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Diffstat (limited to 'Documentation/controllers/memory.txt')
| -rw-r--r-- | Documentation/controllers/memory.txt | 38 |
1 files changed, 18 insertions, 20 deletions
diff --git a/Documentation/controllers/memory.txt b/Documentation/controllers/memory.txt index b5bbea92a61..866b9cd9a95 100644 --- 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. @@ -233,13 +237,6 @@ 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) @@ -262,18 +259,19 @@ 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/ |