From: Kemeng Shi <shikemeng@huaweicloud.com>
To: tytso@mit.edu, adilger.kernel@dilger.ca, ojaswin@linux.ibm.com,
ritesh.list@gmail.com
Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
shikemeng@huaweicloud.com
Subject: [PATCH v3 13/20] ext4: remove ac->ac_found > sbi->s_mb_min_to_scan dead check in ext4_mb_check_limits
Date: Sat, 4 Mar 2023 01:21:13 +0800 [thread overview]
Message-ID: <20230303172120.3800725-14-shikemeng@huaweicloud.com> (raw)
In-Reply-To: <20230303172120.3800725-1-shikemeng@huaweicloud.com>
Only call trace of ext4_mb_check_limits is as following:
ext4_mb_complex_scan_group
ext4_mb_measure_extent
ext4_mb_check_limits(ac, e4b, 0);
ext4_mb_check_limits(ac, e4b, 1);
If the first ac->ac_found > sbi->s_mb_max_to_scan check in
ext4_mb_check_limits is met, we will set ac_status to
AC_STATUS_BREAK and call ext4_mb_try_best_found to try to use
ac->ac_b_ex.
If ext4_mb_try_best_found successes, then block allocation finishs,
the removed ac->ac_found > sbi->s_mb_min_to_scan check is not reachable.
If ext4_mb_try_best_found fails, then we set EXT4_MB_HINT_FIRST and
reset ac->ac_b_ex to retry block allocation. We will use any found
free extent in ext4_mb_measure_extent before reach the removed
ac->ac_found > sbi->s_mb_min_to_scan check.
In summary, the removed ac->ac_found > sbi->s_mb_min_to_scan check is
not reachable and we can remove that dead check.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
---
fs/ext4/mballoc.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 16f926675006..5315c67905f6 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2039,8 +2039,7 @@ static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
if (bex->fe_len < gex->fe_len)
return;
- if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
- && bex->fe_group == e4b->bd_group) {
+ if (finish_group && bex->fe_group == e4b->bd_group) {
/* recheck chunk's availability - we don't know
* when it was found (within this lock-unlock
* period or not) */
--
2.30.0
next prev parent reply other threads:[~2023-03-03 9:20 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-03 17:21 [PATCH v3 00/20] Some bugfix and cleanup to mballoc Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 01/20] ext4: set goal start correctly in ext4_mb_normalize_request Kemeng Shi
2023-03-13 2:07 ` Ritesh Harjani
2023-04-06 5:18 ` [PATCH v3 1/20] " Theodore Ts'o
2023-03-03 17:21 ` [PATCH v3 02/20] ext4: allow to find by goal if EXT4_MB_HINT_GOAL_ONLY is set Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 03/20] ext4: get correct ext4_group_info in ext4_mb_prefetch_fini Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 04/20] ext4: correct calculation of s_mb_preallocated Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 05/20] ext4: correct start of used group pa for debug in ext4_mb_use_group_pa Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 06/20] ext4: protect pa->pa_free in ext4_discard_allocated_blocks Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 07/20] ext4: add missed brelse in ext4_free_blocks_simple Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 08/20] ext4: remove unused return value of ext4_mb_try_best_found and ext4_mb_free_metadata Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 09/20] ext4: Remove unnecessary release when memory allocation failed in ext4_mb_init_cache Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 10/20] ext4: remove unnecessary e4b->bd_buddy_page check in ext4_mb_load_buddy_gfp Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 11/20] ext4: remove unnecessary check in ext4_mb_new_blocks Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 12/20] ext4: remove dead check in mb_buddy_mark_free Kemeng Shi
2023-03-03 17:21 ` Kemeng Shi [this message]
2023-03-03 17:21 ` [PATCH v3 14/20] ext4: use best found when complex scan of group finishs Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 15/20] ext4: remove unnecessary exit_meta_group_info tag Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 16/20] ext4: remove unnecessary count2 in ext4_free_data_in_buddy Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 17/20] ext4: remove unnecessary goto in ext4_mb_mark_diskspace_used Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 18/20] ext4: remove repeat assignment to ac_f_ex Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 19/20] ext4: remove comment code ext4_discard_preallocations Kemeng Shi
2023-03-03 17:21 ` [PATCH v3 20/20] ext4: simplify calculation of blkoff in ext4_mb_new_blocks_simple Kemeng Shi
2023-03-16 5:07 ` Theodore Ts'o
2023-03-16 10:19 ` Kemeng Shi
2023-03-17 15:50 ` Theodore Ts'o
2023-03-20 7:31 ` Kemeng Shi
2023-03-10 8:17 ` [PATCH v3 00/20] Some bugfix and cleanup to mballoc Kemeng Shi
2023-03-17 1:52 ` Theodore Ts'o
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