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| author | Ojaswin Mujoo <ojaswin@linux.ibm.com> | 2023-05-30 15:33:46 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2023-06-27 02:34:56 +0300 |
| commit | 3c6296046c85333bc52555a670a9093d9e2657bb (patch) | |
| tree | 040a34b7c9ec8d44aa72564ac432f0603b798754 /fs/ext4 | |
| parent | 1b420011210802a7a1b1e99f30bc1d62c352ac71 (diff) | |
| download | linux-3c6296046c85333bc52555a670a9093d9e2657bb.tar.xz | |
ext4: Don't skip prefetching BLOCK_UNINIT groups
Currently, ext4_mb_prefetch() and ext4_mb_prefetch_fini() skip
BLOCK_UNINIT groups since fetching their bitmaps doesn't need disk IO.
As a consequence, we end not initializing the buddy structures and CR0/1
lists for these BGs, even though it can be done without any disk IO
overhead. Hence, don't skip such BGs during prefetch and prefetch_fini.
This improves the accuracy of CR0/1 allocation as earlier, we could have
essentially empty BLOCK_UNINIT groups being ignored by CR0/1 due to their buddy
not being initialized, leading to slower CR2 allocations. With this patch CR0/1
will be able to discover these groups as well, thus improving performance.
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/dc3130b8daf45ffe63d8a3c1edcf00eb8ba70e1f.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/mballoc.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 704f8e5608f7..fb9780bb1b54 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2589,9 +2589,7 @@ ext4_group_t ext4_mb_prefetch(struct super_block *sb, ext4_group_t group, */ if (gdp && grp && !EXT4_MB_GRP_TEST_AND_SET_READ(grp) && EXT4_MB_GRP_NEED_INIT(grp) && - ext4_free_group_clusters(sb, gdp) > 0 && - !(ext4_has_group_desc_csum(sb) && - (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))) { + ext4_free_group_clusters(sb, gdp) > 0 ) { bh = ext4_read_block_bitmap_nowait(sb, group, true); if (bh && !IS_ERR(bh)) { if (!buffer_uptodate(bh) && cnt) @@ -2632,9 +2630,7 @@ void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group, grp = ext4_get_group_info(sb, group); if (grp && gdp && EXT4_MB_GRP_NEED_INIT(grp) && - ext4_free_group_clusters(sb, gdp) > 0 && - !(ext4_has_group_desc_csum(sb) && - (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))) { + ext4_free_group_clusters(sb, gdp) > 0) { if (ext4_mb_init_group(sb, group, GFP_NOFS)) break; } |