diff options
| -rw-r--r-- | mm/memcontrol.c | 220 |
1 files changed, 82 insertions, 138 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8ffec674c5a..61fd9590c13 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -95,6 +95,15 @@ static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat, return ret; } +static s64 mem_cgroup_local_usage(struct mem_cgroup_stat *stat) +{ + s64 ret; + + ret = mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_CACHE); + ret += mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_RSS); + return ret; +} + /* * per-zone information in memory controller. */ @@ -154,9 +163,9 @@ struct mem_cgroup { /* * While reclaiming in a hiearchy, we cache the last child we - * reclaimed from. Protected by hierarchy_mutex + * reclaimed from. */ - struct mem_cgroup *last_scanned_child; + int last_scanned_child; /* * Should the accounting and control be hierarchical, per subtree? */ @@ -629,103 +638,6 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, #define mem_cgroup_from_res_counter(counter, member) \ container_of(counter, struct mem_cgroup, member) -/* - * This routine finds the DFS walk successor. This routine should be - * called with hierarchy_mutex held - */ -static struct mem_cgroup * -__mem_cgroup_get_next_node(struct mem_cgroup *curr, struct mem_cgroup *root_mem) -{ - struct cgroup *cgroup, *curr_cgroup, *root_cgroup; - - curr_cgroup = curr->css.cgroup; - root_cgroup = root_mem->css.cgroup; - - if (!list_empty(&curr_cgroup->children)) { - /* - * Walk down to children - */ - cgroup = list_entry(curr_cgroup->children.next, - struct cgroup, sibling); - curr = mem_cgroup_from_cont(cgroup); - goto done; - } - -visit_parent: - if (curr_cgroup == root_cgroup) { - /* caller handles NULL case */ - curr = NULL; - goto done; - } - - /* - * Goto next sibling - */ - if (curr_cgroup->sibling.next != &curr_cgroup->parent->children) { - cgroup = list_entry(curr_cgroup->sibling.next, struct cgroup, - sibling); - curr = mem_cgroup_from_cont(cgroup); - goto done; - } - - /* - * Go up to next parent and next parent's sibling if need be - */ - curr_cgroup = curr_cgroup->parent; - goto visit_parent; - -done: - return curr; -} - -/* - * Visit the first child (need not be the first child as per the ordering - * of the cgroup list, since we track last_scanned_child) of @mem and use - * that to reclaim free pages from. - */ -static struct mem_cgroup * -mem_cgroup_get_next_node(struct mem_cgroup *root_mem) -{ - struct cgroup *cgroup; - struct mem_cgroup *orig, *next; - bool obsolete; - - /* - * Scan all children under the mem_cgroup mem - */ - mutex_lock(&mem_cgroup_subsys.hierarchy_mutex); - - orig = root_mem->last_scanned_child; - obsolete = mem_cgroup_is_obsolete(orig); - - if (list_empty(&root_mem->css.cgroup->children)) { - /* - * root_mem might have children before and last_scanned_child - * may point to one of them. We put it later. - */ - if (orig) - VM_BUG_ON(!obsolete); - next = NULL; - goto done; - } - - if (!orig || obsolete) { - cgroup = list_first_entry(&root_mem->css.cgroup->children, - struct cgroup, sibling); - next = mem_cgroup_from_cont(cgroup); - } else - next = __mem_cgroup_get_next_node(orig, root_mem); - -done: - if (next) - mem_cgroup_get(next); - root_mem->last_scanned_child = next; - if (orig) - mem_cgroup_put(orig); - mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex); - return (next) ? next : root_mem; -} - static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem) { if (do_swap_account) { @@ -755,46 +667,79 @@ static unsigned int get_swappiness(struct mem_cgroup *memcg) } /* - * Dance down the hierarchy if needed to reclaim memory. We remember the - * last child we reclaimed from, so that we don't end up penalizing - * one child extensively based on its position in the children list. + * Visit the first child (need not be the first child as per the ordering + * of the cgroup list, since we track last_scanned_child) of @mem and use + * that to reclaim free pages from. + */ +static struct mem_cgroup * +mem_cgroup_select_victim(struct mem_cgroup *root_mem) +{ + struct mem_cgroup *ret = NULL; + struct cgroup_subsys_state *css; + int nextid, found; + + if (!root_mem->use_hierarchy) { + css_get(&root_mem->css); + ret = root_mem; + } + + while (!ret) { + rcu_read_lock(); + nextid = root_mem->last_scanned_child + 1; + css = css_get_next(&mem_cgroup_subsys, nextid, &root_mem->css, + &found); + if (css && css_tryget(css)) + ret = container_of(css, struct mem_cgroup, css); + + rcu_read_unlock(); + /* Updates scanning parameter */ + spin_lock(&root_mem->reclaim_param_lock); + if (!css) { + /* this means start scan from ID:1 */ + root_mem->last_scanned_child = 0; + } else + root_mem->last_scanned_child = found; + spin_unlock(&root_mem->reclaim_param_lock); + } + + return ret; +} + +/* + * Scan the hierarchy if needed to reclaim memory. We remember the last child + * we reclaimed from, so that we don't end up penalizing one child extensively + * based on its position in the children list. * * root_mem is the original ancestor that we've been reclaim from. + * + * We give up and return to the caller when we visit root_mem twice. + * (other groups can be removed while we're walking....) */ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, gfp_t gfp_mask, bool noswap) { - struct mem_cgroup *next_mem; - int ret = 0; - - /* - * Reclaim unconditionally and don't check for return value. - * We need to reclaim in the current group and down the tree. - * One might think about checking for children before reclaiming, - * but there might be left over accounting, even after children - * have left. - */ - ret += try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap, - get_swappiness(root_mem)); - if (mem_cgroup_check_under_limit(root_mem)) - return 1; /* indicate reclaim has succeeded */ - if (!root_mem->use_hierarchy) - return ret; - - next_mem = mem_cgroup_get_next_node(root_mem); - - while (next_mem != root_mem) { - if (mem_cgroup_is_obsolete(next_mem)) { - next_mem = mem_cgroup_get_next_node(root_mem); + struct mem_cgroup *victim; + int ret, total = 0; + int loop = 0; + + while (loop < 2) { + victim = mem_cgroup_select_victim(root_mem); + if (victim == root_mem) + loop++; + if (!mem_cgroup_local_usage(&victim->stat)) { + /* this cgroup's local usage == 0 */ + css_put(&victim->css); continue; } - ret += try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap, - get_swappiness(next_mem)); + /* we use swappiness of local cgroup */ + ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, noswap, + get_swappiness(victim)); + css_put(&victim->css); + total += ret; if (mem_cgroup_check_under_limit(root_mem)) - return 1; /* indicate reclaim has succeeded */ - next_mem = mem_cgroup_get_next_node(root_mem); + return 1 + total; } - return ret; + return total; } bool mem_cgroup_oom_called(struct task_struct *task) @@ -1324,8 +1269,8 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) res_counter_uncharge(&mem->res, PAGE_SIZE); if (do_swap_account && (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT)) res_counter_uncharge(&mem->memsw, PAGE_SIZE); - mem_cgroup_charge_statistics(mem, pc, false); + ClearPageCgroupUsed(pc); /* * pc->mem_cgroup is not cleared here. It will be accessed when it's @@ -2178,6 +2123,8 @@ static void __mem_cgroup_free(struct mem_cgroup *mem) { int node; + free_css_id(&mem_cgroup_subsys, &mem->css); + for_each_node_state(node, N_POSSIBLE) free_mem_cgroup_per_zone_info(mem, node); @@ -2228,11 +2175,12 @@ static struct cgroup_subsys_state * __ref mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) { struct mem_cgroup *mem, *parent; + long error = -ENOMEM; int node; mem = mem_cgroup_alloc(); if (!mem) - return ERR_PTR(-ENOMEM); + return ERR_PTR(error); for_each_node_state(node, N_POSSIBLE) if (alloc_mem_cgroup_per_zone_info(mem, node)) @@ -2260,7 +2208,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) res_counter_init(&mem->res, NULL); res_counter_init(&mem->memsw, NULL); } - mem->last_scanned_child = NULL; + mem->last_scanned_child = 0; spin_lock_init(&mem->reclaim_param_lock); if (parent) @@ -2269,7 +2217,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) return &mem->css; free_out: __mem_cgroup_free(mem); - return ERR_PTR(-ENOMEM); + return ERR_PTR(error); } static int mem_cgroup_pre_destroy(struct cgroup_subsys *ss, @@ -2284,12 +2232,7 @@ static void mem_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cont) { struct mem_cgroup *mem = mem_cgroup_from_cont(cont); - struct mem_cgroup *last_scanned_child = mem->last_scanned_child; - if (last_scanned_child) { - VM_BUG_ON(!mem_cgroup_is_obsolete(last_scanned_child)); - mem_cgroup_put(last_scanned_child); - } mem_cgroup_put(mem); } @@ -2328,6 +2271,7 @@ struct cgroup_subsys mem_cgroup_subsys = { .populate = mem_cgroup_populate, .attach = mem_cgroup_move_task, .early_init = 0, + .use_id = 1, }; #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |