Merge branch 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux

* 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: move MIN_WRITEBACK_PAGES to fs-writeback.c
  writeback: balanced_rate cannot exceed write bandwidth
  writeback: do strict bdi dirty_exceeded
  writeback: avoid tiny dirty poll intervals
  writeback: max, min and target dirty pause time
  writeback: dirty ratelimit - think time compensation
  btrfs: fix dirtied pages accounting on sub-page writes
  writeback: fix dirtied pages accounting on redirty
  writeback: fix dirtied pages accounting on sub-page writes
  writeback: charge leaked page dirties to active tasks
  writeback: Include all dirty inodes in background writeback

3 files changed, 16 insertions, 8 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index f044f66018f2..21cd0303af51 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1544,6 +1544,7 @@ struct task_struct {
 	 */
 	int nr_dirtied;
 	int nr_dirtied_pause;
+	unsigned long dirty_paused_when; /* start of a write-and-pause period */
 
 #ifdef CONFIG_LATENCYTOP
 	int latency_record_count;
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 6dff47304971..995b8bf630ac 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -7,6 +7,8 @@
 #include <linux/sched.h>
 #include <linux/fs.h>
 
+DECLARE_PER_CPU(int, dirty_throttle_leaks);
+
 /*
  * The 1/4 region under the global dirty thresh is for smooth dirty throttling:
  *
@@ -23,11 +25,6 @@
 #define DIRTY_SCOPE		8
 #define DIRTY_FULL_SCOPE	(DIRTY_SCOPE / 2)
 
-/*
- * 4MB minimal write chunk size
- */
-#define MIN_WRITEBACK_PAGES	(4096UL >> (PAGE_CACHE_SHIFT - 10))
-
 struct backing_dev_info;
 
 /*
@@ -194,6 +191,8 @@ void writeback_set_ratelimit(void);
 void tag_pages_for_writeback(struct address_space *mapping,
 			     pgoff_t start, pgoff_t end);
 
+void account_page_redirty(struct page *page);
+
 /* pdflush.c */
 extern int nr_pdflush_threads;	/* Global so it can be exported to sysctl
 				   read-only. */
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index 99d1d0decf88..8588a8918023 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -300,12 +300,13 @@ TRACE_EVENT(balance_dirty_pages,
 		 unsigned long dirty_ratelimit,
 		 unsigned long task_ratelimit,
 		 unsigned long dirtied,
+		 unsigned long period,
 		 long pause,
 		 unsigned long start_time),
 
 	TP_ARGS(bdi, thresh, bg_thresh, dirty, bdi_thresh, bdi_dirty,
 		dirty_ratelimit, task_ratelimit,
-		dirtied, pause, start_time),
+		dirtied, period, pause, start_time),
 
 	TP_STRUCT__entry(
 		__array(	 char,	bdi, 32)
@@ -320,6 +321,8 @@ TRACE_EVENT(balance_dirty_pages,
 		__field(unsigned int,	dirtied_pause)
 		__field(unsigned long,	paused)
 		__field(	 long,	pause)
+		__field(unsigned long,	period)
+		__field(	 long,	think)
 	),
 
 	TP_fast_assign(
@@ -336,6 +339,9 @@ TRACE_EVENT(balance_dirty_pages,
 		__entry->task_ratelimit	= KBps(task_ratelimit);
 		__entry->dirtied	= dirtied;
 		__entry->dirtied_pause	= current->nr_dirtied_pause;
+		__entry->think		= current->dirty_paused_when == 0 ? 0 :
+			 (long)(jiffies - current->dirty_paused_when) * 1000/HZ;
+		__entry->period		= period * 1000 / HZ;
 		__entry->pause		= pause * 1000 / HZ;
 		__entry->paused		= (jiffies - start_time) * 1000 / HZ;
 	),
@@ -346,7 +352,7 @@ TRACE_EVENT(balance_dirty_pages,
 		  "bdi_setpoint=%lu bdi_dirty=%lu "
 		  "dirty_ratelimit=%lu task_ratelimit=%lu "
 		  "dirtied=%u dirtied_pause=%u "
-		  "paused=%lu pause=%ld",
+		  "paused=%lu pause=%ld period=%lu think=%ld",
 		  __entry->bdi,
 		  __entry->limit,
 		  __entry->setpoint,
@@ -358,7 +364,9 @@ TRACE_EVENT(balance_dirty_pages,
 		  __entry->dirtied,
 		  __entry->dirtied_pause,
 		  __entry->paused,	/* ms */
-		  __entry->pause	/* ms */
+		  __entry->pause,	/* ms */
+		  __entry->period,	/* ms */
+		  __entry->think	/* ms */
 	  )
 );