diff options
| -rw-r--r-- | mm/memcontrol.c | 170 |
1 files changed, 83 insertions, 87 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index dd845d2..5e7a14d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -660,40 +660,57 @@ static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) return mem; } -/* - * Call callback function against all cgroup under hierarchy tree. - */ -static int mem_cgroup_walk_tree(struct mem_cgroup *root, void *data, - int (*func)(struct mem_cgroup *, void *)) +/* The caller has to guarantee "mem" exists before calling this */ +static struct mem_cgroup *mem_cgroup_start_loop(struct mem_cgroup *mem) { - int found, ret, nextid; + if (mem && css_tryget(&mem->css)) + return mem; + return NULL; +} + +static struct mem_cgroup *mem_cgroup_get_next(struct mem_cgroup *iter, + struct mem_cgroup *root, + bool cond) +{ + int nextid = css_id(&iter->css) + 1; + int found; + int hierarchy_used; struct cgroup_subsys_state *css; - struct mem_cgroup *mem; - if (!root->use_hierarchy) - return (*func)(root, data); + hierarchy_used = iter->use_hierarchy; - nextid = 1; - do { - ret = 0; - mem = NULL; + css_put(&iter->css); + if (!cond || !hierarchy_used) + return NULL; + do { + iter = NULL; rcu_read_lock(); - css = css_get_next(&mem_cgroup_subsys, nextid, &root->css, - &found); + + css = css_get_next(&mem_cgroup_subsys, nextid, + &root->css, &found); if (css && css_tryget(css)) - mem = container_of(css, struct mem_cgroup, css); + iter = container_of(css, struct mem_cgroup, css); rcu_read_unlock(); - - if (mem) { - ret = (*func)(mem, data); - css_put(&mem->css); - } + /* If css is NULL, no more cgroups will be found */ nextid = found + 1; - } while (!ret && css); + } while (css && !iter); - return ret; + return iter; } +/* + * for_eacn_mem_cgroup_tree() for visiting all cgroup under tree. Please + * be careful that "break" loop is not allowed. We have reference count. + * Instead of that modify "cond" to be false and "continue" to exit the loop. + */ +#define for_each_mem_cgroup_tree_cond(iter, root, cond) \ + for (iter = mem_cgroup_start_loop(root);\ + iter != NULL;\ + iter = mem_cgroup_get_next(iter, root, cond)) + +#define for_each_mem_cgroup_tree(iter, root) \ + for_each_mem_cgroup_tree_cond(iter, root, true) + static inline bool mem_cgroup_is_root(struct mem_cgroup *mem) { @@ -1132,13 +1149,6 @@ static bool mem_cgroup_wait_acct_move(struct mem_cgroup *mem) return false; } -static int mem_cgroup_count_children_cb(struct mem_cgroup *mem, void *data) -{ - int *val = data; - (*val)++; - return 0; -} - /** * mem_cgroup_print_oom_info: Called from OOM with tasklist_lock held in read mode. * @memcg: The memory cgroup that went over limit @@ -1213,7 +1223,10 @@ done: static int mem_cgroup_count_children(struct mem_cgroup *mem) { int num = 0; - mem_cgroup_walk_tree(mem, &num, mem_cgroup_count_children_cb); + struct mem_cgroup *iter; + + for_each_mem_cgroup_tree(iter, mem) + num++; return num; } @@ -1362,49 +1375,39 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, return total; } -static int mem_cgroup_oom_lock_cb(struct mem_cgroup *mem, void *data) -{ - int *val = (int *)data; - int x; - /* - * Logically, we can stop scanning immediately when we find - * a memcg is already locked. But condidering unlock ops and - * creation/removal of memcg, scan-all is simple operation. - */ - x = atomic_inc_return(&mem->oom_lock); - *val = max(x, *val); - return 0; -} /* * Check OOM-Killer is already running under our hierarchy. * If someone is running, return false. */ static bool mem_cgroup_oom_lock(struct mem_cgroup *mem) { - int lock_count = 0; + int x, lock_count = 0; + struct mem_cgroup *iter; - mem_cgroup_walk_tree(mem, &lock_count, mem_cgroup_oom_lock_cb); + for_each_mem_cgroup_tree(iter, mem) { + x = atomic_inc_return(&iter->oom_lock); + lock_count = max(x, lock_count); + } if (lock_count == 1) return true; return false; } -static int mem_cgroup_oom_unlock_cb(struct mem_cgroup *mem, void *data) +static int mem_cgroup_oom_unlock(struct mem_cgroup *mem) { + struct mem_cgroup *iter; + /* * When a new child is created while the hierarchy is under oom, * mem_cgroup_oom_lock() may not be called. We have to use * atomic_add_unless() here. */ - atomic_add_unless(&mem->oom_lock, -1, 0); + for_each_mem_cgroup_tree(iter, mem) + atomic_add_unless(&iter->oom_lock, -1, 0); return 0; } -static void mem_cgroup_oom_unlock(struct mem_cgroup *mem) -{ - mem_cgroup_walk_tree(mem, NULL, mem_cgroup_oom_unlock_cb); -} static DEFINE_MUTEX(memcg_oom_mutex); static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); @@ -3207,33 +3210,25 @@ static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, return retval; } -struct mem_cgroup_idx_data { - s64 val; - enum mem_cgroup_stat_index idx; -}; -static int -mem_cgroup_get_idx_stat(struct mem_cgroup *mem, void *data) +static u64 mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem, + enum mem_cgroup_stat_index idx) { - struct mem_cgroup_idx_data *d = data; - d->val += mem_cgroup_read_stat(mem, d->idx); - return 0; -} + struct mem_cgroup *iter; + s64 val = 0; -static void -mem_cgroup_get_recursive_idx_stat(struct mem_cgroup *mem, - enum mem_cgroup_stat_index idx, s64 *val) -{ - struct mem_cgroup_idx_data d; - d.idx = idx; - d.val = 0; - mem_cgroup_walk_tree(mem, &d, mem_cgroup_get_idx_stat); - *val = d.val; + /* each per cpu's value can be minus.Then, use s64 */ + for_each_mem_cgroup_tree(iter, mem) + val += mem_cgroup_read_stat(iter, idx); + + if (val < 0) /* race ? */ + val = 0; + return val; } static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap) { - u64 idx_val, val; + u64 val; if (!mem_cgroup_is_root(mem)) { if (!swap) @@ -3242,16 +3237,12 @@ static inline u64 mem_cgroup_usage(struct mem_cgroup *mem, bool swap) return res_counter_read_u64(&mem->memsw, RES_USAGE); } - mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE, &idx_val); - val = idx_val; - mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS, &idx_val); - val += idx_val; + val = mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_CACHE); + val += mem_cgroup_get_recursive_idx_stat(mem, MEM_CGROUP_STAT_RSS); - if (swap) { - mem_cgroup_get_recursive_idx_stat(mem, - MEM_CGROUP_STAT_SWAPOUT, &idx_val); - val += idx_val; - } + if (swap) + val += mem_cgroup_get_recursive_idx_stat(mem, + MEM_CGROUP_STAT_SWAPOUT); return val << PAGE_SHIFT; } @@ -3459,9 +3450,9 @@ struct { }; -static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data) +static void +mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s) { - struct mcs_total_stat *s = data; s64 val; /* per cpu stat */ @@ -3491,13 +3482,15 @@ static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data) s->stat[MCS_ACTIVE_FILE] += val * PAGE_SIZE; val = mem_cgroup_get_local_zonestat(mem, LRU_UNEVICTABLE); s->stat[MCS_UNEVICTABLE] += val * PAGE_SIZE; - return 0; } static void mem_cgroup_get_total_stat(struct mem_cgroup *mem, struct mcs_total_stat *s) { - mem_cgroup_walk_tree(mem, s, mem_cgroup_get_local_stat); + struct mem_cgroup *iter; + + for_each_mem_cgroup_tree(iter, mem) + mem_cgroup_get_local_stat(iter, s); } static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft, @@ -3674,7 +3667,7 @@ static int compare_thresholds(const void *a, const void *b) return _a->threshold - _b->threshold; } -static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem, void *data) +static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem) { struct mem_cgroup_eventfd_list *ev; @@ -3685,7 +3678,10 @@ static int mem_cgroup_oom_notify_cb(struct mem_cgroup *mem, void *data) static void mem_cgroup_oom_notify(struct mem_cgroup *mem) { - mem_cgroup_walk_tree(mem, NULL, mem_cgroup_oom_notify_cb); + struct mem_cgroup *iter; + + for_each_mem_cgroup_tree(iter, mem) + mem_cgroup_oom_notify_cb(iter); } static int mem_cgroup_usage_register_event(struct cgroup *cgrp, |
