Merge commit 'v2.6.39' into for-2.6.40/core

Since for-2.6.40/core was forked off the 2.6.39 devel tree, we've
had churn in the core area that makes it difficult to handle
patches for eg cfq or blk-throttle. Instead of requiring that they
be based in older versions with bugs that have been fixed later
in the rc cycle, merge in 2.6.39 final.

Also fixes up conflicts in the below files.

Conflicts:
	drivers/block/paride/pcd.c
	drivers/cdrom/viocd.c
	drivers/ide/ide-cd.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 13 insertions, 2 deletions

diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index b6ed61c95856..7c163477fcd8 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -52,8 +52,10 @@ Brief summary of control files.
  tasks                           # attach a task(thread) and show list of threads
  cgroup.procs                    # show list of processes
  cgroup.event_control            # an interface for event_fd()
- memory.usage_in_bytes           # show current memory(RSS+Cache) usage.
- memory.memsw.usage_in_bytes     # show current memory+Swap usage
+ memory.usage_in_bytes           # show current res_counter usage for memory
+                                 (See 5.5 for details)
+ memory.memsw.usage_in_bytes     # show current res_counter usage for memory+Swap
+                                 (See 5.5 for details)
  memory.limit_in_bytes           # set/show limit of memory usage
  memory.memsw.limit_in_bytes     # set/show limit of memory+Swap usage
  memory.failcnt                  # show the number of memory usage hits limits
@@ -453,6 +455,15 @@ memory under it will be reclaimed.
 You can reset failcnt by writing 0 to failcnt file.
 # echo 0 > .../memory.failcnt
 
+5.5 usage_in_bytes
+
+For efficiency, as other kernel components, memory cgroup uses some optimization
+to avoid unnecessary cacheline false sharing. usage_in_bytes is affected by the
+method and doesn't show 'exact' value of memory(and swap) usage, it's an fuzz
+value for efficient access. (Of course, when necessary, it's synchronized.)
+If you want to know more exact memory usage, you should use RSS+CACHE(+SWAP)
+value in memory.stat(see 5.2).
+
 6. Hierarchy support
 
 The memory controller supports a deep hierarchy and hierarchical accounting.