From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Mon, 7 Nov 2011 03:02:23 +0000 (-0800)
Subject: Merge branch 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git... 
X-Git-Tag: v3.2-rc1~23
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=208bca0860406d16398145ddd950036a737c3c9d

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

* 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: Add a 'reason' to wb_writeback_work
  writeback: send work item to queue_io, move_expired_inodes
  writeback: trace event balance_dirty_pages
  writeback: trace event bdi_dirty_ratelimit
  writeback: fix ppc compile warnings on do_div(long long, unsigned long)
  writeback: per-bdi background threshold
  writeback: dirty position control - bdi reserve area
  writeback: control dirty pause time
  writeback: limit max dirty pause time
  writeback: IO-less balance_dirty_pages()
  writeback: per task dirty rate limit
  writeback: stabilize bdi->dirty_ratelimit
  writeback: dirty rate control
  writeback: add bg_threshold parameter to __bdi_update_bandwidth()
  writeback: dirty position control
  writeback: account per-bdi accumulated dirtied pages
---

208bca0860406d16398145ddd950036a737c3c9d
diff --cc mm/page-writeback.c
index 793e9874de51,650846b61584..9c31199dae9a
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@@ -260,54 -250,8 +250,10 @@@ static void bdi_writeout_fraction(struc
  				numerator, denominator);
  }
  
- static inline void task_dirties_fraction(struct task_struct *tsk,
- 		long *numerator, long *denominator)
- {
- 	prop_fraction_single(&vm_dirties, &tsk->dirties,
- 				numerator, denominator);
- }
- 
- /*
-  * task_dirty_limit - scale down dirty throttling threshold for one task
-  *
-  * task specific dirty limit:
-  *
-  *   dirty -= (dirty/8) * p_{t}
-  *
-  * To protect light/slow dirtying tasks from heavier/fast ones, we start
-  * throttling individual tasks before reaching the bdi dirty limit.
-  * Relatively low thresholds will be allocated to heavy dirtiers. So when
-  * dirty pages grow large, heavy dirtiers will be throttled first, which will
-  * effectively curb the growth of dirty pages. Light dirtiers with high enough
-  * dirty threshold may never get throttled.
-  */
- #define TASK_LIMIT_FRACTION 8
- static unsigned long task_dirty_limit(struct task_struct *tsk,
- 				       unsigned long bdi_dirty)
- {
- 	long numerator, denominator;
- 	unsigned long dirty = bdi_dirty;
- 	u64 inv = dirty / TASK_LIMIT_FRACTION;
- 
- 	task_dirties_fraction(tsk, &numerator, &denominator);
- 	inv *= numerator;
- 	do_div(inv, denominator);
- 
- 	dirty -= inv;
- 
- 	return max(dirty, bdi_dirty/2);
- }
- 
- /* Minimum limit for any task */
- static unsigned long task_min_dirty_limit(unsigned long bdi_dirty)
- {
- 	return bdi_dirty - bdi_dirty / TASK_LIMIT_FRACTION;
- }
- 
  /*
 - *
 + * bdi_min_ratio keeps the sum of the minimum dirty shares of all
 + * registered backing devices, which, for obvious reasons, can not
 + * exceed 100%.
   */
  static unsigned int bdi_min_ratio;