diff options
Diffstat (limited to 'mm/backing-dev.c')
| -rw-r--r-- | mm/backing-dev.c | 40 |
1 files changed, 25 insertions, 15 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 08b9aab631ab..8fe3ebd6ac00 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -115,6 +115,7 @@ static int bdi_debug_register(struct backing_dev_info *bdi, const char *name) bdi, &bdi_debug_stats_fops); if (!bdi->debug_stats) { debugfs_remove(bdi->debug_dir); + bdi->debug_dir = NULL; return -ENOMEM; } @@ -383,7 +384,7 @@ static void wb_shutdown(struct bdi_writeback *wb) * the barrier provided by test_and_clear_bit() above. */ smp_wmb(); - clear_bit(WB_shutting_down, &wb->state); + clear_and_wake_up_bit(WB_shutting_down, &wb->state); } static void wb_exit(struct bdi_writeback *wb) @@ -411,6 +412,7 @@ static void wb_exit(struct bdi_writeback *wb) * protected. */ static DEFINE_SPINLOCK(cgwb_lock); +static struct workqueue_struct *cgwb_release_wq; /** * wb_congested_get_create - get or create a wb_congested @@ -521,7 +523,7 @@ static void cgwb_release(struct percpu_ref *refcnt) { struct bdi_writeback *wb = container_of(refcnt, struct bdi_writeback, refcnt); - schedule_work(&wb->release_work); + queue_work(cgwb_release_wq, &wb->release_work); } static void cgwb_kill(struct bdi_writeback *wb) @@ -783,6 +785,21 @@ static void cgwb_bdi_register(struct backing_dev_info *bdi) spin_unlock_irq(&cgwb_lock); } +static int __init cgwb_init(void) +{ + /* + * There can be many concurrent release work items overwhelming + * system_wq. Put them in a separate wq and limit concurrency. + * There's no point in executing many of these in parallel. + */ + cgwb_release_wq = alloc_workqueue("cgwb_release", 0, 1); + if (!cgwb_release_wq) + return -ENOMEM; + + return 0; +} +subsys_initcall(cgwb_init); + #else /* CONFIG_CGROUP_WRITEBACK */ static int cgwb_bdi_init(struct backing_dev_info *bdi) @@ -1020,23 +1037,18 @@ EXPORT_SYMBOL(congestion_wait); /** * wait_iff_congested - Conditionally wait for a backing_dev to become uncongested or a pgdat to complete writes - * @pgdat: A pgdat to check if it is heavily congested * @sync: SYNC or ASYNC IO * @timeout: timeout in jiffies * - * In the event of a congested backing_dev (any backing_dev) and the given - * @pgdat has experienced recent congestion, this waits for up to @timeout - * jiffies for either a BDI to exit congestion of the given @sync queue - * or a write to complete. - * - * In the absence of pgdat congestion, cond_resched() is called to yield - * the processor if necessary but otherwise does not sleep. + * In the event of a congested backing_dev (any backing_dev) this waits + * for up to @timeout jiffies for either a BDI to exit congestion of the + * given @sync queue or a write to complete. * * The return value is 0 if the sleep is for the full timeout. Otherwise, * it is the number of jiffies that were still remaining when the function * returned. return_value == timeout implies the function did not sleep. */ -long wait_iff_congested(struct pglist_data *pgdat, int sync, long timeout) +long wait_iff_congested(int sync, long timeout) { long ret; unsigned long start = jiffies; @@ -1044,12 +1056,10 @@ long wait_iff_congested(struct pglist_data *pgdat, int sync, long timeout) wait_queue_head_t *wqh = &congestion_wqh[sync]; /* - * If there is no congestion, or heavy congestion is not being - * encountered in the current pgdat, yield if necessary instead + * If there is no congestion, yield if necessary instead * of sleeping on the congestion queue */ - if (atomic_read(&nr_wb_congested[sync]) == 0 || - !test_bit(PGDAT_CONGESTED, &pgdat->flags)) { + if (atomic_read(&nr_wb_congested[sync]) == 0) { cond_resched(); /* In case we scheduled, work out time remaining */ |