2024-04-11 08:50:21

by Chao Yu

[permalink] [raw]
Subject: [PATCH v2 1/2] f2fs: use per-log target_bitmap to improve lookup performace of ssr allocation

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 <[email protected]>
---
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 */
--
2.40.1



2024-04-23 02:08:03

by Chao Yu

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] f2fs: use per-log target_bitmap to improve lookup performace of ssr allocation

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 <[email protected]>
> ---
> 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 */