; + + if (pte_present(ptent)) + page = mc_handle_present_pte(vma, addr, ptent); + else if (is_swap_pte(ptent)) + page = mc_handle_swap_pte(vma, addr, ptent, &ent); + /* TODO: handle swap of shmes/tmpfs */ + + if (!page && !ent.val) + return 0; if (page) { pc = lookup_page_cgroup(page); /* @@ -4221,8 +4243,8 @@ static int is_target_pte_for_mc(struct vm_area_struct *vma, if (!ret || !target) put_page(page); } - /* throught */ - if (ent.val && do_swap_account && !ret && + /* There is a swap entry and a page doesn't exist or isn't charged */ + if (ent.val && !ret && css_id(&mc.from->css) == lookup_swap_cgroup(ent)) { ret = MC_TARGET_SWAP; if (target) -- GitLab