diff options
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 62 |
1 files changed, 59 insertions, 3 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 59ac5d6de478..ffb99b4e7527 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3422,6 +3422,50 @@ int mem_cgroup_shmem_charge_fallback(struct page *page, return ret; } +/* + * At replace page cache, newpage is not under any memcg but it's on + * LRU. So, this function doesn't touch res_counter but handles LRU + * in correct way. Both pages are locked so we cannot race with uncharge. + */ +void mem_cgroup_replace_page_cache(struct page *oldpage, + struct page *newpage) +{ + struct mem_cgroup *memcg; + struct page_cgroup *pc; + struct zone *zone; + enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE; + unsigned long flags; + + if (mem_cgroup_disabled()) + return; + + pc = lookup_page_cgroup(oldpage); + /* fix accounting on old pages */ + lock_page_cgroup(pc); + memcg = pc->mem_cgroup; + mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), -1); + ClearPageCgroupUsed(pc); + unlock_page_cgroup(pc); + + if (PageSwapBacked(oldpage)) + type = MEM_CGROUP_CHARGE_TYPE_SHMEM; + + zone = page_zone(newpage); + pc = lookup_page_cgroup(newpage); + /* + * Even if newpage->mapping was NULL before starting replacement, + * the newpage may be on LRU(or pagevec for LRU) already. We lock + * LRU while we overwrite pc->mem_cgroup. + */ + spin_lock_irqsave(&zone->lru_lock, flags); + if (PageLRU(newpage)) + del_page_from_lru_list(zone, newpage, page_lru(newpage)); + __mem_cgroup_commit_charge(memcg, newpage, 1, pc, type); + if (PageLRU(newpage)) + add_page_to_lru_list(zone, newpage, page_lru(newpage)); + spin_unlock_irqrestore(&zone->lru_lock, flags); +} + #ifdef CONFIG_DEBUG_VM static struct page_cgroup *lookup_page_cgroup_used(struct page *page) { @@ -4514,6 +4558,9 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, */ BUG_ON(!thresholds); + if (!thresholds->primary) + goto unlock; + usage = mem_cgroup_usage(memcg, type == _MEMSWAP); /* Check if a threshold crossed before removing */ @@ -4558,11 +4605,17 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, swap_buffers: /* Swap primary and spare array */ thresholds->spare = thresholds->primary; + /* If all events are unregistered, free the spare array */ + if (!new) { + kfree(thresholds->spare); + thresholds->spare = NULL; + } + rcu_assign_pointer(thresholds->primary, new); /* To be sure that nobody uses thresholds */ synchronize_rcu(); - +unlock: mutex_unlock(&memcg->thresholds_lock); } @@ -4963,9 +5016,9 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) int cpu; enable_swap_cgroup(); parent = NULL; - root_mem_cgroup = mem; if (mem_cgroup_soft_limit_tree_init()) goto free_out; + root_mem_cgroup = mem; for_each_possible_cpu(cpu) { struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); @@ -5004,7 +5057,6 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) return &mem->css; free_out: __mem_cgroup_free(mem); - root_mem_cgroup = NULL; return ERR_PTR(error); } @@ -5244,6 +5296,8 @@ static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, spinlock_t *ptl; split_huge_page_pmd(walk->mm, pmd); + if (pmd_trans_unstable(pmd)) + return 0; pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); for (; addr != end; pte++, addr += PAGE_SIZE) @@ -5405,6 +5459,8 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, spinlock_t *ptl; split_huge_page_pmd(walk->mm, pmd); + if (pmd_trans_unstable(pmd)) + return 0; retry: pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); for (; addr != end; addr += PAGE_SIZE) { |