[PATCH 03/10] ext4: return found group directly in ext4_mb_choose_next_group_p2_aligned

From: Kemeng Shi
Date: Fri Jul 21 2023 - 05:10:01 EST


Return good group when it's found in loop to remove unnecessary NULL
initialization of grp and futher check if good group is found after loop.

Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
---
fs/ext4/mballoc.c | 21 +++++++--------------
1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 33ee3991f62c..4031f8e2a660 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -875,7 +875,7 @@ static void ext4_mb_choose_next_group_p2_aligned(struct ext4_allocation_context
enum criteria *new_cr, ext4_group_t *group, ext4_group_t ngroups)
{
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
- struct ext4_group_info *iter, *grp;
+ struct ext4_group_info *iter;
int i;

if (ac->ac_status == AC_STATUS_FOUND)
@@ -884,7 +884,6 @@ static void ext4_mb_choose_next_group_p2_aligned(struct ext4_allocation_context
if (unlikely(sbi->s_mb_stats && ac->ac_flags & EXT4_MB_CR_POWER2_ALIGNED_OPTIMIZED))
atomic_inc(&sbi->s_bal_p2_aligned_bad_suggestions);

- grp = NULL;
for (i = ac->ac_2order; i < MB_NUM_ORDERS(ac->ac_sb); i++) {
if (list_empty(&sbi->s_mb_largest_free_orders[i]))
continue;
@@ -893,28 +892,22 @@ static void ext4_mb_choose_next_group_p2_aligned(struct ext4_allocation_context
read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
continue;
}
- grp = NULL;
list_for_each_entry(iter, &sbi->s_mb_largest_free_orders[i],
bb_largest_free_order_node) {
if (sbi->s_mb_stats)
atomic64_inc(&sbi->s_bal_cX_groups_considered[CR_POWER2_ALIGNED]);
if (likely(ext4_mb_good_group(ac, iter->bb_group, CR_POWER2_ALIGNED))) {
- grp = iter;
- break;
+ *group = iter->bb_group;
+ ac->ac_flags |= EXT4_MB_CR_POWER2_ALIGNED_OPTIMIZED;
+ read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
+ return;
}
}
read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
- if (grp)
- break;
}

- if (!grp) {
- /* Increment cr and search again */
- *new_cr = CR_GOAL_LEN_FAST;
- } else {
- *group = grp->bb_group;
- ac->ac_flags |= EXT4_MB_CR_POWER2_ALIGNED_OPTIMIZED;
- }
+ /* Increment cr and search again if no group is found */
+ *new_cr = CR_GOAL_LEN_FAST;
}

/*
--
2.30.0