linux-kernel - Re: [PATCH][-mm] memcg: generic filestat update interface.

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] [day] [month] [year] [list]

Message-ID: <xr93lj6tzmzt.fsf@ninji.mtv.corp.google.com>
Date:	Wed, 22 Sep 2010 10:50:14 -0700
From:	Greg Thelen <gthelen@...gle.com>
To:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
Cc:	"linux-mm\@kvack.org" <linux-mm@...ck.org>,
	"balbir\@linux.vnet.ibm.com" <balbir@...ux.vnet.ibm.com>,
	"nishimura\@mxp.nes.nec.co.jp" <nishimura@....nes.nec.co.jp>,
	"akpm\@linux-foundation.org" <akpm@...ux-foundation.org>,
	"linux-kernel\@vger.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH][-mm] memcg: generic filestat update interface.

KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com> writes:

> based on mmotm and other memory cgroup patches in -mm queue.
> ==
> From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
>
> This patch extracts core logic of mem_cgroup_update_file_mapped() as
> mem_cgroup_update_file_stat() and add a skin.
>
> As a planned future update, memory cgroup has to count dirty pages to implement
> dirty_ratio/limit. And more, the number of dirty pages is required to kick flusher
> thread to start writeback. (Now, no kick.)
>
> This patch is preparation for it and makes other statistics implementation
> clearer. Just a clean up.
>
> Note:
> In previous patch series, I wrote a more complicated patch to make the
> more generic and wanted to avoid using switch(). But now, we found page_mapped()
> check is necessary for updage_file_mapepd().We can't avoid to add some conditions.
> I hope this style is enough easy to read and to maintainance.
>
> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
> ---
>  mm/memcontrol.c |   25 ++++++++++++++++++-------
>  1 file changed, 18 insertions(+), 7 deletions(-)
>
> Index: mmotm-0915/mm/memcontrol.c
> ===================================================================
> --- mmotm-0915.orig/mm/memcontrol.c
> +++ mmotm-0915/mm/memcontrol.c
> @@ -1575,7 +1575,8 @@ bool mem_cgroup_handle_oom(struct mem_cg
>   * small, we check MEM_CGROUP_ON_MOVE percpu value and detect there are
>   * possibility of race condition. If there is, we take a lock.
>   */
> -void mem_cgroup_update_file_mapped(struct page *page, int val)
> +
> +static void mem_cgroup_update_file_stat(struct page *page, int idx, int val)
>  {
>  	struct mem_cgroup *mem;
>  	struct page_cgroup *pc = lookup_page_cgroup(page);
> @@ -1597,13 +1598,18 @@ void mem_cgroup_update_file_mapped(struc
>  		if (!mem || !PageCgroupUsed(pc))
>  			goto out;
>  	}
> -	if (val > 0) {
> -		this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
> -		SetPageCgroupFileMapped(pc);
> -	} else {
> -		this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
> -		if (!page_mapped(page)) /* for race between dec->inc counter */
> +
> +	this_cpu_add(mem->stat->count[idx], val);
> +
> +	switch (idx) {
> +	case MEM_CGROUP_STAT_FILE_MAPPED:
> +		if (val > 0)
> +			SetPageCgroupFileMapped(pc);
> +		else if (!page_mapped(page))
>  			ClearPageCgroupFileMapped(pc);
> +		break;
> +	default:
> +		BUG();
>  	}
>  
>  out:
> @@ -1613,6 +1619,11 @@ out:
>  	return;
>  }
>  
> +void mem_cgroup_update_file_mapped(struct page *page, int val)
> +{
> +	mem_cgroup_update_file_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, val);
> +}
> +
>  /*
>   * size of first charge trial. "32" comes from vmscan.c's magic value.
>   * TODO: maybe necessary to use big numbers in big irons.

Reviewed-by: Greg Thelen <gthelen@...gle.com>
--
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/