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Message-ID: <41187ebc-cfc5-49a5-93e8-0350d2686d42@kernel.org>
Date: Fri, 31 May 2024 09:10:35 +0800
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Subject: Re: [f2fs-dev] [PATCH v2 1/2] f2fs: use per-log target_bitmap to
 improve lookup performace of ssr allocation
To: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net
References: <20240411082354.1691820-1-chao@kernel.org>
 <11d5d736-bae5-4a71-b400-087b8722893c@kernel.org>
 <03647897-8b1f-4c82-b2b6-0aa0704bed05@kernel.org>
 <ZlkOLN0BugwQ2p5p@google.com>
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From: Chao Yu <chao@kernel.org>
In-Reply-To: <ZlkOLN0BugwQ2p5p@google.com>
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On 2024/5/31 7:39, Jaegeuk Kim wrote:
> On 05/29, Chao Yu wrote:
>> Ping,

Jaegeuk,

> 
> Chao, sorry, I might need some time to take a look at the change cautiously.

No problem, I've done some tests on this patch, though, I will keeping this in
my queue, and do test base on the queue whenever it comes new patches.

Thanks,

> 
>>
>> On 2024/4/23 10:07, Chao Yu wrote:
>>> Jaegeuk, any comments for this serials?
>>>
>>> On 2024/4/11 16:23, Chao Yu wrote:
>>>> After commit 899fee36fac0 ("f2fs: fix to avoid data corruption by
>>>> forbidding SSR overwrite"), valid block bitmap of current openned
>>>> segment is fixed, let's introduce a per-log bitmap instead of temp
>>>> bitmap to avoid unnecessary calculation overhead whenever allocating
>>>> free slot w/ SSR allocator.
>>>>
>>>> Signed-off-by: Chao Yu <chao@kernel.org>
>>>> ---
>>>> v2:
>>>> - rebase to last dev-test branch.
>>>>    fs/f2fs/segment.c | 30 ++++++++++++++++++++++--------
>>>>    fs/f2fs/segment.h |  1 +
>>>>    2 files changed, 23 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>>> index 6474b7338e81..af716925db19 100644
>>>> --- a/fs/f2fs/segment.c
>>>> +++ b/fs/f2fs/segment.c
>>>> @@ -2840,31 +2840,39 @@ static int new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
>>>>        return 0;
>>>>    }
>>>> -static int __next_free_blkoff(struct f2fs_sb_info *sbi,
>>>> -                    int segno, block_t start)
>>>> +static void __get_segment_bitmap(struct f2fs_sb_info *sbi,
>>>> +                    unsigned long *target_map,
>>>> +                    int segno)
>>>>    {
>>>>        struct seg_entry *se = get_seg_entry(sbi, segno);
>>>>        int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
>>>> -    unsigned long *target_map = SIT_I(sbi)->tmp_map;
>>>>        unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
>>>>        unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
>>>>        int i;
>>>>        for (i = 0; i < entries; i++)
>>>>            target_map[i] = ckpt_map[i] | cur_map[i];
>>>> +}
>>>> +
>>>> +static int __next_free_blkoff(struct f2fs_sb_info *sbi, unsigned long *bitmap,
>>>> +                    int segno, block_t start)
>>>> +{
>>>> +    __get_segment_bitmap(sbi, bitmap, segno);
>>>> -    return __find_rev_next_zero_bit(target_map, BLKS_PER_SEG(sbi), start);
>>>> +    return __find_rev_next_zero_bit(bitmap, BLKS_PER_SEG(sbi), start);
>>>>    }
>>>>    static int f2fs_find_next_ssr_block(struct f2fs_sb_info *sbi,
>>>> -        struct curseg_info *seg)
>>>> +                    struct curseg_info *seg)
>>>>    {
>>>> -    return __next_free_blkoff(sbi, seg->segno, seg->next_blkoff + 1);
>>>> +    return __find_rev_next_zero_bit(seg->target_map,
>>>> +                BLKS_PER_SEG(sbi), seg->next_blkoff + 1);
>>>>    }
>>>>    bool f2fs_segment_has_free_slot(struct f2fs_sb_info *sbi, int segno)
>>>>    {
>>>> -    return __next_free_blkoff(sbi, segno, 0) < BLKS_PER_SEG(sbi);
>>>> +    return __next_free_blkoff(sbi, SIT_I(sbi)->tmp_map, segno, 0) <
>>>> +                            BLKS_PER_SEG(sbi);
>>>>    }
>>>>    /*
>>>> @@ -2890,7 +2898,8 @@ static int change_curseg(struct f2fs_sb_info *sbi, int type)
>>>>        reset_curseg(sbi, type, 1);
>>>>        curseg->alloc_type = SSR;
>>>> -    curseg->next_blkoff = __next_free_blkoff(sbi, curseg->segno, 0);
>>>> +    curseg->next_blkoff = __next_free_blkoff(sbi, curseg->target_map,
>>>> +                            curseg->segno, 0);
>>>>        sum_page = f2fs_get_sum_page(sbi, new_segno);
>>>>        if (IS_ERR(sum_page)) {
>>>> @@ -4635,6 +4644,10 @@ static int build_curseg(struct f2fs_sb_info *sbi)
>>>>                    sizeof(struct f2fs_journal), GFP_KERNEL);
>>>>            if (!array[i].journal)
>>>>                return -ENOMEM;
>>>> +        array[i].target_map = f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE,
>>>> +                                GFP_KERNEL);
>>>> +        if (!array[i].target_map)
>>>> +            return -ENOMEM;
>>>>            if (i < NR_PERSISTENT_LOG)
>>>>                array[i].seg_type = CURSEG_HOT_DATA + i;
>>>>            else if (i == CURSEG_COLD_DATA_PINNED)
>>>> @@ -5453,6 +5466,7 @@ static void destroy_curseg(struct f2fs_sb_info *sbi)
>>>>        for (i = 0; i < NR_CURSEG_TYPE; i++) {
>>>>            kfree(array[i].sum_blk);
>>>>            kfree(array[i].journal);
>>>> +        kfree(array[i].target_map);
>>>>        }
>>>>        kfree(array);
>>>>    }
>>>> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
>>>> index e1c0f418aa11..10f3e44f036f 100644
>>>> --- a/fs/f2fs/segment.h
>>>> +++ b/fs/f2fs/segment.h
>>>> @@ -292,6 +292,7 @@ struct curseg_info {
>>>>        struct f2fs_summary_block *sum_blk;    /* cached summary block */
>>>>        struct rw_semaphore journal_rwsem;    /* protect journal area */
>>>>        struct f2fs_journal *journal;        /* cached journal info */
>>>> +    unsigned long *target_map;        /* bitmap for SSR allocator */
>>>>        unsigned char alloc_type;        /* current allocation type */
>>>>        unsigned short seg_type;        /* segment type like CURSEG_XXX_TYPE */
>>>>        unsigned int segno;            /* current segment number */
>>>
>>>
>>> _______________________________________________
>>> Linux-f2fs-devel mailing list
>>> Linux-f2fs-devel@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel