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Message-ID: <36ebed2d-36e9-4e0b-ba2c-f85ad35f4a7b@kernel.org>
Date: Wed, 21 Feb 2024 10:18:17 +0800
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User-Agent: Mozilla Thunderbird
Subject: Re: [f2fs-dev] [PATCH v2] f2fs: kill heap-based allocation
To: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net
References: <20240207164620.1536038-1-jaegeuk@kernel.org>
 <ZdUQ6uKYyfzn5Fhv@google.com>
 <1a9d9c59-dbba-4d9e-8804-2fb92c56b5b3@kernel.org>
 <ZdVYfHg2R8B1Uj2r@google.com>
Content-Language: en-US
From: Chao Yu <chao@kernel.org>
In-Reply-To: <ZdVYfHg2R8B1Uj2r@google.com>
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On 2024/2/21 9:57, Jaegeuk Kim wrote:
> On 02/21, Chao Yu wrote:
>> On 2024/2/21 4:51, Jaegeuk Kim wrote:
>>> No one uses this feature. Let's kill it.
>>>
>>> Reviewed-by: Daeho Jeong <daehojeong@google.com>
>>> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
>>> ---
>>>
>>>    Change log from v1:
>>>     - keep mount options but give warnings instead
>>>
>>>    Documentation/filesystems/f2fs.rst |  4 +--
>>>    fs/f2fs/gc.c                       |  5 ++-
>>>    fs/f2fs/segment.c                  | 54 ++++--------------------------
>>>    fs/f2fs/segment.h                  | 10 ------
>>>    fs/f2fs/super.c                    |  9 +----
>>>    5 files changed, 11 insertions(+), 71 deletions(-)
>>>
>>> diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
>>> index 9ac5083dae8e..c30a800604fd 100644
>>> --- a/Documentation/filesystems/f2fs.rst
>>> +++ b/Documentation/filesystems/f2fs.rst
>>> @@ -126,9 +126,7 @@ norecovery		 Disable the roll-forward recovery routine, mounted read-
>>>    discard/nodiscard	 Enable/disable real-time discard in f2fs, if discard is
>>>    			 enabled, f2fs will issue discard/TRIM commands when a
>>>    			 segment is cleaned.
>>> -no_heap			 Disable heap-style segment allocation which finds free
>>> -			 segments for data from the beginning of main area, while
>>> -			 for node from the end of main area.
>>> +no_heap			 Deprecated.
>>
>> heap/no_heap			Deprecated
>>
>> Otherwise, it looks good to me.
>>
>> Reviewed-by: Chao Yu <chao@kernel.org>
>>
>> BTW, do we need to kill heap-based allocation in mkfs.f2fs as well?
> 
> I was about to work on it after kernel change tho. Can you write one? :)

No problem.

Thanks,

> 
>>
>> Thanks,
>>
>>>    nouser_xattr		 Disable Extended User Attributes. Note: xattr is enabled
>>>    			 by default if CONFIG_F2FS_FS_XATTR is selected.
>>>    noacl			 Disable POSIX Access Control List. Note: acl is enabled
>>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
>>> index 501b93b45b6c..a089a938355b 100644
>>> --- a/fs/f2fs/gc.c
>>> +++ b/fs/f2fs/gc.c
>>> @@ -280,12 +280,11 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
>>>    			p->max_search > sbi->max_victim_search)
>>>    		p->max_search = sbi->max_victim_search;
>>> -	/* let's select beginning hot/small space first in no_heap mode*/
>>> +	/* let's select beginning hot/small space first. */
>>>    	if (f2fs_need_rand_seg(sbi))
>>>    		p->offset = get_random_u32_below(MAIN_SECS(sbi) *
>>>    						SEGS_PER_SEC(sbi));
>>> -	else if (test_opt(sbi, NOHEAP) &&
>>> -		(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
>>> +	else if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
>>>    		p->offset = 0;
>>>    	else
>>>    		p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>> index 94c4f7b16c19..09af17af4e7a 100644
>>> --- a/fs/f2fs/segment.c
>>> +++ b/fs/f2fs/segment.c
>>> @@ -2634,16 +2634,14 @@ static int is_next_segment_free(struct f2fs_sb_info *sbi,
>>>     * This function should be returned with success, otherwise BUG
>>>     */
>>>    static void get_new_segment(struct f2fs_sb_info *sbi,
>>> -			unsigned int *newseg, bool new_sec, int dir)
>>> +			unsigned int *newseg, bool new_sec)
>>>    {
>>>    	struct free_segmap_info *free_i = FREE_I(sbi);
>>>    	unsigned int segno, secno, zoneno;
>>>    	unsigned int total_zones = MAIN_SECS(sbi) / sbi->secs_per_zone;
>>>    	unsigned int hint = GET_SEC_FROM_SEG(sbi, *newseg);
>>>    	unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
>>> -	unsigned int left_start = hint;
>>>    	bool init = true;
>>> -	int go_left = 0;
>>>    	int i;
>>>    	spin_lock(&free_i->segmap_lock);
>>> @@ -2657,30 +2655,10 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
>>>    find_other_zone:
>>>    	secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
>>>    	if (secno >= MAIN_SECS(sbi)) {
>>> -		if (dir == ALLOC_RIGHT) {
>>> -			secno = find_first_zero_bit(free_i->free_secmap,
>>> +		secno = find_first_zero_bit(free_i->free_secmap,
>>>    							MAIN_SECS(sbi));
>>> -			f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
>>> -		} else {
>>> -			go_left = 1;
>>> -			left_start = hint - 1;
>>> -		}
>>> -	}
>>> -	if (go_left == 0)
>>> -		goto skip_left;
>>> -
>>> -	while (test_bit(left_start, free_i->free_secmap)) {
>>> -		if (left_start > 0) {
>>> -			left_start--;
>>> -			continue;
>>> -		}
>>> -		left_start = find_first_zero_bit(free_i->free_secmap,
>>> -							MAIN_SECS(sbi));
>>> -		f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi));
>>> -		break;
>>> +		f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
>>>    	}
>>> -	secno = left_start;
>>> -skip_left:
>>>    	segno = GET_SEG_FROM_SEC(sbi, secno);
>>>    	zoneno = GET_ZONE_FROM_SEC(sbi, secno);
>>> @@ -2691,21 +2669,13 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
>>>    		goto got_it;
>>>    	if (zoneno == old_zoneno)
>>>    		goto got_it;
>>> -	if (dir == ALLOC_LEFT) {
>>> -		if (!go_left && zoneno + 1 >= total_zones)
>>> -			goto got_it;
>>> -		if (go_left && zoneno == 0)
>>> -			goto got_it;
>>> -	}
>>>    	for (i = 0; i < NR_CURSEG_TYPE; i++)
>>>    		if (CURSEG_I(sbi, i)->zone == zoneno)
>>>    			break;
>>>    	if (i < NR_CURSEG_TYPE) {
>>>    		/* zone is in user, try another */
>>> -		if (go_left)
>>> -			hint = zoneno * sbi->secs_per_zone - 1;
>>> -		else if (zoneno + 1 >= total_zones)
>>> +		if (zoneno + 1 >= total_zones)
>>>    			hint = 0;
>>>    		else
>>>    			hint = (zoneno + 1) * sbi->secs_per_zone;
>>> @@ -2763,8 +2733,7 @@ static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
>>>    	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
>>>    		return 0;
>>> -	if (test_opt(sbi, NOHEAP) &&
>>> -		(seg_type == CURSEG_HOT_DATA || IS_NODESEG(seg_type)))
>>> +	if (seg_type == CURSEG_HOT_DATA || IS_NODESEG(seg_type))
>>>    		return 0;
>>>    	if (SIT_I(sbi)->last_victim[ALLOC_NEXT])
>>> @@ -2784,21 +2753,12 @@ static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
>>>    static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
>>>    {
>>>    	struct curseg_info *curseg = CURSEG_I(sbi, type);
>>> -	unsigned short seg_type = curseg->seg_type;
>>>    	unsigned int segno = curseg->segno;
>>> -	int dir = ALLOC_LEFT;
>>>    	if (curseg->inited)
>>> -		write_sum_page(sbi, curseg->sum_blk,
>>> -				GET_SUM_BLOCK(sbi, segno));
>>> -	if (seg_type == CURSEG_WARM_DATA || seg_type == CURSEG_COLD_DATA)
>>> -		dir = ALLOC_RIGHT;
>>> -
>>> -	if (test_opt(sbi, NOHEAP))
>>> -		dir = ALLOC_RIGHT;
>>> -
>>> +		write_sum_page(sbi, curseg->sum_blk, GET_SUM_BLOCK(sbi, segno));
>>>    	segno = __get_next_segno(sbi, type);
>>> -	get_new_segment(sbi, &segno, new_sec, dir);
>>> +	get_new_segment(sbi, &segno, new_sec);
>>>    	curseg->next_segno = segno;
>>>    	reset_curseg(sbi, type, 1);
>>>    	curseg->alloc_type = LFS;
>>> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
>>> index 6fadfb634aac..0f1a5210c163 100644
>>> --- a/fs/f2fs/segment.h
>>> +++ b/fs/f2fs/segment.h
>>> @@ -131,16 +131,6 @@ static inline void sanity_check_seg_type(struct f2fs_sb_info *sbi,
>>>    #define SECTOR_TO_BLOCK(sectors)					\
>>>    	((sectors) >> F2FS_LOG_SECTORS_PER_BLOCK)
>>> -/*
>>> - * indicate a block allocation direction: RIGHT and LEFT.
>>> - * RIGHT means allocating new sections towards the end of volume.
>>> - * LEFT means the opposite direction.
>>> - */
>>> -enum {
>>> -	ALLOC_RIGHT = 0,
>>> -	ALLOC_LEFT
>>> -};
>>> -
>>>    /*
>>>     * In the victim_sel_policy->alloc_mode, there are three block allocation modes.
>>>     * LFS writes data sequentially with cleaning operations.
>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>> index 5aaf44c4698b..916e82e9c307 100644
>>> --- a/fs/f2fs/super.c
>>> +++ b/fs/f2fs/super.c
>>> @@ -733,10 +733,8 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
>>>    			clear_opt(sbi, DISCARD);
>>>    			break;
>>>    		case Opt_noheap:
>>> -			set_opt(sbi, NOHEAP);
>>> -			break;
>>>    		case Opt_heap:
>>> -			clear_opt(sbi, NOHEAP);
>>> +			f2fs_warn(sbi, "heap/no_heap options were deprecated");
>>>    			break;
>>>    #ifdef CONFIG_F2FS_FS_XATTR
>>>    		case Opt_user_xattr:
>>> @@ -1962,10 +1960,6 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
>>>    	} else {
>>>    		seq_puts(seq, ",nodiscard");
>>>    	}
>>> -	if (test_opt(sbi, NOHEAP))
>>> -		seq_puts(seq, ",no_heap");
>>> -	else
>>> -		seq_puts(seq, ",heap");
>>>    #ifdef CONFIG_F2FS_FS_XATTR
>>>    	if (test_opt(sbi, XATTR_USER))
>>>    		seq_puts(seq, ",user_xattr");
>>> @@ -2142,7 +2136,6 @@ static void default_options(struct f2fs_sb_info *sbi, bool remount)
>>>    	set_opt(sbi, INLINE_XATTR);
>>>    	set_opt(sbi, INLINE_DATA);
>>>    	set_opt(sbi, INLINE_DENTRY);
>>> -	set_opt(sbi, NOHEAP);
>>>    	set_opt(sbi, MERGE_CHECKPOINT);
>>>    	F2FS_OPTION(sbi).unusable_cap = 0;
>>>    	sbi->sb->s_flags |= SB_LAZYTIME;