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Commit 2324c5dd authored by Li Zefan's avatar Li Zefan Committed by Linus Torvalds
Browse files

memcgroup: fix and update documentation 



- remove trailing " Bytes"s in the demonstration
- remove section 4.4 (feature control_type has been removed)
- fix reference section

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: default avatarBalbir Singh <balbir@in.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent bc231d2a

Documentation/controllers/memory.txt

+9 −15
Original line number Original line Diff line number Diff line
@@ -170,14 +170,14 @@ NOTE: We can use a suffix (k, K, m, M, g or G) to indicate values in kilo, 
mega or gigabytes.

mega or gigabytes.





# cat /cgroups/0/memory.limit_in_bytes

# cat /cgroups/0/memory.limit_in_bytes

4194304 Bytes

4194304





NOTE: The interface has now changed to display the usage in bytes

NOTE: The interface has now changed to display the usage in bytes

instead of pages

instead of pages





We can check the usage:

We can check the usage:

# cat /cgroups/0/memory.usage_in_bytes

# cat /cgroups/0/memory.usage_in_bytes

1216512 Bytes

1216512





A successful write to this file does not guarantee a successful set of

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

this limit to the value written into the file.  This can be due to a
@@ -187,7 +187,7 @@ this file after a write to guarantee the value committed by the kernel. 




# echo -n 1 > memory.limit_in_bytes

# echo -n 1 > memory.limit_in_bytes

# cat 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

The memory.failcnt field gives the number of times that the cgroup limit was

exceeded.

exceeded.
@@ -233,13 +233,6 @@ cgroup might have some charge associated with it, even though all 
tasks have migrated away from it. Such charges are automatically dropped at

tasks have migrated away from it. Such charges are automatically dropped at

rmdir() if there are no tasks.

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

5. TODO





1. Add support for accounting huge pages (as a separate controller)

1. Add support for accounting huge pages (as a separate controller)
@@ -262,18 +255,19 @@ References 
3. Emelianov, Pavel. Resource controllers based on process cgroups

3. Emelianov, Pavel. Resource controllers based on process cgroups

   http://lkml.org/lkml/2007/3/6/198

   http://lkml.org/lkml/2007/3/6/198

4. Emelianov, Pavel. RSS controller based on process cgroups (v2)

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)

5. Emelianov, Pavel. RSS controller based on process cgroups (v3)

   http://lkml.org/lkml/2007/5/30/244

   http://lkml.org/lkml/2007/5/30/244

6. Menage, Paul. Control Groups v10, http://lwn.net/Articles/236032/

6. Menage, Paul. Control Groups v10, http://lwn.net/Articles/236032/

7. Vaidyanathan, Srinivasan, Control Groups: Pagecache accounting and control

7. Vaidyanathan, Srinivasan, Control Groups: Pagecache accounting and control

   subsystem (v3), http://lwn.net/Articles/235534/

   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

   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

   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

    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,

12. Corbet, Jonathan, Controlling memory use in cgroups,

    http://lwn.net/Articles/243795/
 
    http://lwn.net/Articles/243795/