Merge 'akpm' patch series

* Merge akpm patch series: (122 commits)
  drivers/connector/cn_proc.c: remove unused local
  Documentation/SubmitChecklist: add RCU debug config options
  reiserfs: use hweight_long()
  reiserfs: use proper little-endian bitops
  pnpacpi: register disabled resources
  drivers/rtc/rtc-tegra.c: properly initialize spinlock
  drivers/rtc/rtc-twl.c: check return value of twl_rtc_write_u8() in twl_rtc_set_time()
  drivers/rtc: add support for Qualcomm PMIC8xxx RTC
  drivers/rtc/rtc-s3c.c: support clock gating
  drivers/rtc/rtc-mpc5121.c: add support for RTC on MPC5200
  init: skip calibration delay if previously done
  misc/eeprom: add eeprom access driver for digsy_mtc board
  misc/eeprom: add driver for microwire 93xx46 EEPROMs
  checkpatch.pl: update $logFunctions
  checkpatch: make utf-8 test --strict
  checkpatch.pl: add ability to ignore various messages
  checkpatch: add a "prefer __aligned" check
  checkpatch: validate signature styles and To: and Cc: lines
  checkpatch: add __rcu as a sparse modifier
  checkpatch: suggest using min_t or max_t
  ...

Did this as a merge because of (trivial) conflicts in
 - Documentation/feature-removal-schedule.txt
 - arch/xtensa/include/asm/uaccess.h
that were just easier to fix up in the merge than in the patch series.

1 files changed, 14 insertions, 3 deletions

diff --git a/mm/thrash.c b/mm/thrash.c
index fabf2d0f516..e53f7d02c17 100644
--- a/mm/thrash.c
+++ b/mm/thrash.c
@@ -6,7 +6,7 @@
  * Released under the GPL, see the file COPYING for details.
  *
  * Simple token based thrashing protection, using the algorithm
- * described in:  http://www.cs.wm.edu/~sjiang/token.pdf
+ * described in: http://www.cse.ohio-state.edu/hpcs/WWW/HTML/publications/abs05-1.html
  *
  * Sep 2006, Ashwin Chaugule <ashwin.chaugule@celunite.com>
  * Improved algorithm to pass token:
@@ -30,8 +30,6 @@
 static DEFINE_SPINLOCK(swap_token_lock);
 struct mm_struct *swap_token_mm;
 struct mem_cgroup *swap_token_memcg;
-static unsigned int global_faults;
-static unsigned int last_aging;
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 static struct mem_cgroup *swap_token_memcg_from_mm(struct mm_struct *mm)
@@ -55,6 +53,8 @@ void grab_swap_token(struct mm_struct *mm)
 {
 	int current_interval;
 	unsigned int old_prio = mm->token_priority;
+	static unsigned int global_faults;
+	static unsigned int last_aging;
 
 	global_faults++;
 
@@ -67,6 +67,17 @@ void grab_swap_token(struct mm_struct *mm)
 	if (!swap_token_mm)
 		goto replace_token;
 
+	/*
+	 * Usually, we don't need priority aging because long interval faults
+	 * makes priority decrease quickly. But there is one exception. If the
+	 * token owner task is sleeping, it never make long interval faults.
+	 * Thus, we need a priority aging mechanism instead. The requirements
+	 * of priority aging are
+	 *  1) An aging interval is reasonable enough long. Too short aging
+	 *     interval makes quick swap token lost and decrease performance.
+	 *  2) The swap token owner task have to get priority aging even if
+	 *     it's under sleep.
+	 */
 	if ((global_faults - last_aging) > TOKEN_AGING_INTERVAL) {
 		swap_token_mm->token_priority /= 2;
 		last_aging = global_faults;