linux-kernel - Re: [PATCH 3/3] memcgoup: allow memory.failcnt to be reset

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20080311191649.32a2cbae.kamezawa.hiroyu@jp.fujitsu.com>
Date:	Tue, 11 Mar 2008 19:16:49 +0900
From:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
To:	Li Zefan <lizf@...fujitsu.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Balbir Singh <balbir@...ux.vnet.ibm.com>,
	Paul Menage <menage@...gle.com>,
	Pavel Emelianov <xemul@...nvz.org>,
	LKML <linux-kernel@...r.kernel.org>, linux-mm@...ck.org,
	Linux Containers <containers@...ts.osdl.org>
Subject: Re: [PATCH 3/3] memcgoup: allow memory.failcnt to be reset

On Tue, 11 Mar 2008 19:09:02 +0900
Li Zefan <lizf@...fujitsu.com> wrote:

> Allow memory.failcnt to be reset to 0:
> 
>         echo 0 > memory.failcnt
> 
> And '0' is the only valid value.
> 
Can't this be generic resource counter function ?

Thanks,
-Kame


> This is useful when testing or observing the memory resource
> controller. Without this function, one will have to remember
> the previous failcnt to decide whether memory reclaim has
> happened *again*.
> 
> Signed-off-by: Li Zefan <lizf@...fujitsu.com>
> ---
>  Documentation/controllers/memory.txt |    4 +++-
>  mm/memcontrol.c                      |   15 +++++++++++++++
>  2 files changed, 18 insertions(+), 1 deletions(-)
> 
> diff --git a/Documentation/controllers/memory.txt b/Documentation/controllers/memory.txt
> index 866b9cd..28f80e3 100644
> --- a/Documentation/controllers/memory.txt
> +++ b/Documentation/controllers/memory.txt
> @@ -194,7 +194,9 @@ this file after a write to guarantee the value committed by the kernel.
>  4096
>  
>  The memory.failcnt field gives the number of times that the cgroup limit was
> -exceeded.
> +exceeded. It can be reset.
> +
> +# echo 0 > memory.failcnt
>  
>  The memory.stat file gives accounting information. Now, the number of
>  caches, RSS and Active pages/Inactive pages are shown.
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 6145031..fd26dc2 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -883,6 +883,20 @@ static int mem_force_empty_write(struct cgroup *cont, struct cftype *cft,
>  	return ret;
>  }
>  
> +static int mem_failcnt_write(struct cgroup *cont, struct cftype *cft,
> +			     u64 val)
> +{
> +	struct res_counter *counter;
> +
> +	if (val != 0)
> +		return -EINVAL;
> +
> +	counter = &mem_cgroup_from_cont(cont)->res;
> +	res_counter_write_u64(counter, cft->private, 0);
> +
> +	return 0;
> +}
> +
>  static const struct mem_cgroup_stat_desc {
>  	const char *msg;
>  	u64 unit;
> @@ -934,6 +948,7 @@ static struct cftype mem_cgroup_files[] = {
>  	{
>  		.name = "failcnt",
>  		.private = RES_FAILCNT,
> +		.write_u64 = mem_failcnt_write,
>  		.read_u64 = mem_cgroup_read,
>  	},
>  	{
> -- 
> 1.5.4.rc3
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/