"BdiDirtyThresh: %10lu kB\n"
"DirtyThresh: %10lu kB\n"
"BackgroundThresh: %10lu kB\n"
+ "BdiDirtied: %10lu kB\n"
"BdiWritten: %10lu kB\n"
"BdiWriteBandwidth: %10lu kBps\n"
"b_dirty: %10lu\n"
K(bdi_thresh),
K(dirty_thresh),
K(background_thresh),
+ (unsigned long) K(bdi_stat(bdi, BDI_DIRTIED)),
(unsigned long) K(bdi_stat(bdi, BDI_WRITTEN)),
(unsigned long) K(bdi->write_bandwidth),
nr_dirty,
if (bdi->wb.task) {
trace_writeback_wake_thread(bdi);
wake_up_process(bdi->wb.task);
- } else {
+ } else if (bdi->dev) {
/*
* When bdi tasks are inactive for long time, they are killed.
* In this case we have to wake-up the forker thread which
* the bdi from the thread. Hopefully 1024 is
* large enough for efficient IO.
*/
- writeback_inodes_wb(&bdi->wb, 1024);
+ writeback_inodes_wb(&bdi->wb, 1024,
+ WB_REASON_FORKER_THREAD);
} else {
/*
* The spinlock makes sure we do not lose
*/
static void bdi_wb_shutdown(struct backing_dev_info *bdi)
{
+ struct task_struct *task;
+
if (!bdi_cap_writeback_dirty(bdi))
return;
* unfreeze of the thread before calling kthread_stop(), otherwise
* it would never exet if it is currently stuck in the refrigerator.
*/
- if (bdi->wb.task) {
- thaw_process(bdi->wb.task);
- kthread_stop(bdi->wb.task);
+ spin_lock_bh(&bdi->wb_lock);
+ task = bdi->wb.task;
+ bdi->wb.task = NULL;
+ spin_unlock_bh(&bdi->wb_lock);
+
+ if (task) {
+ thaw_process(task);
+ kthread_stop(task);
}
}
void bdi_unregister(struct backing_dev_info *bdi)
{
- if (bdi->dev) {
+ struct device *dev = bdi->dev;
+
+ if (dev) {
bdi_set_min_ratio(bdi, 0);
trace_writeback_bdi_unregister(bdi);
bdi_prune_sb(bdi);
if (!bdi_cap_flush_forker(bdi))
bdi_wb_shutdown(bdi);
bdi_debug_unregister(bdi);
- device_unregister(bdi->dev);
+
+ spin_lock_bh(&bdi->wb_lock);
bdi->dev = NULL;
+ spin_unlock_bh(&bdi->wb_lock);
+
+ device_unregister(dev);
}
}
EXPORT_SYMBOL(bdi_unregister);
bdi->bw_time_stamp = jiffies;
bdi->written_stamp = 0;
+ bdi->balanced_dirty_ratelimit = INIT_BW;
+ bdi->dirty_ratelimit = INIT_BW;
bdi->write_bandwidth = INIT_BW;
bdi->avg_write_bandwidth = INIT_BW;
bdi_unregister(bdi);
+ /*
+ * If bdi_unregister() had already been called earlier, the
+ * wakeup_timer could still be armed because bdi_prune_sb()
+ * can race with the bdi_wakeup_thread_delayed() calls from
+ * __mark_inode_dirty().
+ */
+ del_timer_sync(&bdi->wb.wakeup_timer);
+
for (i = 0; i < NR_BDI_STAT_ITEMS; i++)
percpu_counter_destroy(&bdi->bdi_stat[i]);
* jiffies for either a BDI to exit congestion of the given @sync queue
* or a write to complete.
*
- * In the absence of zone congestion, cond_resched() is called to yield
- * the processor if necessary but otherwise does not sleep.
+ * In the absence of zone congestion, a short sleep or a cond_resched is
+ * performed to yield the processor and to allow other subsystems to make
+ * a forward progress.
*
* 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
*/
if (atomic_read(&nr_bdi_congested[sync]) == 0 ||
!zone_is_reclaim_congested(zone)) {
- cond_resched();
+
+ /*
+ * Memory allocation/reclaim might be called from a WQ
+ * context and the current implementation of the WQ
+ * concurrency control doesn't recognize that a particular
+ * WQ is congested if the worker thread is looping without
+ * ever sleeping. Therefore we have to do a short sleep
+ * here rather than calling cond_resched().
+ */
+ if (current->flags & PF_WQ_WORKER)
+ schedule_timeout_uninterruptible(1);
+ else
+ cond_resched();
/* In case we scheduled, work out time remaining */
ret = timeout - (jiffies - start);