memcg: update menuconfig help text
page_cgroup is now allocated at boot and memmap doesn't includes pointer
for page_cgroup. Fix the menu help text.
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: KAMEZAWA hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/init/Kconfig b/init/Kconfig
index 44e9208..86b00c5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -401,16 +401,20 @@
depends on CGROUPS && RESOURCE_COUNTERS
select MM_OWNER
help
- Provides a memory resource controller that manages both page cache and
- RSS memory.
+ Provides a memory resource controller that manages both anonymous
+ memory and page cache. (See Documentation/controllers/memory.txt)
Note that setting this option increases fixed memory overhead
- associated with each page of memory in the system by 4/8 bytes
- and also increases cache misses because struct page on many 64bit
- systems will not fit into a single cache line anymore.
+ associated with each page of memory in the system. By this,
+ 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
+ usage tracking struct at boot. Total amount of this is printed out
+ at boot.
Only enable when you're ok with these trade offs and really
- sure you need the memory resource controller.
+ sure you need the memory resource controller. Even when you enable
+ this, you can set "cgroup_disable=memory" at your boot option to
+ disable memory resource controller and you can avoid overheads.
+ (and lose benefits of memory resource contoller)
This config option also selects MM_OWNER config option, which
could in turn add some fork/exit overhead.