From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=k9B+=NF=vger.kernel.org=linux-kernel-owner@kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
X-Spam-Level: 
X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham
	autolearn_force=no version=3.4.0
Received: from mail.kernel.org (mail.kernel.org [198.145.29.99])
	by smtp.lore.kernel.org (Postfix) with ESMTP id 6BE33C46475
	for <linux-kernel@archiver.kernel.org>; Thu, 25 Oct 2018 06:10:19 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by mail.kernel.org (Postfix) with ESMTP id 3649B20838
	for <linux-kernel@archiver.kernel.org>; Thu, 25 Oct 2018 06:10:19 +0000 (UTC)
DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3649B20838
Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com
Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1727475AbeJYOlb (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Thu, 25 Oct 2018 10:41:31 -0400
Received: from szxga05-in.huawei.com ([45.249.212.191]:13693 "EHLO huawei.com"
        rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP
        id S1727090AbeJYOlb (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Thu, 25 Oct 2018 10:41:31 -0400
Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.58])
        by Forcepoint Email with ESMTP id BF4F2A0441548;
        Thu, 25 Oct 2018 14:10:09 +0800 (CST)
Received: from [127.0.0.1] (10.134.22.195) by DGGEMS401-HUB.china.huawei.com
 (10.3.19.201) with Microsoft SMTP Server id 14.3.408.0; Thu, 25 Oct 2018
 14:10:04 +0800
Subject: Re: [PATCH 3/3] f2fs: export migration_granularity sysfs entry
To:     Yunlong Song <yunlong.song@huawei.com>, <jaegeuk@kernel.org>
CC:     <linux-f2fs-devel@lists.sourceforge.net>,
        <linux-kernel@vger.kernel.org>, <chao@kernel.org>
References: <20181024103728.9870-1-yuchao0@huawei.com>
 <20181024103728.9870-3-yuchao0@huawei.com>
 <a85b83ee-affb-138b-f804-0590eb2cd3be@huawei.com>
From:   Chao Yu <yuchao0@huawei.com>
Message-ID: <d3931432-2add-1c46-9eb4-8b88ac903c67@huawei.com>
Date:   Thu, 25 Oct 2018 14:10:03 +0800
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101
 Thunderbird/52.9.1
MIME-Version: 1.0
In-Reply-To: <a85b83ee-affb-138b-f804-0590eb2cd3be@huawei.com>
Content-Type: text/plain; charset="utf-8"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-Originating-IP: [10.134.22.195]
X-CFilter-Loop: Reflected
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 2018/10/25 11:01, Yunlong Song wrote:
> 
> 
> On 2018/10/24 18:37, Chao Yu wrote:
>> Add one sysfs entry to control migration granularity of GC in large
>> section f2fs, it can be tuned to mitigate heavy overhead of migrating
>> huge number of blocks in large section.
>>
>> Signed-off-by: Chao Yu <yuchao0@huawei.com>
>> ---
>>   Documentation/ABI/testing/sysfs-fs-f2fs | 9 +++++++++
>>   fs/f2fs/sysfs.c                         | 7 +++++++
>>   2 files changed, 16 insertions(+)
>>
>> diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
>> index 3ac41774ad3c..a7ce33199457 100644
>> --- a/Documentation/ABI/testing/sysfs-fs-f2fs
>> +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
>> @@ -92,6 +92,15 @@ Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
>>   Description:
>>   		 Controls the number of trials to find a victim segment.
>>   
>> +What:		/sys/fs/f2fs/<disk>/migration_granularity
>> +Date:		October 2018
>> +Contact:	"Chao Yu" <yuchao0@huawei.com>
>> +Description:
>> +		 Controls migration granularity of garbage collection on large
>> +		 section, it can let GC move partial segment{s} of one section
>> +		 in one GC cycle, so that dispersing heavy overhead GC to
>> +		 multiple lightweight one.
>> +
>>   What:		/sys/fs/f2fs/<disk>/dir_level
>>   Date:		March 2014
>>   Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
>> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
>> index 240e4881279e..b393fda6d6dc 100644
>> --- a/fs/f2fs/sysfs.c
>> +++ b/fs/f2fs/sysfs.c
>> @@ -246,6 +246,11 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
>>   		return count;
>>   	}
>>   
>> +	if (!strcmp(a->attr.name, "discard_granularity")) {
> 
> Should be migration_granularity ?

Oh, let me fix this in v2.

Thanks,

> 
>> +		if (t == 0 || t > sbi->segs_per_sec)
>> +			return -EINVAL;
>> +	}
>> +
>>   	if (!strcmp(a->attr.name, "trim_sections"))
>>   		return -EINVAL;
>>   
>> @@ -406,6 +411,7 @@ F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh);
>>   F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ra_nid_pages, ra_nid_pages);
>>   F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, dirty_nats_ratio, dirty_nats_ratio);
>>   F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
>> +F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, migration_granularity, migration_granularity);
>>   F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
>>   F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, cp_interval, interval_time[CP_TIME]);
>>   F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval, interval_time[REQ_TIME]);
>> @@ -460,6 +466,7 @@ static struct attribute *f2fs_attrs[] = {
>>   	ATTR_LIST(min_hot_blocks),
>>   	ATTR_LIST(min_ssr_sections),
>>   	ATTR_LIST(max_victim_search),
>> +	ATTR_LIST(migration_granularity),
>>   	ATTR_LIST(dir_level),
>>   	ATTR_LIST(ram_thresh),
>>   	ATTR_LIST(ra_nid_pages),
>