Re: [RFC][PATCH 1/11] memcg: fix kconfig menu comment

Randy Dunlap
2008-10-24T04:24:13Z

On Thu, 23 Oct 2008 17:59:46 +0900 KAMEZAWA Hiroyuki wrote:

> Fixes menu help text for memcg-allocate-page-cgroup-at-boot.patch.
>
>
> Signed-off-by: KAMEZAWA hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>
> init/Kconfig | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> Index: mmotm-2.6.27+/init/Kconfig
> ===================================================================
> --- mmotm-2.6.27+.orig/init/Kconfig
> +++ mmotm-2.6.27+/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 memoyr resource controller and you can avoid overheads.

memory

> + (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.

---
~Randy