Merge branch 'for-linus' into for-3.1/core

Conflicts:
	block/blk-throttle.c
	block/cfq-iosched.c

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

CREDITS

@@ -518,6 +518,14 @@ N: Zach Brown
 E: zab@zabbo.net
 D: maestro pci sound
 
+M: David Brownell
+D: Kernel engineer, mentor, and friend.  Maintained USB EHCI and
+D: gadget layers, SPI subsystem, GPIO subsystem, and more than a few
+D: device drivers.  His encouragement also helped many engineers get
+D: started working on the Linux kernel.  David passed away in early
+D: 2011, and will be greatly missed.
+W: https://lkml.org/lkml/2011/4/5/36
+
 N: Gary Brubaker
 E: xavyer@ix.netcom.com
 D: USB Serial Empeg Empeg-car Mark I/II Driver

Documentation/ABI/testing/sysfs-class-backlight-driver-adp8870

@@ -0,0 +1,56 @@
+What:		/sys/class/backlight/<backlight>/<ambient light zone>_max
+What:		/sys/class/backlight/<backlight>/l1_daylight_max
+What:		/sys/class/backlight/<backlight>/l2_bright_max
+What:		/sys/class/backlight/<backlight>/l3_office_max
+What:		/sys/class/backlight/<backlight>/l4_indoor_max
+What:		/sys/class/backlight/<backlight>/l5_dark_max
+Date:		Mai 2011
+KernelVersion:	2.6.40
+Contact:	device-drivers-devel@blackfin.uclinux.org
+Description:
+		Control the maximum brightness for <ambient light zone>
+		on this <backlight>. Values are between 0 and 127. This file
+		will also show the brightness level stored for this
+		<ambient light zone>.
+
+What:		/sys/class/backlight/<backlight>/<ambient light zone>_dim
+What:		/sys/class/backlight/<backlight>/l2_bright_dim
+What:		/sys/class/backlight/<backlight>/l3_office_dim
+What:		/sys/class/backlight/<backlight>/l4_indoor_dim
+What:		/sys/class/backlight/<backlight>/l5_dark_dim
+Date:		Mai 2011
+KernelVersion:	2.6.40
+Contact:	device-drivers-devel@blackfin.uclinux.org
+Description:
+		Control the dim brightness for <ambient light zone>
+		on this <backlight>. Values are between 0 and 127, typically
+		set to 0. Full off when the backlight is disabled.
+		This file will also show the dim brightness level stored for
+		this <ambient light zone>.
+
+What:		/sys/class/backlight/<backlight>/ambient_light_level
+Date:		Mai 2011
+KernelVersion:	2.6.40
+Contact:	device-drivers-devel@blackfin.uclinux.org
+Description:
+		Get conversion value of the light sensor.
+		This value is updated every 80 ms (when the light sensor
+		is enabled). Returns integer between 0 (dark) and
+		8000 (max ambient brightness)
+
+What:		/sys/class/backlight/<backlight>/ambient_light_zone
+Date:		Mai 2011
+KernelVersion:	2.6.40
+Contact:	device-drivers-devel@blackfin.uclinux.org
+Description:
+		Get/Set current ambient light zone. Reading returns
+		integer between 1..5 (1 = daylight, 2 = bright, ..., 5 = dark).
+		Writing a value between 1..5 forces the backlight controller
+		to enter the corresponding ambient light zone.
+		Writing 0 returns to normal/automatic ambient light level
+		operation. The ambient light sensing feature on these devices
+		is an extension to the API documented in
+		Documentation/ABI/stable/sysfs-class-backlight.
+		It can be enabled by writing the value stored in
+		/sys/class/backlight/<backlight>/max_brightness to
+		/sys/class/backlight/<backlight>/brightness.

Documentation/accounting/cgroupstats.txt

@@ -21,7 +21,7 @@ information will not be available.
 To extract cgroup statistics a utility very similar to getdelays.c
 has been developed, the sample output of the utility is shown below
 
-~/balbir/cgroupstats # ./getdelays  -C "/cgroup/a"
+~/balbir/cgroupstats # ./getdelays  -C "/sys/fs/cgroup/a"
 sleeping 1, blocked 0, running 1, stopped 0, uninterruptible 0
-~/balbir/cgroupstats # ./getdelays  -C "/cgroup"
+~/balbir/cgroupstats # ./getdelays  -C "/sys/fs/cgroup"
 sleeping 155, blocked 0, running 1, stopped 0, uninterruptible 2

Documentation/cgroups/blkio-controller.txt

@@ -28,16 +28,19 @@ cgroups. Here is what you can do.
 - Enable group scheduling in CFQ
 	CONFIG_CFQ_GROUP_IOSCHED=y
 
-- Compile and boot into kernel and mount IO controller (blkio).
+- Compile and boot into kernel and mount IO controller (blkio); see
+  cgroups.txt, Why are cgroups needed?.
 
-	mount -t cgroup -o blkio none /cgroup
+	mount -t tmpfs cgroup_root /sys/fs/cgroup
+	mkdir /sys/fs/cgroup/blkio
+	mount -t cgroup -o blkio none /sys/fs/cgroup/blkio
 
 - Create two cgroups
-	mkdir -p /cgroup/test1/ /cgroup/test2
+	mkdir -p /sys/fs/cgroup/blkio/test1/ /sys/fs/cgroup/blkio/test2
 
 - Set weights of group test1 and test2
-	echo 1000 > /cgroup/test1/blkio.weight
-	echo 500 > /cgroup/test2/blkio.weight
+	echo 1000 > /sys/fs/cgroup/blkio/test1/blkio.weight
+	echo 500 > /sys/fs/cgroup/blkio/test2/blkio.weight
 
 - Create two same size files (say 512MB each) on same disk (file1, file2) and
   launch two dd threads in different cgroup to read those files.
@@ -46,12 +49,12 @@ cgroups. Here is what you can do.
 	echo 3 > /proc/sys/vm/drop_caches
 
 	dd if=/mnt/sdb/zerofile1 of=/dev/null &
-	echo $! > /cgroup/test1/tasks
-	cat /cgroup/test1/tasks
+	echo $! > /sys/fs/cgroup/blkio/test1/tasks
+	cat /sys/fs/cgroup/blkio/test1/tasks
 
 	dd if=/mnt/sdb/zerofile2 of=/dev/null &
-	echo $! > /cgroup/test2/tasks
-	cat /cgroup/test2/tasks
+	echo $! > /sys/fs/cgroup/blkio/test2/tasks
+	cat /sys/fs/cgroup/blkio/test2/tasks
 
 - At macro level, first dd should finish first. To get more precise data, keep
   on looking at (with the help of script), at blkio.disk_time and
@@ -68,13 +71,13 @@ Throttling/Upper Limit policy
 - Enable throttling in block layer
 	CONFIG_BLK_DEV_THROTTLING=y
 
-- Mount blkio controller
-        mount -t cgroup -o blkio none /cgroup/blkio
+- Mount blkio controller (see cgroups.txt, Why are cgroups needed?)
+        mount -t cgroup -o blkio none /sys/fs/cgroup/blkio
 
 - Specify a bandwidth rate on particular device for root group. The format
   for policy is "<major>:<minor>  <byes_per_second>".
 
-        echo "8:16  1048576" > /cgroup/blkio/blkio.read_bps_device
+        echo "8:16  1048576" > /sys/fs/cgroup/blkio/blkio.read_bps_device
 
   Above will put a limit of 1MB/second on reads happening for root group
   on device having major/minor number 8:16.
@@ -108,7 +111,7 @@ Hierarchical Cgroups
   CFQ and throttling will practically treat all groups at same level.
 
 				pivot
-			     /  |   \  \
+			     /  /   \  \
 			root  test1 test2  test3
 
   Down the line we can implement hierarchical accounting/control support
@@ -149,7 +152,7 @@ Proportional weight policy files
 
 	  Following is the format.
 
-	  #echo dev_maj:dev_minor weight > /path/to/cgroup/blkio.weight_device
+	  # echo dev_maj:dev_minor weight > blkio.weight_device
 	  Configure weight=300 on /dev/sdb (8:16) in this cgroup
 	  # echo 8:16 300 > blkio.weight_device
 	  # cat blkio.weight_device

Documentation/cgroups/cgroups.txt

@@ -138,11 +138,11 @@ With the ability to classify tasks differently for different resources
 the admin can easily set up a script which receives exec notifications
 and depending on who is launching the browser he can
 
-       # echo browser_pid > /mnt/<restype>/<userclass>/tasks
+    # echo browser_pid > /sys/fs/cgroup/<restype>/<userclass>/tasks
 
 With only a single hierarchy, he now would potentially have to create
 a separate cgroup for every browser launched and associate it with
-approp network and other resource class.  This may lead to
+appropriate network and other resource class.  This may lead to
 proliferation of such cgroups.
 
 Also lets say that the administrator would like to give enhanced network
@@ -153,9 +153,9 @@ apps enhanced CPU power,
 With ability to write pids directly to resource classes, it's just a
 matter of :
 
-       # echo pid > /mnt/network/<new_class>/tasks
+       # echo pid > /sys/fs/cgroup/network/<new_class>/tasks
        (after some time)
-       # echo pid > /mnt/network/<orig_class>/tasks
+       # echo pid > /sys/fs/cgroup/network/<orig_class>/tasks
 
 Without this ability, he would have to split the cgroup into
 multiple separate ones and then associate the new cgroups with the
@@ -310,21 +310,24 @@ subsystem, this is the case for the cpuset.
 To start a new job that is to be contained within a cgroup, using
 the "cpuset" cgroup subsystem, the steps are something like:
 
- 1) mkdir /dev/cgroup
- 2) mount -t cgroup -ocpuset cpuset /dev/cgroup
- 3) Create the new cgroup by doing mkdir's and write's (or echo's) in
-    the /dev/cgroup virtual file system.
- 4) Start a task that will be the "founding father" of the new job.
- 5) Attach that task to the new cgroup by writing its pid to the
-    /dev/cgroup tasks file for that cgroup.
- 6) fork, exec or clone the job tasks from this founding father task.
+ 1) mount -t tmpfs cgroup_root /sys/fs/cgroup
+ 2) mkdir /sys/fs/cgroup/cpuset
+ 3) mount -t cgroup -ocpuset cpuset /sys/fs/cgroup/cpuset
+ 4) Create the new cgroup by doing mkdir's and write's (or echo's) in
+    the /sys/fs/cgroup virtual file system.
+ 5) Start a task that will be the "founding father" of the new job.
+ 6) Attach that task to the new cgroup by writing its pid to the
+    /sys/fs/cgroup/cpuset/tasks file for that cgroup.
+ 7) fork, exec or clone the job tasks from this founding father task.
 
 For example, the following sequence of commands will setup a cgroup
 named "Charlie", containing just CPUs 2 and 3, and Memory Node 1,
 and then start a subshell 'sh' in that cgroup:
 
-  mount -t cgroup cpuset -ocpuset /dev/cgroup
-  cd /dev/cgroup
+  mount -t tmpfs cgroup_root /sys/fs/cgroup
+  mkdir /sys/fs/cgroup/cpuset
+  mount -t cgroup cpuset -ocpuset /sys/fs/cgroup/cpuset
+  cd /sys/fs/cgroup/cpuset
   mkdir Charlie
   cd Charlie
   /bin/echo 2-3 > cpuset.cpus
@@ -345,7 +348,7 @@ Creating, modifying, using the cgroups can be done through the cgroup
 virtual filesystem.
 
 To mount a cgroup hierarchy with all available subsystems, type:
-# mount -t cgroup xxx /dev/cgroup
+# mount -t cgroup xxx /sys/fs/cgroup
 
 The "xxx" is not interpreted by the cgroup code, but will appear in
 /proc/mounts so may be any useful identifying string that you like.
@@ -354,23 +357,32 @@ Note: Some subsystems do not work without some user input first.  For instance,
 if cpusets are enabled the user will have to populate the cpus and mems files
 for each new cgroup created before that group can be used.
 
+As explained in section `1.2 Why are cgroups needed?' you should create
+different hierarchies of cgroups for each single resource or group of
+resources you want to control. Therefore, you should mount a tmpfs on
+/sys/fs/cgroup and create directories for each cgroup resource or resource
+group.
+
+# mount -t tmpfs cgroup_root /sys/fs/cgroup
+# mkdir /sys/fs/cgroup/rg1
+
 To mount a cgroup hierarchy with just the cpuset and memory
 subsystems, type:
-# mount -t cgroup -o cpuset,memory hier1 /dev/cgroup
+# mount -t cgroup -o cpuset,memory hier1 /sys/fs/cgroup/rg1
 
 To change the set of subsystems bound to a mounted hierarchy, just
 remount with different options:
-# mount -o remount,cpuset,blkio hier1 /dev/cgroup
+# mount -o remount,cpuset,blkio hier1 /sys/fs/cgroup/rg1
 
 Now memory is removed from the hierarchy and blkio is added.
 
 Note this will add blkio to the hierarchy but won't remove memory or
 cpuset, because the new options are appended to the old ones:
-# mount -o remount,blkio /dev/cgroup
+# mount -o remount,blkio /sys/fs/cgroup/rg1
 
 To Specify a hierarchy's release_agent:
 # mount -t cgroup -o cpuset,release_agent="/sbin/cpuset_release_agent" \
-  xxx /dev/cgroup
+  xxx /sys/fs/cgroup/rg1
 
 Note that specifying 'release_agent' more than once will return failure.
 
@@ -379,17 +391,17 @@ when the hierarchy consists of a single (root) cgroup. Supporting
 the ability to arbitrarily bind/unbind subsystems from an existing
 cgroup hierarchy is intended to be implemented in the future.
 
-Then under /dev/cgroup you can find a tree that corresponds to the
-tree of the cgroups in the system. For instance, /dev/cgroup
+Then under /sys/fs/cgroup/rg1 you can find a tree that corresponds to the
+tree of the cgroups in the system. For instance, /sys/fs/cgroup/rg1
 is the cgroup that holds the whole system.
 
 If you want to change the value of release_agent:
-# echo "/sbin/new_release_agent" > /dev/cgroup/release_agent
+# echo "/sbin/new_release_agent" > /sys/fs/cgroup/rg1/release_agent
 
 It can also be changed via remount.
 
-If you want to create a new cgroup under /dev/cgroup:
-# cd /dev/cgroup
+If you want to create a new cgroup under /sys/fs/cgroup/rg1:
+# cd /sys/fs/cgroup/rg1
 # mkdir my_cgroup
 
 Now you want to do something with this cgroup.

Documentation/cgroups/cpuacct.txt

@@ -10,26 +10,25 @@ directly present in its group.
 
 Accounting groups can be created by first mounting the cgroup filesystem.
 
-# mkdir /cgroups
-# mount -t cgroup -ocpuacct none /cgroups
-
-With the above step, the initial or the parent accounting group
-becomes visible at /cgroups. At bootup, this group includes all the
-tasks in the system. /cgroups/tasks lists the tasks in this cgroup.
-/cgroups/cpuacct.usage gives the CPU time (in nanoseconds) obtained by
-this group which is essentially the CPU time obtained by all the tasks
+# mount -t cgroup -ocpuacct none /sys/fs/cgroup
+
+With the above step, the initial or the parent accounting group becomes
+visible at /sys/fs/cgroup. At bootup, this group includes all the tasks in
+the system. /sys/fs/cgroup/tasks lists the tasks in this cgroup.
+/sys/fs/cgroup/cpuacct.usage gives the CPU time (in nanoseconds) obtained
+by this group which is essentially the CPU time obtained by all the tasks
 in the system.
 
-New accounting groups can be created under the parent group /cgroups.
+New accounting groups can be created under the parent group /sys/fs/cgroup.
 
-# cd /cgroups
+# cd /sys/fs/cgroup
 # mkdir g1
 # echo $$ > g1
 
 The above steps create a new group g1 and move the current shell
 process (bash) into it. CPU time consumed by this bash and its children
 can be obtained from g1/cpuacct.usage and the same is accumulated in
-/cgroups/cpuacct.usage also.
+/sys/fs/cgroup/cpuacct.usage also.
 
 cpuacct.stat file lists a few statistics which further divide the
 CPU time obtained by the cgroup into user and system times. Currently

Documentation/cgroups/cpusets.txt

@@ -661,21 +661,21 @@ than stress the kernel.
 
 To start a new job that is to be contained within a cpuset, the steps are:
 
- 1) mkdir /dev/cpuset
- 2) mount -t cgroup -ocpuset cpuset /dev/cpuset
+ 1) mkdir /sys/fs/cgroup/cpuset
+ 2) mount -t cgroup -ocpuset cpuset /sys/fs/cgroup/cpuset
  3) Create the new cpuset by doing mkdir's and write's (or echo's) in
-    the /dev/cpuset virtual file system.
+    the /sys/fs/cgroup/cpuset virtual file system.
  4) Start a task that will be the "founding father" of the new job.
  5) Attach that task to the new cpuset by writing its pid to the
-    /dev/cpuset tasks file for that cpuset.
+    /sys/fs/cgroup/cpuset tasks file for that cpuset.
  6) fork, exec or clone the job tasks from this founding father task.
 
 For example, the following sequence of commands will setup a cpuset
 named "Charlie", containing just CPUs 2 and 3, and Memory Node 1,
 and then start a subshell 'sh' in that cpuset:
 
-  mount -t cgroup -ocpuset cpuset /dev/cpuset
-  cd /dev/cpuset
+  mount -t cgroup -ocpuset cpuset /sys/fs/cgroup/cpuset
+  cd /sys/fs/cgroup/cpuset
   mkdir Charlie
   cd Charlie
   /bin/echo 2-3 > cpuset.cpus
@@ -710,14 +710,14 @@ Creating, modifying, using the cpusets can be done through the cpuset
 virtual filesystem.
 
 To mount it, type:
-# mount -t cgroup -o cpuset cpuset /dev/cpuset
+# mount -t cgroup -o cpuset cpuset /sys/fs/cgroup/cpuset
 
-Then under /dev/cpuset you can find a tree that corresponds to the
-tree of the cpusets in the system. For instance, /dev/cpuset
+Then under /sys/fs/cgroup/cpuset you can find a tree that corresponds to the
+tree of the cpusets in the system. For instance, /sys/fs/cgroup/cpuset
 is the cpuset that holds the whole system.
 
-If you want to create a new cpuset under /dev/cpuset:
-# cd /dev/cpuset
+If you want to create a new cpuset under /sys/fs/cgroup/cpuset:
+# cd /sys/fs/cgroup/cpuset
 # mkdir my_cpuset
 
 Now you want to do something with this cpuset.
@@ -765,12 +765,12 @@ wrapper around the cgroup filesystem.
 
 The command
 
-mount -t cpuset X /dev/cpuset
+mount -t cpuset X /sys/fs/cgroup/cpuset
 
 is equivalent to
 
-mount -t cgroup -ocpuset,noprefix X /dev/cpuset
-echo "/sbin/cpuset_release_agent" > /dev/cpuset/release_agent
+mount -t cgroup -ocpuset,noprefix X /sys/fs/cgroup/cpuset
+echo "/sbin/cpuset_release_agent" > /sys/fs/cgroup/cpuset/release_agent
 
 2.2 Adding/removing cpus
 ------------------------