diff options
-rw-r--r-- | block/blk-core.c | 2 | ||||
-rw-r--r-- | block/blk-mq-tag.c | 1 | ||||
-rw-r--r-- | block/blk-mq.c | 4 | ||||
-rw-r--r-- | block/blk-sysfs.c | 1 | ||||
-rw-r--r-- | drivers/block/nbd.c | 36 | ||||
-rw-r--r-- | drivers/block/nvme-core.c | 24 | ||||
-rw-r--r-- | drivers/block/xen-blkfront.c | 3 | ||||
-rw-r--r-- | fs/fs-writeback.c | 35 | ||||
-rw-r--r-- | include/linux/backing-dev-defs.h | 3 | ||||
-rw-r--r-- | include/linux/backing-dev.h | 69 | ||||
-rw-r--r-- | include/linux/memcontrol.h | 8 | ||||
-rw-r--r-- | mm/backing-dev.c | 36 | ||||
-rw-r--r-- | mm/memcontrol.c | 35 | ||||
-rw-r--r-- | mm/page-writeback.c | 54 |
14 files changed, 167 insertions, 144 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 2eb722d48773..18e92a6645e2 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -576,7 +576,7 @@ void blk_cleanup_queue(struct request_queue *q) q->queue_lock = &q->__queue_lock; spin_unlock_irq(lock); - bdi_destroy(&q->backing_dev_info); + bdi_unregister(&q->backing_dev_info); /* @q is and will stay empty, shutdown and put */ blk_put_queue(q); diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index ed96474d75cb..ec2d11915142 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -641,6 +641,7 @@ void blk_mq_free_tags(struct blk_mq_tags *tags) { bt_free(&tags->bitmap_tags); bt_free(&tags->breserved_tags); + free_cpumask_var(tags->cpumask); kfree(tags); } diff --git a/block/blk-mq.c b/block/blk-mq.c index 7785ae96267a..85f014327342 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2296,10 +2296,8 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set) int i; for (i = 0; i < set->nr_hw_queues; i++) { - if (set->tags[i]) { + if (set->tags[i]) blk_mq_free_rq_map(set, set->tags[i], i); - free_cpumask_var(set->tags[i]->cpumask); - } } kfree(set->tags); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 3e44a9da2a13..07b42f5ad797 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -540,6 +540,7 @@ static void blk_release_queue(struct kobject *kobj) struct request_queue *q = container_of(kobj, struct request_queue, kobj); + bdi_exit(&q->backing_dev_info); blkcg_exit_queue(q); if (q->elevator) { diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 293495a75d3d..1b87623381e2 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -60,6 +60,7 @@ struct nbd_device { bool disconnect; /* a disconnect has been requested by user */ struct timer_list timeout_timer; + spinlock_t tasks_lock; struct task_struct *task_recv; struct task_struct *task_send; @@ -140,21 +141,23 @@ static void sock_shutdown(struct nbd_device *nbd) static void nbd_xmit_timeout(unsigned long arg) { struct nbd_device *nbd = (struct nbd_device *)arg; - struct task_struct *task; + unsigned long flags; if (list_empty(&nbd->queue_head)) return; nbd->disconnect = true; - task = READ_ONCE(nbd->task_recv); - if (task) - force_sig(SIGKILL, task); + spin_lock_irqsave(&nbd->tasks_lock, flags); + + if (nbd->task_recv) + force_sig(SIGKILL, nbd->task_recv); - task = READ_ONCE(nbd->task_send); - if (task) + if (nbd->task_send) force_sig(SIGKILL, nbd->task_send); + spin_unlock_irqrestore(&nbd->tasks_lock, flags); + dev_err(nbd_to_dev(nbd), "Connection timed out, killed receiver and sender, shutting down connection\n"); } @@ -403,17 +406,24 @@ static int nbd_thread_recv(struct nbd_device *nbd) { struct request *req; int ret; + unsigned long flags; BUG_ON(nbd->magic != NBD_MAGIC); sk_set_memalloc(nbd->sock->sk); + spin_lock_irqsave(&nbd->tasks_lock, flags); nbd->task_recv = current; + spin_unlock_irqrestore(&nbd->tasks_lock, flags); ret = device_create_file(disk_to_dev(nbd->disk), &pid_attr); if (ret) { dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); + + spin_lock_irqsave(&nbd->tasks_lock, flags); nbd->task_recv = NULL; + spin_unlock_irqrestore(&nbd->tasks_lock, flags); + return ret; } @@ -429,7 +439,9 @@ static int nbd_thread_recv(struct nbd_device *nbd) device_remove_file(disk_to_dev(nbd->disk), &pid_attr); + spin_lock_irqsave(&nbd->tasks_lock, flags); nbd->task_recv = NULL; + spin_unlock_irqrestore(&nbd->tasks_lock, flags); if (signal_pending(current)) { siginfo_t info; @@ -534,8 +546,11 @@ static int nbd_thread_send(void *data) { struct nbd_device *nbd = data; struct request *req; + unsigned long flags; + spin_lock_irqsave(&nbd->tasks_lock, flags); nbd->task_send = current; + spin_unlock_irqrestore(&nbd->tasks_lock, flags); set_user_nice(current, MIN_NICE); while (!kthread_should_stop() || !list_empty(&nbd->waiting_queue)) { @@ -572,7 +587,15 @@ static int nbd_thread_send(void *data) nbd_handle_req(nbd, req); } + spin_lock_irqsave(&nbd->tasks_lock, flags); nbd->task_send = NULL; + spin_unlock_irqrestore(&nbd->tasks_lock, flags); + + /* Clear maybe pending signals */ + if (signal_pending(current)) { + siginfo_t info; + dequeue_signal_lock(current, ¤t->blocked, &info); + } return 0; } @@ -1052,6 +1075,7 @@ static int __init nbd_init(void) nbd_dev[i].magic = NBD_MAGIC; INIT_LIST_HEAD(&nbd_dev[i].waiting_queue); spin_lock_init(&nbd_dev[i].queue_lock); + spin_lock_init(&nbd_dev[i].tasks_lock); INIT_LIST_HEAD(&nbd_dev[i].queue_head); mutex_init(&nbd_dev[i].tx_lock); init_timer(&nbd_dev[i].timeout_timer); diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index 6f04771f1019..ccc0c1f93daa 100644 --- a/drivers/block/nvme-core.c +++ b/drivers/block/nvme-core.c @@ -603,27 +603,31 @@ static void req_completion(struct nvme_queue *nvmeq, void *ctx, struct nvme_iod *iod = ctx; struct request *req = iod_get_private(iod); struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req); - u16 status = le16_to_cpup(&cqe->status) >> 1; + bool requeue = false; + int error = 0; if (unlikely(status)) { if (!(status & NVME_SC_DNR || blk_noretry_request(req)) && (jiffies - req->start_time) < req->timeout) { unsigned long flags; + requeue = true; blk_mq_requeue_request(req); spin_lock_irqsave(req->q->queue_lock, flags); if (!blk_queue_stopped(req->q)) blk_mq_kick_requeue_list(req->q); spin_unlock_irqrestore(req->q->queue_lock, flags); - return; + goto release_iod; } if (req->cmd_type == REQ_TYPE_DRV_PRIV) { if (cmd_rq->ctx == CMD_CTX_CANCELLED) - status = -EINTR; + error = -EINTR; + else + error = status; } else { - status = nvme_error_status(status); + error = nvme_error_status(status); } } @@ -635,8 +639,9 @@ static void req_completion(struct nvme_queue *nvmeq, void *ctx, if (cmd_rq->aborted) dev_warn(nvmeq->dev->dev, "completing aborted command with status:%04x\n", - status); + error); +release_iod: if (iod->nents) { dma_unmap_sg(nvmeq->dev->dev, iod->sg, iod->nents, rq_data_dir(req) ? DMA_TO_DEVICE : DMA_FROM_DEVICE); @@ -649,7 +654,8 @@ static void req_completion(struct nvme_queue *nvmeq, void *ctx, } nvme_free_iod(nvmeq->dev, iod); - blk_mq_complete_request(req, status); + if (likely(!requeue)) + blk_mq_complete_request(req, error); } /* length is in bytes. gfp flags indicates whether we may sleep. */ @@ -1804,7 +1810,7 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio) length = (io.nblocks + 1) << ns->lba_shift; meta_len = (io.nblocks + 1) * ns->ms; - metadata = (void __user *)(unsigned long)io.metadata; + metadata = (void __user *)(uintptr_t)io.metadata; write = io.opcode & 1; if (ns->ext) { @@ -1844,7 +1850,7 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio) c.rw.metadata = cpu_to_le64(meta_dma); status = __nvme_submit_sync_cmd(ns->queue, &c, NULL, - (void __user *)io.addr, length, NULL, 0); + (void __user *)(uintptr_t)io.addr, length, NULL, 0); unmap: if (meta) { if (status == NVME_SC_SUCCESS && !write) { @@ -1886,7 +1892,7 @@ static int nvme_user_cmd(struct nvme_dev *dev, struct nvme_ns *ns, timeout = msecs_to_jiffies(cmd.timeout_ms); status = __nvme_submit_sync_cmd(ns ? ns->queue : dev->admin_q, &c, - NULL, (void __user *)cmd.addr, cmd.data_len, + NULL, (void __user *)(uintptr_t)cmd.addr, cmd.data_len, &cmd.result, timeout); if (status >= 0) { if (put_user(cmd.result, &ucmd->result)) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 611170896b8c..a69c02dadec0 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1956,7 +1956,8 @@ static void blkback_changed(struct xenbus_device *dev, break; /* Missed the backend's Closing state -- fallthrough */ case XenbusStateClosing: - blkfront_closing(info); + if (info) + blkfront_closing(info); break; } } diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 091a36444972..29e4599f6fc1 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -778,19 +778,24 @@ static void bdi_split_work_to_wbs(struct backing_dev_info *bdi, struct wb_writeback_work *base_work, bool skip_if_busy) { - int next_memcg_id = 0; - struct bdi_writeback *wb; - struct wb_iter iter; + struct bdi_writeback *last_wb = NULL; + struct bdi_writeback *wb = list_entry_rcu(&bdi->wb_list, + struct bdi_writeback, bdi_node); might_sleep(); restart: rcu_read_lock(); - bdi_for_each_wb(wb, bdi, &iter, next_memcg_id) { + list_for_each_entry_continue_rcu(wb, &bdi->wb_list, bdi_node) { DEFINE_WB_COMPLETION_ONSTACK(fallback_work_done); struct wb_writeback_work fallback_work; struct wb_writeback_work *work; long nr_pages; + if (last_wb) { + wb_put(last_wb); + last_wb = NULL; + } + /* SYNC_ALL writes out I_DIRTY_TIME too */ if (!wb_has_dirty_io(wb) && (base_work->sync_mode == WB_SYNC_NONE || @@ -819,12 +824,22 @@ restart: wb_queue_work(wb, work); - next_memcg_id = wb->memcg_css->id + 1; + /* + * Pin @wb so that it stays on @bdi->wb_list. This allows + * continuing iteration from @wb after dropping and + * regrabbing rcu read lock. + */ + wb_get(wb); + last_wb = wb; + rcu_read_unlock(); wb_wait_for_completion(bdi, &fallback_work_done); goto restart; } rcu_read_unlock(); + + if (last_wb) + wb_put(last_wb); } #else /* CONFIG_CGROUP_WRITEBACK */ @@ -1857,12 +1872,11 @@ void wakeup_flusher_threads(long nr_pages, enum wb_reason reason) rcu_read_lock(); list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) { struct bdi_writeback *wb; - struct wb_iter iter; if (!bdi_has_dirty_io(bdi)) continue; - bdi_for_each_wb(wb, bdi, &iter, 0) + list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) wb_start_writeback(wb, wb_split_bdi_pages(wb, nr_pages), false, reason); } @@ -1894,11 +1908,10 @@ static void wakeup_dirtytime_writeback(struct work_struct *w) rcu_read_lock(); list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) { struct bdi_writeback *wb; - struct wb_iter iter; - bdi_for_each_wb(wb, bdi, &iter, 0) - if (!list_empty(&bdi->wb.b_dirty_time)) - wb_wakeup(&bdi->wb); + list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) + if (!list_empty(&wb->b_dirty_time)) + wb_wakeup(wb); } rcu_read_unlock(); schedule_delayed_work(&dirtytime_work, dirtytime_expire_interval * HZ); diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index a23209b43842..1b4d69f68c33 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -116,6 +116,8 @@ struct bdi_writeback { struct list_head work_list; struct delayed_work dwork; /* work item used for writeback */ + struct list_head bdi_node; /* anchored at bdi->wb_list */ + #ifdef CONFIG_CGROUP_WRITEBACK struct percpu_ref refcnt; /* used only for !root wb's */ struct fprop_local_percpu memcg_completions; @@ -150,6 +152,7 @@ struct backing_dev_info { atomic_long_t tot_write_bandwidth; struct bdi_writeback wb; /* the root writeback info for this bdi */ + struct list_head wb_list; /* list of all wbs */ #ifdef CONFIG_CGROUP_WRITEBACK struct radix_tree_root cgwb_tree; /* radix tree of active cgroup wbs */ struct rb_root cgwb_congested_tree; /* their congested states */ diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index d5eb4ad1c534..c85f74946a8b 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -19,13 +19,17 @@ #include <linux/slab.h> int __must_check bdi_init(struct backing_dev_info *bdi); -void bdi_destroy(struct backing_dev_info *bdi); +void bdi_exit(struct backing_dev_info *bdi); __printf(3, 4) int bdi_register(struct backing_dev_info *bdi, struct device *parent, const char *fmt, ...); int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev); +void bdi_unregister(struct backing_dev_info *bdi); + int __must_check bdi_setup_and_register(struct backing_dev_info *, char *); +void bdi_destroy(struct backing_dev_info *bdi); + void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, bool range_cyclic, enum wb_reason reason); void wb_start_background_writeback(struct bdi_writeback *wb); @@ -408,61 +412,6 @@ static inline void unlocked_inode_to_wb_end(struct inode *inode, bool locked) rcu_read_unlock(); } -struct wb_iter { - int start_memcg_id; - struct radix_tree_iter tree_iter; - void **slot; -}; - -static inline struct bdi_writeback *__wb_iter_next(struct wb_iter *iter, - struct backing_dev_info *bdi) -{ - struct radix_tree_iter *titer = &iter->tree_iter; - - WARN_ON_ONCE(!rcu_read_lock_held()); - - if (iter->start_memcg_id >= 0) { - iter->slot = radix_tree_iter_init(titer, iter->start_memcg_id); - iter->start_memcg_id = -1; - } else { - iter->slot = radix_tree_next_slot(iter->slot, titer, 0); - } - - if (!iter->slot) - iter->slot = radix_tree_next_chunk(&bdi->cgwb_tree, titer, 0); - if (iter->slot) - return *iter->slot; - return NULL; -} - -static inline struct bdi_writeback *__wb_iter_init(struct wb_iter *iter, - struct backing_dev_info *bdi, - int start_memcg_id) -{ - iter->start_memcg_id = start_memcg_id; - - if (start_memcg_id) - return __wb_iter_next(iter, bdi); - else - return &bdi->wb; -} - -/** - * bdi_for_each_wb - walk all wb's of a bdi in ascending memcg ID order - * @wb_cur: cursor struct bdi_writeback pointer - * @bdi: bdi to walk wb's of - * @iter: pointer to struct wb_iter to be used as iteration buffer - * @start_memcg_id: memcg ID to start iteration from - * - * Iterate @wb_cur through the wb's (bdi_writeback's) of @bdi in ascending - * memcg ID order starting from @start_memcg_id. @iter is struct wb_iter - * to be used as temp storage during iteration. rcu_read_lock() must be - * held throughout iteration. - */ -#define bdi_for_each_wb(wb_cur, bdi, iter, start_memcg_id) \ - for ((wb_cur) = __wb_iter_init(iter, bdi, start_memcg_id); \ - (wb_cur); (wb_cur) = __wb_iter_next(iter, bdi)) - #else /* CONFIG_CGROUP_WRITEBACK */ static inline bool inode_cgwb_enabled(struct inode *inode) @@ -522,14 +471,6 @@ static inline void wb_blkcg_offline(struct blkcg *blkcg) { } -struct wb_iter { - int next_id; -}; - -#define bdi_for_each_wb(wb_cur, bdi, iter, start_blkcg_id) \ - for ((iter)->next_id = (start_blkcg_id); \ - ({ (wb_cur) = !(iter)->next_id++ ? &(bdi)->wb : NULL; }); ) - static inline int inode_congested(struct inode *inode, int cong_bits) { return wb_congested(&inode_to_bdi(inode)->wb, cong_bits); diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 6452ff4c463f..3e3318ddfc0e 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -676,8 +676,9 @@ enum { struct list_head *mem_cgroup_cgwb_list(struct mem_cgroup *memcg); struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb); -void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pavail, - unsigned long *pdirty, unsigned long *pwriteback); +void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, + unsigned long *pheadroom, unsigned long *pdirty, + unsigned long *pwriteback); #else /* CONFIG_CGROUP_WRITEBACK */ @@ -687,7 +688,8 @@ static inline struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb) } static inline void mem_cgroup_wb_stats(struct bdi_writeback *wb, - unsigned long *pavail, + unsigned long *pfilepages, + unsigned long *pheadroom, unsigned long *pdirty, unsigned long *pwriteback) { diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 2df8ddcb0ca0..619984fc07ec 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -480,6 +480,10 @@ static void cgwb_release_workfn(struct work_struct *work) release_work); struct backing_dev_info *bdi = wb->bdi; + spin_lock_irq(&cgwb_lock); + list_del_rcu(&wb->bdi_node); + spin_unlock_irq(&cgwb_lock); + wb_shutdown(wb); css_put(wb->memcg_css); @@ -575,6 +579,7 @@ static int cgwb_create(struct backing_dev_info *bdi, ret = radix_tree_insert(&bdi->cgwb_tree, memcg_css->id, wb); if (!ret) { atomic_inc(&bdi->usage_cnt); + list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list); list_add(&wb->memcg_node, memcg_cgwb_list); list_add(&wb->blkcg_node, blkcg_cgwb_list); css_get(memcg_css); @@ -676,7 +681,7 @@ static int cgwb_bdi_init(struct backing_dev_info *bdi) static void cgwb_bdi_destroy(struct backing_dev_info *bdi) { struct radix_tree_iter iter; - struct bdi_writeback_congested *congested, *congested_n; + struct rb_node *rbn; void **slot; WARN_ON(test_bit(WB_registered, &bdi->wb.state)); @@ -686,9 +691,11 @@ static void cgwb_bdi_destroy(struct backing_dev_info *bdi) radix_tree_for_each_slot(slot, &bdi->cgwb_tree, &iter, 0) cgwb_kill(*slot); - rbtree_postorder_for_each_entry_safe(congested, congested_n, - &bdi->cgwb_congested_tree, rb_node) { - rb_erase(&congested->rb_node, &bdi->cgwb_congested_tree); + while ((rbn = rb_first(&bdi->cgwb_congested_tree))) { + struct bdi_writeback_congested *congested = + rb_entry(rbn, struct bdi_writeback_congested, rb_node); + + rb_erase(rbn, &bdi->cgwb_congested_tree); congested->bdi = NULL; /* mark @congested unlinked */ } @@ -764,15 +771,22 @@ static void cgwb_bdi_destroy(struct backing_dev_info *bdi) { } int bdi_init(struct backing_dev_info *bdi) { + int ret; + bdi->dev = NULL; bdi->min_ratio = 0; bdi->max_ratio = 100; bdi->max_prop_frac = FPROP_FRAC_BASE; INIT_LIST_HEAD(&bdi->bdi_list); + INIT_LIST_HEAD(&bdi->wb_list); init_waitqueue_head(&bdi->wb_waitq); - return cgwb_bdi_init(bdi); + ret = cgwb_bdi_init(bdi); + + list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list); + + return ret; } EXPORT_SYMBOL(bdi_init); @@ -823,7 +837,7 @@ static void bdi_remove_from_list(struct backing_dev_info *bdi) synchronize_rcu_expedited(); } -void bdi_destroy(struct backing_dev_info *bdi) +void bdi_unregister(struct backing_dev_info *bdi) { /* make sure nobody finds us on the bdi_list anymore */ bdi_remove_from_list(bdi); @@ -835,9 +849,19 @@ void bdi_destroy(struct backing_dev_info *bdi) device_unregister(bdi->dev); bdi->dev = NULL; } +} +void bdi_exit(struct backing_dev_info *bdi) +{ + WARN_ON_ONCE(bdi->dev); wb_exit(&bdi->wb); } + +void bdi_destroy(struct backing_dev_info *bdi) +{ + bdi_unregister(bdi); + bdi_exit(bdi); +} EXPORT_SYMBOL(bdi_destroy); /* diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d9b5c817dce8..c57c4423c688 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3741,44 +3741,43 @@ struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb) /** * mem_cgroup_wb_stats - retrieve writeback related stats from its memcg * @wb: bdi_writeback in question - * @pavail: out parameter for number of available pages + * @pfilepages: out parameter for number of file pages + * @pheadroom: out parameter for number of allocatable pages according to memcg * @pdirty: out parameter for number of dirty pages * @pwriteback: out parameter for number of pages under writeback * - * Determine the numbers of available, dirty, and writeback pages in @wb's - * memcg. Dirty and writeback are self-explanatory. Available is a bit - * more involved. + * Determine the numbers of file, headroom, dirty, and writeback pages in + * @wb's memcg. File, dirty and writeback are self-explanatory. Headroom + * is a bit more involved. * - * A memcg's headroom is "min(max, high) - used". The available memory is - * calculated as the lowest headroom of itself and the ancestors plus the - * number of pages already being used for file pages. Note that this - * doesn't consider the actual amount of available memory in the system. - * The caller should further cap *@pavail accordingly. + * A memcg's headroom is "min(max, high) - used". In the hierarchy, the + * headroom is calculated as the lowest headroom of itself and the + * ancestors. Note that this doesn't consider the actual amount of + * available memory in the system. The caller should further cap + * *@pheadroom accordingly. */ -void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pavail, - unsigned long *pdirty, unsigned long *pwriteback) +void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, + unsigned long *pheadroom, unsigned long *pdirty, + unsigned long *pwriteback) { struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); struct mem_cgroup *parent; - unsigned long head_room = PAGE_COUNTER_MAX; - unsigned long file_pages; *pdirty = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_DIRTY); /* this should eventually include NR_UNSTABLE_NFS */ *pwriteback = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_WRITEBACK); + *pfilepages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) | + (1 << LRU_ACTIVE_FILE)); + *pheadroom = PAGE_COUNTER_MAX; - file_pages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) | - (1 << LRU_ACTIVE_FILE)); while ((parent = parent_mem_cgroup(memcg))) { unsigned long ceiling = min(memcg->memory.limit, memcg->high); unsigned long used = page_counter_read(&memcg->memory); - head_room = min(head_room, ceiling - min(ceiling, used)); + *pheadroom = min(*pheadroom, ceiling - min(ceiling, used)); memcg = parent; } - - *pavail = file_pages + head_room; } #else /* CONFIG_CGROUP_WRITEBACK */ diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0a931cdd4f6b..2c90357c34ea 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -145,9 +145,6 @@ struct dirty_throttle_control { unsigned long pos_ratio; }; -#define DTC_INIT_COMMON(__wb) .wb = (__wb), \ - .wb_completions = &(__wb)->completions - /* * Length of period for aging writeout fractions of bdis. This is an * arbitrarily chosen number. The longer the period, the slower fractions will @@ -157,12 +154,16 @@ struct dirty_throttle_control { #ifdef CONFIG_CGROUP_WRITEBACK -#define GDTC_INIT(__wb) .dom = &global_wb_domain, \ - DTC_INIT_COMMON(__wb) +#define GDTC_INIT(__wb) .wb = (__wb), \ + .dom = &global_wb_domain, \ + .wb_completions = &(__wb)->completions + #define GDTC_INIT_NO_WB .dom = &global_wb_domain -#define MDTC_INIT(__wb, __gdtc) .dom = mem_cgroup_wb_domain(__wb), \ - .gdtc = __gdtc, \ - DTC_INIT_COMMON(__wb) + +#define MDTC_INIT(__wb, __gdtc) .wb = (__wb), \ + .dom = mem_cgroup_wb_domain(__wb), \ + .wb_completions = &(__wb)->memcg_completions, \ + .gdtc = __gdtc static bool mdtc_valid(struct dirty_throttle_control *dtc) { @@ -213,7 +214,8 @@ static void wb_min_max_ratio(struct bdi_writeback *wb, #else /* CONFIG_CGROUP_WRITEBACK */ -#define GDTC_INIT(__wb) DTC_INIT_COMMON(__wb) +#define GDTC_INIT(__wb) .wb = (__wb), \ + .wb_completions = &(__wb)->completions #define GDTC_INIT_NO_WB #define MDTC_INIT(__wb, __gdtc) @@ -682,13 +684,19 @@ static unsigned long hard_dirty_limit(struct wb_domain *dom, return max(thresh, dom->dirty_limit); } -/* memory available to a memcg domain is capped by system-wide clean memory */ -static void mdtc_cap_avail(struct dirty_throttle_control *mdtc) +/* + * Memory which can be further allocated to a memcg domain is capped by + * system-wide clean memory excluding the amount being used in the domain. + */ +static void mdtc_calc_avail(struct dirty_throttle_control *mdtc, + unsigned long filepages, unsigned long headroom) { struct dirty_throttle_control *gdtc = mdtc_gdtc(mdtc); - unsigned long clean = gdtc->avail - min(gdtc->avail, gdtc->dirty); + unsigned long clean = filepages - min(filepages, mdtc->dirty); + unsigned long global_clean = gdtc->avail - min(gdtc->avail, gdtc->dirty); + unsigned long other_clean = global_clean - min(global_clean, clean); - mdtc->avail = min(mdtc->avail, clean); + mdtc->avail = filepages + min(headroom, other_clean); } /** @@ -1562,16 +1570,16 @@ static void balance_dirty_pages(struct address_space *mapping, } if (mdtc) { - unsigned long writeback; + unsigned long filepages, headroom, writeback; /* * If @wb belongs to !root memcg, repeat the same * basic calculations for the memcg domain. */ - mem_cgroup_wb_stats(wb, &mdtc->avail, &mdtc->dirty, - &writeback); - mdtc_cap_avail(mdtc); + mem_cgroup_wb_stats(wb, &filepages, &headroom, + &mdtc->dirty, &writeback); mdtc->dirty += writeback; + mdtc_calc_avail(mdtc, filepages, headroom); domain_dirty_limits(mdtc); @@ -1893,10 +1901,11 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb) return true; if (mdtc) { - unsigned long writeback; + unsigned long filepages, headroom, writeback; - mem_cgroup_wb_stats(wb, &mdtc->avail, &mdtc->dirty, &writeback); - mdtc_cap_avail(mdtc); + mem_cgroup_wb_stats(wb, &filepages, &headroom, &mdtc->dirty, + &writeback); + mdtc_calc_avail(mdtc, filepages, headroom); domain_dirty_limits(mdtc); /* ditto, ignore writeback */ if (mdtc->dirty > mdtc->bg_thresh) @@ -1956,7 +1965,6 @@ void laptop_mode_timer_fn(unsigned long data) int nr_pages = global_page_state(NR_FILE_DIRTY) + global_page_state(NR_UNSTABLE_NFS); struct bdi_writeback *wb; - struct wb_iter iter; /* * We want to write everything out, not just down to the dirty @@ -1965,10 +1973,12 @@ void laptop_mode_timer_fn(unsigned long data) if (!bdi_has_dirty_io(&q->backing_dev_info)) return; - bdi_for_each_wb(wb, &q->backing_dev_info, &iter, 0) + rcu_read_lock(); + list_for_each_entry_rcu(wb, &q->backing_dev_info.wb_list, bdi_node) if (wb_has_dirty_io(wb)) wb_start_writeback(wb, nr_pages, true, WB_REASON_LAPTOP_TIMER); + rcu_read_unlock(); } /* |