Date: Wed, 14 Apr 2010 11:11:46 -0700
From: Randy Dunlap <randy.dunlap@oracle.com>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: balbir@linux.vnet.ibm.com, "linux-mm@kvack.org" <linux-mm@kvack.org>,
       "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
       "nishimura@mxp.nes.nec.co.jp" <nishimura@mxp.nes.nec.co.jp>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] memcg: update documentation v7
Message-Id: <20100414111146.c2907cd7.randy.dunlap@oracle.com>
In-Reply-To: <20100414102221.2c540a0d.kamezawa.hiroyu@jp.fujitsu.com>
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> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> ---
>  Documentation/cgroups/memory.txt |  289 ++++++++++++++++++++++++++-------------
>  1 file changed, 197 insertions(+), 92 deletions(-)
> 
> Index: mmotm-temp/Documentation/cgroups/memory.txt
> ===================================================================
> --- mmotm-temp.orig/Documentation/cgroups/memory.txt
> +++ mmotm-temp/Documentation/cgroups/memory.txt
> @@ -1,18 +1,15 @@
>  Memory Resource Controller
>  
>  NOTE: The Memory Resource Controller has been generically been referred
> -to as the memory controller in this document. Do not confuse memory controller
> -used here with the memory controller that is used in hardware.
> +      to as the memory controller in this document. Do not confuse memory
> +      controller used here with the memory controller that is used in hardware.
>  
> -Salient features
> -
> -a. Enable control of Anonymous, Page Cache (mapped and unmapped) and
> -   Swap Cache memory pages.
> -b. The infrastructure allows easy addition of other types of memory to control
> -c. Provides *zero overhead* for non memory controller users
> -d. Provides a double LRU: global memory pressure causes reclaim from the
> -   global LRU; a cgroup on hitting a limit, reclaims from the per
> -   cgroup LRU
> +(For editors)
> +In this document:
> +      When we mention a cgroup (cgroupfs's directory) with memory controller,
> +      we call it "memory cgroup". When you see git-log and source code, you'll
> +      see patch's title and function names tend to use "memcg".
> +      In this document, we avoid to use it.

	                   we avoid using it.

>  
>  Benefits and Purpose of the memory controller

> @@ -501,27 +605,28 @@ It's applicable for root and non-root cg
>  
>  memory.oom_control file is for OOM notification and other controls.
>  
> -Memory controler implements oom notifier using cgroup notification
> -API (See cgroups.txt). It allows to register multiple oom notification
> -delivery and gets notification when oom happens.
> +Memory cgroup implements OOM notifier using cgroup notification
> +API (See cgroups.txt). It allows to register multiple OOM notification
> +delivery and gets notification when OOM happens.
>  
>  To register a notifier, application need:
>   - create an eventfd using eventfd(2)
>   - open memory.oom_control file
> - - write string like "<event_fd> <memory.oom_control>" to cgroup.event_control
> + - write string like "<event_fd> <fd of memory.oom_control>" to
> +   cgroup.event_control
>  
> -Application will be notifier through eventfd when oom happens.
> +Application will be notified through eventfd when OOM happens.
>  OOM notification doesn't work for root cgroup.
>  
> -You can disable oom-killer by writing "1" to memory.oom_control file.
> +You can disable OOM-killer by writing "1" to memory.oom_control file.
>  As.

                                             to memory.oom_control file, as:

>  	#echo 1 > memory.oom_control


BTW:  it would be a lot easier [for reviewing] if you could freeze (or merge) this version
and then apply fixes on top of it with a different (and shorter) patch.

Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>

---
~Randy
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