Re: memcg: Fix init/Kconfig documentation
From: KAMEZAWA Hiroyuki
Date: Tue Oct 21 2008 - 02:12:17 EST
On Tue, 21 Oct 2008 11:21:18 +0530
Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:
> From: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
> Date: Tue, 21 Oct 2008 11:12:45 +0530
> Subject: [PATCH] memcg: Update Kconfig to remove the struct page overhead statement.
> The memory resource controller no longer has a struct page overhead
> associated with it. The init/Kconfig help has been replaced with
> something more suitable based on the current implementation.
Oh, this is my version..could you merge if this includes something good ?
Fixes menu help text for memcg-allocate-page-cgroup-at-boot.patch.
Signed-off-by: KAMEZAWA hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
init/Kconfig | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
@@ -401,16 +401,20 @@ config CGROUP_MEM_RES_CTLR
depends on CGROUPS && RESOURCE_COUNTERS
- 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 almost all bads.
+ (and lost 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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