Merge branch 'release' of git://lm-sensors.org/kernel/mhoffman/hwmon-2.6

[pandora-kernel.git] / Documentation / controllers / memory.txt

diff --git a/Documentation/controllers/memory.txt b/Documentation/controllers/memory.txt
index b5bbea9..9b53d58 100644 (file)
--- a/Documentation/controllers/memory.txt
+++ b/Documentation/controllers/memory.txt
@@ -1,4 +1,8 @@
-Memory Controller
+Memory Resource Controller
+
+NOTE: The Memory Resource Controller has been generically been referred
+to as the memory controller in this document. Do not confuse memory controller
+used here with the memory controller that is used in hardware.
 
 Salient features
 
@@ -152,7 +156,7 @@ The memory controller uses the following hierarchy
 
 a. Enable CONFIG_CGROUPS
 b. Enable CONFIG_RESOURCE_COUNTERS
-c. Enable CONFIG_CGROUP_MEM_CONT
+c. Enable CONFIG_CGROUP_MEM_RES_CTLR
 
 1. Prepare the cgroups
 # mkdir -p /cgroups
@@ -164,20 +168,20 @@ c. Enable CONFIG_CGROUP_MEM_CONT
 
 Since now we're in the 0 cgroup,
 We can alter the memory limit:
-# echo -n 4M > /cgroups/0/memory.limit_in_bytes
+# echo 4M > /cgroups/0/memory.limit_in_bytes
 
 NOTE: We can use a suffix (k, K, m, M, g or G) to indicate values in kilo,
 mega or gigabytes.
 
 # cat /cgroups/0/memory.limit_in_bytes
-4194304 Bytes
+4194304
 
 NOTE: The interface has now changed to display the usage in bytes
 instead of pages
 
 We can check the usage:
 # cat /cgroups/0/memory.usage_in_bytes
-1216512 Bytes
+1216512
 
 A successful write to this file does not guarantee a successful set of
 this limit to the value written into the file.  This can be due to a
@@ -185,9 +189,9 @@ number of factors, such as rounding up to page boundaries or the total
 availability of memory on the system.  The user is required to re-read
 this file after a write to guarantee the value committed by the kernel.
 
-# echo -n 1 > memory.limit_in_bytes
+# echo 1 > memory.limit_in_bytes
 # cat memory.limit_in_bytes
-4096 Bytes
+4096
 
 The memory.failcnt field gives the number of times that the cgroup limit was
 exceeded.
@@ -197,7 +201,7 @@ caches, RSS and Active pages/Inactive pages are shown.
 
 The memory.force_empty gives an interface to drop *all* charges by force.
 
-# echo -n 1 > memory.force_empty
+# echo 1 > memory.force_empty
 
 will drop all charges in cgroup. Currently, this is maintained for test.
 
@@ -233,20 +237,12 @@ cgroup might have some charge associated with it, even though all
 tasks have migrated away from it. Such charges are automatically dropped at
 rmdir() if there are no tasks.
 
-4.4 Choosing what to account  -- Page Cache (unmapped) vs RSS (mapped)?
-
-The type of memory accounted by the cgroup can be limited to just
-mapped pages by writing "1" to memory.control_type field
-
-echo -n 1 > memory.control_type
-
 5. TODO
 
 1. Add support for accounting huge pages (as a separate controller)
 2. Make per-cgroup scanner reclaim not-shared pages first
 3. Teach controller to account for shared-pages
-4. Start reclamation when the limit is lowered
-5. Start reclamation in the background when the limit is
+4. Start reclamation in the background when the limit is
    not yet hit but the usage is getting closer
 
 Summary
@@ -262,18 +258,19 @@ References
 3. Emelianov, Pavel. Resource controllers based on process cgroups
    http://lkml.org/lkml/2007/3/6/198
 4. Emelianov, Pavel. RSS controller based on process cgroups (v2)
-   http://lkml.org/lkml/2007/4/9/74
+   http://lkml.org/lkml/2007/4/9/78
 5. Emelianov, Pavel. RSS controller based on process cgroups (v3)
    http://lkml.org/lkml/2007/5/30/244
 6. Menage, Paul. Control Groups v10, http://lwn.net/Articles/236032/
 7. Vaidyanathan, Srinivasan, Control Groups: Pagecache accounting and control
    subsystem (v3), http://lwn.net/Articles/235534/
-8. Singh, Balbir. RSS controller V2 test results (lmbench),
+8. Singh, Balbir. RSS controller v2 test results (lmbench),
    http://lkml.org/lkml/2007/5/17/232
-9. Singh, Balbir. RSS controller V2 AIM9 results
+9. Singh, Balbir. RSS controller v2 AIM9 results
    http://lkml.org/lkml/2007/5/18/1
-10. Singh, Balbir. Memory controller v6 results,
+10. Singh, Balbir. Memory controller v6 test results,
     http://lkml.org/lkml/2007/8/19/36
-11. Singh, Balbir. Memory controller v6, http://lkml.org/lkml/2007/8/17/69
+11. Singh, Balbir. Memory controller introduction (v6),
+    http://lkml.org/lkml/2007/8/17/69
 12. Corbet, Jonathan, Controlling memory use in cgroups,
     http://lwn.net/Articles/243795/