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| author | Kemeng Shi <shikemeng@huaweicloud.com> | 2024-04-24 14:19:00 +0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2024-05-03 00:12:32 -0400 |
| commit | 9c97c34a998a01bc0cf970b1685456bc2ea16b64 (patch) | |
| tree | 883767919db601483df87e6c4db57cdc472ebda6 /fs/ext4 | |
| parent | a11adf7be9d8baefe798eab49c356ab8e3924f0e (diff) | |
| download | linux-9c97c34a998a01bc0cf970b1685456bc2ea16b64.tar.gz linux-9c97c34a998a01bc0cf970b1685456bc2ea16b64.tar.bz2 linux-9c97c34a998a01bc0cf970b1685456bc2ea16b64.zip | |
ext4: keep "prefetch_grp" and "nr" consistent
Keep "prefetch_grp" and "nr" consistent to avoid to call
ext4_mb_prefetch_fini with non-prefetched groups.
When we step into next criteria, "prefetch_grp" is set to prefetch start
of new criteria while "nr" is number of the prefetched group in previous
criteria. If previous criteria and next criteria are both inexpensive
(< CR_GOAL_LEN_SLOW) and prefetch_ios reachs sbi->s_mb_prefetch_limit
in previous criteria, "prefetch_grp" and "nr" will be inconsistent and
may introduce unexpected cost to do ext4_mb_init_group for non-prefetched
groups.
Reset "nr" to 0 when we reset "prefetch_grp" to goal group to keep them
consistent.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240424061904.987525-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/mballoc.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index c65fac9b8c72..33e6a3ebdb55 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2860,6 +2860,7 @@ repeat: group = ac->ac_g_ex.fe_group; ac->ac_groups_linear_remaining = sbi->s_mb_max_linear_groups; prefetch_grp = group; + nr = 0; for (i = 0, new_cr = cr; i < ngroups; i++, ext4_mb_choose_next_group(ac, &new_cr, &group, ngroups)) { |