[PATCH] memcg: uptodate menuconfig help text

From: KAMEZAWA Hiroyuki
Date: Tue Oct 21 2008 - 21:55:37 EST


Now, page_cgroup is allocated at boot and memmap doesn't includes pointer for
page_cgroup.
Fixes menu help text for memcg-allocate-page-cgroup-at-boot.patch.

Reviewed-by: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
Signed-off-by: KAMEZAWA hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>

init/Kconfig | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

Index: linux-2.6/init/Kconfig
===================================================================
--- linux-2.6.orig/init/Kconfig
+++ linux-2.6/init/Kconfig
@@ -401,16 +401,20 @@ config CGROUP_MEM_RES_CTLR
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.

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