diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memcontrol.c | 560 | ||||
| -rw-r--r-- | mm/vmscan.c | 83 |
2 files changed, 438 insertions, 205 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d5ff3ce13029..1c52ddbc839b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -39,6 +39,7 @@ #include <linux/limits.h> #include <linux/export.h> #include <linux/mutex.h> +#include <linux/rbtree.h> #include <linux/slab.h> #include <linux/swap.h> #include <linux/swapops.h> @@ -160,6 +161,10 @@ struct mem_cgroup_per_zone { struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1]; + struct rb_node tree_node; /* RB tree node */ + unsigned long long usage_in_excess;/* Set to the value by which */ + /* the soft limit is exceeded*/ + bool on_tree; struct mem_cgroup *memcg; /* Back pointer, we cannot */ /* use container_of */ }; @@ -168,6 +173,26 @@ struct mem_cgroup_per_node { struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES]; }; +/* + * Cgroups above their limits are maintained in a RB-Tree, independent of + * their hierarchy representation + */ + +struct mem_cgroup_tree_per_zone { + struct rb_root rb_root; + spinlock_t lock; +}; + +struct mem_cgroup_tree_per_node { + struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES]; +}; + +struct mem_cgroup_tree { + struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; +}; + +static struct mem_cgroup_tree soft_limit_tree __read_mostly; + struct mem_cgroup_threshold { struct eventfd_ctx *eventfd; u64 threshold; @@ -303,22 +328,6 @@ struct mem_cgroup { atomic_t numainfo_events; atomic_t numainfo_updating; #endif - /* - * Protects soft_contributed transitions. - * See mem_cgroup_update_soft_limit - */ - spinlock_t soft_lock; - - /* - * If true then this group has increased parents' children_in_excess - * when it got over the soft limit. - * When a group falls bellow the soft limit, parents' children_in_excess - * is decreased and soft_contributed changed to false. - */ - bool soft_contributed; - - /* Number of children that are in soft limit excess */ - atomic_t children_in_excess; struct mem_cgroup_per_node *nodeinfo[0]; /* WARNING: nodeinfo must be the last member here */ @@ -422,6 +431,7 @@ static bool move_file(void) * limit reclaim to prevent infinite loops, if they ever occur. */ #define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 +#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 enum charge_type { MEM_CGROUP_CHARGE_TYPE_CACHE = 0, @@ -648,6 +658,164 @@ page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page) return mem_cgroup_zoneinfo(memcg, nid, zid); } +static struct mem_cgroup_tree_per_zone * +soft_limit_tree_node_zone(int nid, int zid) +{ + return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; +} + +static struct mem_cgroup_tree_per_zone * +soft_limit_tree_from_page(struct page *page) +{ + int nid = page_to_nid(page); + int zid = page_zonenum(page); + + return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid]; +} + +static void +__mem_cgroup_insert_exceeded(struct mem_cgroup *memcg, + struct mem_cgroup_per_zone *mz, + struct mem_cgroup_tree_per_zone *mctz, + unsigned long long new_usage_in_excess) +{ + struct rb_node **p = &mctz->rb_root.rb_node; + struct rb_node *parent = NULL; + struct mem_cgroup_per_zone *mz_node; + + if (mz->on_tree) + return; + + mz->usage_in_excess = new_usage_in_excess; + if (!mz->usage_in_excess) + return; + while (*p) { + parent = *p; + mz_node = rb_entry(parent, struct mem_cgroup_per_zone, + tree_node); + if (mz->usage_in_excess < mz_node->usage_in_excess) + p = &(*p)->rb_left; + /* + * We can't avoid mem cgroups that are over their soft + * limit by the same amount + */ + else if (mz->usage_in_excess >= mz_node->usage_in_excess) + p = &(*p)->rb_right; + } + rb_link_node(&mz->tree_node, parent, p); + rb_insert_color(&mz->tree_node, &mctz->rb_root); + mz->on_tree = true; +} + +static void +__mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, + struct mem_cgroup_per_zone *mz, + struct mem_cgroup_tree_per_zone *mctz) +{ + if (!mz->on_tree) + return; + rb_erase(&mz->tree_node, &mctz->rb_root); + mz->on_tree = false; +} + +static void +mem_cgroup_remove_exceeded(struct mem_cgroup *memcg, + struct mem_cgroup_per_zone *mz, + struct mem_cgroup_tree_per_zone *mctz) +{ + spin_lock(&mctz->lock); + __mem_cgroup_remove_exceeded(memcg, mz, mctz); + spin_unlock(&mctz->lock); +} + + +static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page) +{ + unsigned long long excess; + struct mem_cgroup_per_zone *mz; + struct mem_cgroup_tree_per_zone *mctz; + int nid = page_to_nid(page); + int zid = page_zonenum(page); + mctz = soft_limit_tree_from_page(page); + + /* + * Necessary to update all ancestors when hierarchy is used. + * because their event counter is not touched. + */ + for (; memcg; memcg = parent_mem_cgroup(memcg)) { + mz = mem_cgroup_zoneinfo(memcg, nid, zid); + excess = res_counter_soft_limit_excess(&memcg->res); + /* + * We have to update the tree if mz is on RB-tree or + * mem is over its softlimit. + */ + if (excess || mz->on_tree) { + spin_lock(&mctz->lock); + /* if on-tree, remove it */ + if (mz->on_tree) + __mem_cgroup_remove_exceeded(memcg, mz, mctz); + /* + * Insert again. mz->usage_in_excess will be updated. + * If excess is 0, no tree ops. + */ + __mem_cgroup_insert_exceeded(memcg, mz, mctz, excess); + spin_unlock(&mctz->lock); + } + } +} + +static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) +{ + int node, zone; + struct mem_cgroup_per_zone *mz; + struct mem_cgroup_tree_per_zone *mctz; + + for_each_node(node) { + for (zone = 0; zone < MAX_NR_ZONES; zone++) { + mz = mem_cgroup_zoneinfo(memcg, node, zone); + mctz = soft_limit_tree_node_zone(node, zone); + mem_cgroup_remove_exceeded(memcg, mz, mctz); + } + } +} + +static struct mem_cgroup_per_zone * +__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) +{ + struct rb_node *rightmost = NULL; + struct mem_cgroup_per_zone *mz; + +retry: + mz = NULL; + rightmost = rb_last(&mctz->rb_root); + if (!rightmost) + goto done; /* Nothing to reclaim from */ + + mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node); + /* + * Remove the node now but someone else can add it back, + * we will to add it back at the end of reclaim to its correct + * position in the tree. + */ + __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); + if (!res_counter_soft_limit_excess(&mz->memcg->res) || + !css_tryget(&mz->memcg->css)) + goto retry; +done: + return mz; +} + +static struct mem_cgroup_per_zone * +mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz) +{ + struct mem_cgroup_per_zone *mz; + + spin_lock(&mctz->lock); + mz = __mem_cgroup_largest_soft_limit_node(mctz); + spin_unlock(&mctz->lock); + return mz; +} + /* * Implementation Note: reading percpu statistics for memcg. * @@ -822,48 +990,6 @@ static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, } /* - * Called from rate-limited memcg_check_events when enough - * MEM_CGROUP_TARGET_SOFTLIMIT events are accumulated and it makes sure - * that all the parents up the hierarchy will be notified that this group - * is in excess or that it is not in excess anymore. mmecg->soft_contributed - * makes the transition a single action whenever the state flips from one to - * the other. - */ -static void mem_cgroup_update_soft_limit(struct mem_cgroup *memcg) -{ - unsigned long long excess = res_counter_soft_limit_excess(&memcg->res); - struct mem_cgroup *parent = memcg; - int delta = 0; - - spin_lock(&memcg->soft_lock); - if (excess) { - if (!memcg->soft_contributed) { - delta = 1; - memcg->soft_contributed = true; - } - } else { - if (memcg->soft_contributed) { - delta = -1; - memcg->soft_contributed = false; - } - } - - /* - * Necessary to update all ancestors when hierarchy is used - * because their event counter is not touched. - * We track children even outside the hierarchy for the root - * cgroup because tree walk starting at root should visit - * all cgroups and we want to prevent from pointless tree - * walk if no children is below the limit. - */ - while (delta && (parent = parent_mem_cgroup(parent))) - atomic_add(delta, &parent->children_in_excess); - if (memcg != root_mem_cgroup && !root_mem_cgroup->use_hierarchy) - atomic_add(delta, &root_mem_cgroup->children_in_excess); - spin_unlock(&memcg->soft_lock); -} - -/* * Check events in order. * */ @@ -886,7 +1012,7 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page) mem_cgroup_threshold(memcg); if (unlikely(do_softlimit)) - mem_cgroup_update_soft_limit(memcg); + mem_cgroup_update_tree(memcg, page); #if MAX_NUMNODES > 1 if (unlikely(do_numainfo)) atomic_inc(&memcg->numainfo_events); @@ -929,15 +1055,6 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) return memcg; } -static enum mem_cgroup_filter_t -mem_cgroup_filter(struct mem_cgroup *memcg, struct mem_cgroup *root, - mem_cgroup_iter_filter cond) -{ - if (!cond) - return VISIT; - return cond(memcg, root); -} - /* * Returns a next (in a pre-order walk) alive memcg (with elevated css * ref. count) or NULL if the whole root's subtree has been visited. @@ -945,7 +1062,7 @@ mem_cgroup_filter(struct mem_cgroup *memcg, struct mem_cgroup *root, * helper function to be used by mem_cgroup_iter */ static struct mem_cgroup *__mem_cgroup_iter_next(struct mem_cgroup *root, - struct mem_cgroup *last_visited, mem_cgroup_iter_filter cond) + struct mem_cgroup *last_visited) { struct cgroup_subsys_state *prev_css, *next_css; @@ -963,31 +1080,11 @@ skip_node: if (next_css) { struct mem_cgroup *mem = mem_cgroup_from_css(next_css); - switch (mem_cgroup_filter(mem, root, cond)) { - case SKIP: + if (css_tryget(&mem->css)) + return mem; + else { prev_css = next_css; goto skip_node; - case SKIP_TREE: - if (mem == root) - return NULL; - /* - * css_rightmost_descendant is not an optimal way to - * skip through a subtree (especially for imbalanced - * trees leaning to right) but that's what we have right - * now. More effective solution would be traversing - * right-up for first non-NULL without calling - * css_next_descendant_pre afterwards. - */ - prev_css = css_rightmost_descendant(next_css); - goto skip_node; - case VISIT: - if (css_tryget(&mem->css)) - return mem; - else { - prev_css = next_css; - goto skip_node; - } - break; } } @@ -1051,7 +1148,6 @@ static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter, * @root: hierarchy root * @prev: previously returned memcg, NULL on first invocation * @reclaim: cookie for shared reclaim walks, NULL for full walks - * @cond: filter for visited nodes, NULL for no filter * * Returns references to children of the hierarchy below @root, or * @root itself, or %NULL after a full round-trip. @@ -1064,18 +1160,15 @@ static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter, * divide up the memcgs in the hierarchy among all concurrent * reclaimers operating on the same zone and priority. */ -struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root, +struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, struct mem_cgroup *prev, - struct mem_cgroup_reclaim_cookie *reclaim, - mem_cgroup_iter_filter cond) + struct mem_cgroup_reclaim_cookie *reclaim) { struct mem_cgroup *memcg = NULL; struct mem_cgroup *last_visited = NULL; - if (mem_cgroup_disabled()) { - /* first call must return non-NULL, second return NULL */ - return (struct mem_cgroup *)(unsigned long)!prev; - } + if (mem_cgroup_disabled()) + return NULL; if (!root) root = root_mem_cgroup; @@ -1086,9 +1179,7 @@ struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root, if (!root->use_hierarchy && root != root_mem_cgroup) { if (prev) goto out_css_put; - if (mem_cgroup_filter(root, root, cond) == VISIT) - return root; - return NULL; + return root; } rcu_read_lock(); @@ -1111,7 +1202,7 @@ struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root, last_visited = mem_cgroup_iter_load(iter, root, &seq); } - memcg = __mem_cgroup_iter_next(root, last_visited, cond); + memcg = __mem_cgroup_iter_next(root, last_visited); if (reclaim) { mem_cgroup_iter_update(iter, last_visited, memcg, seq); @@ -1122,11 +1213,7 @@ struct mem_cgroup *mem_cgroup_iter_cond(struct mem_cgroup *root, reclaim->generation = iter->generation; } - /* - * We have finished the whole tree walk or no group has been - * visited because filter told us to skip the root node. - */ - if (!memcg && (prev || (cond && !last_visited))) + if (prev && !memcg) goto out_unlock; } out_unlock: @@ -1767,7 +1854,6 @@ static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg, return total; } -#if MAX_NUMNODES > 1 /** * test_mem_cgroup_node_reclaimable * @memcg: the target memcg @@ -1790,6 +1876,7 @@ static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg, return false; } +#if MAX_NUMNODES > 1 /* * Always updating the nodemask is not very good - even if we have an empty @@ -1857,50 +1944,104 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) return node; } +/* + * Check all nodes whether it contains reclaimable pages or not. + * For quick scan, we make use of scan_nodes. This will allow us to skip + * unused nodes. But scan_nodes is lazily updated and may not cotain + * enough new information. We need to do double check. + */ +static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) +{ + int nid; + + /* + * quick check...making use of scan_node. + * We can skip unused nodes. + */ + if (!nodes_empty(memcg->scan_nodes)) { + for (nid = first_node(memcg->scan_nodes); + nid < MAX_NUMNODES; + nid = next_node(nid, memcg->scan_nodes)) { + + if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) + return true; + } + } + /* + * Check rest of nodes. + */ + for_each_node_state(nid, N_MEMORY) { + if (node_isset(nid, memcg->scan_nodes)) + continue; + if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap)) + return true; + } + return false; +} + #else int mem_cgroup_select_victim_node(struct mem_cgroup *memcg) { return 0; } -#endif - -/* - * A group is eligible for the soft limit reclaim under the given root - * hierarchy if - * a) it is over its soft limit - * b) any parent up the hierarchy is over its soft limit - * - * If the given group doesn't have any children over the limit then it - * doesn't make any sense to iterate its subtree. - */ -enum mem_cgroup_filter_t -mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, - struct mem_cgroup *root) +static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap) { - struct mem_cgroup *parent; - - if (!memcg) - memcg = root_mem_cgroup; - parent = memcg; - - if (res_counter_soft_limit_excess(&memcg->res)) - return VISIT; + return test_mem_cgroup_node_reclaimable(memcg, 0, noswap); +} +#endif - /* - * If any parent up to the root in the hierarchy is over its soft limit - * then we have to obey and reclaim from this group as well. - */ - while ((parent = parent_mem_cgroup(parent))) { - if (res_counter_soft_limit_excess(&parent->res)) - return VISIT; - if (parent == root) +static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, + struct zone *zone, + gfp_t gfp_mask, + unsigned long *total_scanned) +{ + struct mem_cgroup *victim = NULL; + int total = 0; + int loop = 0; + unsigned long excess; + unsigned long nr_scanned; + struct mem_cgroup_reclaim_cookie reclaim = { + .zone = zone, + .priority = 0, + }; + + excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT; + + while (1) { + victim = mem_cgroup_iter(root_memcg, victim, &reclaim); + if (!victim) { + loop++; + if (loop >= 2) { + /* + * If we have not been able to reclaim + * anything, it might because there are + * no reclaimable pages under this hierarchy + */ + if (!total) + break; + /* + * We want to do more targeted reclaim. + * excess >> 2 is not to excessive so as to + * reclaim too much, nor too less that we keep + * coming back to reclaim from this cgroup + */ + if (total >= (excess >> 2) || + (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) + break; + } + continue; + } + if (!mem_cgroup_reclaimable(victim, false)) + continue; + total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false, + zone, &nr_scanned); + *total_scanned += nr_scanned; + if (!res_counter_soft_limit_excess(&root_memcg->res)) break; } - - if (!atomic_read(&memcg->children_in_excess)) - return SKIP_TREE; - return SKIP; + mem_cgroup_iter_break(root_memcg, victim); + return total; } static DEFINE_SPINLOCK(memcg_oom_lock); @@ -2812,7 +2953,9 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, unlock_page_cgroup(pc); /* - * "charge_statistics" updated event counter. + * "charge_statistics" updated event counter. Then, check it. + * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. + * if they exceeds softlimit. */ memcg_check_events(memcg, page); } @@ -4647,6 +4790,98 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg, return ret; } +unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, + gfp_t gfp_mask, + unsigned long *total_scanned) +{ + unsigned long nr_reclaimed = 0; + struct mem_cgroup_per_zone *mz, *next_mz = NULL; + unsigned long reclaimed; + int loop = 0; + struct mem_cgroup_tree_per_zone *mctz; + unsigned long long excess; + unsigned long nr_scanned; + + if (order > 0) + return 0; + + mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone)); + /* + * This loop can run a while, specially if mem_cgroup's continuously + * keep exceeding their soft limit and putting the system under + * pressure + */ + do { + if (next_mz) + mz = next_mz; + else + mz = mem_cgroup_largest_soft_limit_node(mctz); + if (!mz) + break; + + nr_scanned = 0; + reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone, + gfp_mask, &nr_scanned); + nr_reclaimed += reclaimed; + *total_scanned += nr_scanned; + spin_lock(&mctz->lock); + + /* + * If we failed to reclaim anything from this memory cgroup + * it is time to move on to the next cgroup + */ + next_mz = NULL; + if (!reclaimed) { + do { + /* + * Loop until we find yet another one. + * + * By the time we get the soft_limit lock + * again, someone might have aded the + * group back on the RB tree. Iterate to + * make sure we get a different mem. + * mem_cgroup_largest_soft_limit_node returns + * NULL if no other cgroup is present on + * the tree + */ + next_mz = + __mem_cgroup_largest_soft_limit_node(mctz); + if (next_mz == mz) + css_put(&next_mz->memcg->css); + else /* next_mz == NULL or other memcg */ + break; + } while (1); + } + __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); + excess = res_counter_soft_limit_excess(&mz->memcg->res); + /* + * One school of thought says that we should not add + * back the node to the tree if reclaim returns 0. + * But our reclaim could return 0, simply because due + * to priority we are exposing a smaller subset of + * memory to reclaim from. Consider this as a longer + * term TODO. + */ + /* If excess == 0, no tree ops */ + __mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess); + spin_unlock(&mctz->lock); + css_put(&mz->memcg->css); + loop++; + /* + * Could not reclaim anything and there are no more + * mem cgroups to try or we seem to be looping without + * reclaiming anything. + */ + if (!nr_reclaimed && + (next_mz == NULL || + loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) + break; + } while (!nr_reclaimed); + if (next_mz) + css_put(&next_mz->memcg->css); + return nr_reclaimed; +} + /** * mem_cgroup_force_empty_list - clears LRU of a group * @memcg: group to clear @@ -5911,6 +6146,8 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) for (zone = 0; zone < MAX_NR_ZONES; zone++) { mz = &pn->zoneinfo[zone]; lruvec_init(&mz->lruvec); + mz->usage_in_excess = 0; + mz->on_tree = false; mz->memcg = memcg; } memcg->nodeinfo[node] = pn; @@ -5966,6 +6203,7 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg) int node; size_t size = memcg_size(); + mem_cgroup_remove_from_trees(memcg); free_css_id(&mem_cgroup_subsys, &memcg->css); for_each_node(node) @@ -6002,6 +6240,29 @@ struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg) } EXPORT_SYMBOL(parent_mem_cgroup); +static void __init mem_cgroup_soft_limit_tree_init(void) +{ + struct mem_cgroup_tree_per_node *rtpn; + struct mem_cgroup_tree_per_zone *rtpz; + int tmp, node, zone; + + for_each_node(node) { + tmp = node; + if (!node_state(node, N_NORMAL_MEMORY)) + tmp = -1; + rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp); + BUG_ON(!rtpn); + + soft_limit_tree.rb_tree_per_node[node] = rtpn; + + for (zone = 0; zone < MAX_NR_ZONES; zone++) { + rtpz = &rtpn->rb_tree_per_zone[zone]; + rtpz->rb_root = RB_ROOT; + spin_lock_init(&rtpz->lock); + } + } +} + static struct cgroup_subsys_state * __ref mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) { @@ -6031,7 +6292,6 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) mutex_init(&memcg->thresholds_lock); spin_lock_init(&memcg->move_lock); vmpressure_init(&memcg->vmpressure); - spin_lock_init(&memcg->soft_lock); return &memcg->css; @@ -6109,13 +6369,6 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) mem_cgroup_invalidate_reclaim_iterators(memcg); mem_cgroup_reparent_charges(memcg); - if (memcg->soft_contributed) { - while ((memcg = parent_mem_cgroup(memcg))) - atomic_dec(&memcg->children_in_excess); - - if (memcg != root_mem_cgroup && !root_mem_cgroup->use_hierarchy) - atomic_dec(&root_mem_cgroup->children_in_excess); - } mem_cgroup_destroy_all_caches(memcg); vmpressure_cleanup(&memcg->vmpressure); } @@ -6790,6 +7043,7 @@ static int __init mem_cgroup_init(void) { hotcpu_notifier(memcg_cpu_hotplug_callback, 0); enable_swap_cgroup(); + mem_cgroup_soft_limit_tree_init(); memcg_stock_init(); return 0; } diff --git a/mm/vmscan.c b/mm/vmscan.c index 8ed1b775bdc9..beb35778c69f 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -139,23 +139,11 @@ static bool global_reclaim(struct scan_control *sc) { return !sc->target_mem_cgroup; } - -static bool mem_cgroup_should_soft_reclaim(struct scan_control *sc) -{ - struct mem_cgroup *root = sc->target_mem_cgroup; - return !mem_cgroup_disabled() && - mem_cgroup_soft_reclaim_eligible(root, root) != SKIP_TREE; -} #else static bool global_reclaim(struct scan_control *sc) { return true; } - -static bool mem_cgroup_should_soft_reclaim(struct scan_control *sc) -{ - return false; -} #endif unsigned long zone_reclaimable_pages(struct zone *zone) @@ -2176,11 +2164,9 @@ static inline bool should_continue_reclaim(struct zone *zone, } } -static int -__shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim) +static void shrink_zone(struct zone *zone, struct scan_control *sc) { unsigned long nr_reclaimed, nr_scanned; - int groups_scanned = 0; do { struct mem_cgroup *root = sc->target_mem_cgroup; @@ -2188,17 +2174,15 @@ __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim) .zone = zone, .priority = sc->priority, }; - struct mem_cgroup *memcg = NULL; - mem_cgroup_iter_filter filter = (soft_reclaim) ? - mem_cgroup_soft_reclaim_eligible : NULL; + struct mem_cgroup *memcg; nr_reclaimed = sc->nr_reclaimed; nr_scanned = sc->nr_scanned; - while ((memcg = mem_cgroup_iter_cond(root, memcg, &reclaim, filter))) { + memcg = mem_cgroup_iter(root, NULL, &reclaim); + do { struct lruvec *lruvec; - groups_scanned++; lruvec = mem_cgroup_zone_lruvec(zone, memcg); shrink_lruvec(lruvec, sc); @@ -2218,7 +2202,8 @@ __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim) mem_cgroup_iter_break(root, memcg); break; } - } + memcg = mem_cgroup_iter(root, memcg, &reclaim); + } while (memcg); vmpressure(sc->gfp_mask, sc->target_mem_cgroup, sc->nr_scanned - nr_scanned, @@ -2226,37 +2211,6 @@ __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim) } while (should_continue_reclaim(zone, sc->nr_reclaimed - nr_reclaimed, sc->nr_scanned - nr_scanned, sc)); - - return groups_scanned; -} - - -static void shrink_zone(struct zone *zone, struct scan_control *sc) -{ - bool do_soft_reclaim = mem_cgroup_should_soft_reclaim(sc); - unsigned long nr_scanned = sc->nr_scanned; - int scanned_groups; - - scanned_groups = __shrink_zone(zone, sc, do_soft_reclaim); - /* - * memcg iterator might race with other reclaimer or start from - * a incomplete tree walk so the tree walk in __shrink_zone - * might have missed groups that are above the soft limit. Try - * another loop to catch up with others. Do it just once to - * prevent from reclaim latencies when other reclaimers always - * preempt this one. - */ - if (do_soft_reclaim && !scanned_groups) - __shrink_zone(zone, sc, do_soft_reclaim); - - /* - * No group is over the soft limit or those that are do not have - * pages in the zone we are reclaiming so we have to reclaim everybody - */ - if (do_soft_reclaim && (sc->nr_scanned == nr_scanned)) { - __shrink_zone(zone, sc, false); - return; - } } /* Returns true if compaction should go ahead for a high-order request */ @@ -2320,6 +2274,8 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) { struct zoneref *z; struct zone *zone; + unsigned long nr_soft_reclaimed; + unsigned long nr_soft_scanned; bool aborted_reclaim = false; /* @@ -2359,6 +2315,18 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) continue; } } + /* + * This steals pages from memory cgroups over softlimit + * and returns the number of reclaimed pages and + * scanned pages. This works for global memory pressure + * and balancing, not for a memcg's limit. + */ + nr_soft_scanned = 0; + nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone, + sc->order, sc->gfp_mask, + &nr_soft_scanned); + sc->nr_reclaimed += nr_soft_reclaimed; + sc->nr_scanned += nr_soft_scanned; /* need some check for avoid more shrink_zone() */ } @@ -2952,6 +2920,8 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, { int i; int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */ + unsigned long nr_soft_reclaimed; + unsigned long nr_soft_scanned; struct scan_control sc = { .gfp_mask = GFP_KERNEL, .priority = DEF_PRIORITY, @@ -3066,6 +3036,15 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, sc.nr_scanned = 0; + nr_soft_scanned = 0; + /* + * Call soft limit reclaim before calling shrink_zone. + */ + nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone, + order, sc.gfp_mask, + &nr_soft_scanned); + sc.nr_reclaimed += nr_soft_reclaimed; + /* * There should be no need to raise the scanning * priority if enough pages are already being scanned |
