From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1165939AbdDYGwk (ORCPT <rfc822;w@1wt.eu>);
        Tue, 25 Apr 2017 02:52:40 -0400
Received: from LGEAMRELO12.lge.com ([156.147.23.52]:56542 "EHLO
        lgeamrelo12.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S981094AbdDYGwc (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 25 Apr 2017 02:52:32 -0400
X-Original-SENDERIP: 156.147.1.151
X-Original-MAILFROM: minchan@kernel.org
X-Original-SENDERIP: 165.244.249.25
X-Original-MAILFROM: minchan@kernel.org
X-Original-SENDERIP: 10.177.223.161
X-Original-MAILFROM: minchan@kernel.org
Date: Tue, 25 Apr 2017 15:51:20 +0900
From: Minchan Kim <minchan@kernel.org>
To: <js1304@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        <linux-kernel@vger.kernel.org>, <kernel-team@lge.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: Re: [PATCH v3 3/4] zram: make deduplication feature optional
Message-ID: <20170425065120.GA6578@bbox>
References: <1492737291-11455-1-git-send-email-iamjoonsoo.kim@lge.com>
 <1492737291-11455-4-git-send-email-iamjoonsoo.kim@lge.com>
MIME-Version: 1.0
In-Reply-To: <1492737291-11455-4-git-send-email-iamjoonsoo.kim@lge.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
X-MIMETrack: Itemize by SMTP Server on LGEKRMHUB02/LGE/LG Group(Release 8.5.3FP6|November
 21, 2013) at 2017/04/25 15:51:22,
        Serialize by Router on LGEKRMHUB02/LGE/LG Group(Release 8.5.3FP6|November
 21, 2013) at 2017/04/25 15:51:22,
        Serialize complete at 2017/04/25 15:51:22
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Fri, Apr 21, 2017 at 10:14:50AM +0900, js1304@gmail.com wrote:
> From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> 
> Benefit of deduplication is dependent on the workload so it's not
> preferable to always enable. Therefore, make it optional in Kconfig
> and device param. Default is 'off'. This option will be beneficial
> for users who use the zram as blockdev and stores build output to it.
> 
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

< snip >

>  
>  static struct attribute *zram_disk_attrs[] = {
>  	&dev_attr_disksize.attr,
> @@ -1169,6 +1227,7 @@ static struct attribute *zram_disk_attrs[] = {
>  	&dev_attr_mem_used_max.attr,
>  	&dev_attr_max_comp_streams.attr,
>  	&dev_attr_comp_algorithm.attr,
> +	&dev_attr_use_dedup.attr,
>  	&dev_attr_io_stat.attr,
>  	&dev_attr_mm_stat.attr,
>  	&dev_attr_debug_stat.attr,
> diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
> index 4b86921..3f7649a 100644
> --- a/drivers/block/zram/zram_drv.h
> +++ b/drivers/block/zram/zram_drv.h
> @@ -134,7 +134,12 @@ struct zram {
>  	 * zram is claimed so open request will be failed
>  	 */
>  	bool claim; /* Protected by bdev->bd_mutex */
> +	bool use_dedup;
>  };
>  
> +static inline bool zram_dedup_enabled(struct zram *zram)
> +{
> +	return zram->use_dedup;

#ifdef CONFIG_ZRAM_DEDUP
        return zram->use_dedup;
#else
        return false;
#endif

Otherwise, looks good to me.