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| author |   Harshad Shirwadkar <harshadshirwadkar@gmail.com> | 2021-04-01 10:21:23 -0700 |
|---|---|---|
| committer |   Theodore Ts'o <tytso@mit.edu> | 2021-04-09 11:34:58 -0400 |
| commit | 67d25186046145748d5fe4c5019d832215e01c1e (patch) | |
| tree | 52f922b1ea1d7aebdc6225feb40b2422295e9656 /fs/ext4/mballoc.c | |
| parent | ext4: fix check to prevent false positive report of incorrect used inodes (diff) | |
| download | linux-dev-67d25186046145748d5fe4c5019d832215e01c1e.tar.xz linux-dev-67d25186046145748d5fe4c5019d832215e01c1e.zip | |
ext4: drop s_mb_bal_lock and convert protected fields to atomic
s_mb_buddies_generated gets used later in this patch series to
determine if the cr 0 and cr 1 optimziations should be performed or
not. Currently, s_mb_buddies_generated is protected under a
spin_lock. In the allocation path, it is better if we don't depend on
the lock and instead read the value atomically. In order to do that,
we drop s_bal_lock altogether and we convert the only two protected
fields by it s_mb_buddies_generated and s_mb_generation_time to atomic
type.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Ritesh Harjani <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20210401172129.189766-2-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/mballoc.c')
| -rw-r--r-- | fs/ext4/mballoc.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index a02fadf4fc84..34ddce5d6e5d 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -816,10 +816,8 @@ void ext4_mb_generate_buddy(struct super_block *sb, clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state)); period = get_cycles() - period; - spin_lock(&sbi->s_bal_lock); - sbi->s_mb_buddies_generated++; - sbi->s_mb_generation_time += period; - spin_unlock(&sbi->s_bal_lock); + atomic_inc(&sbi->s_mb_buddies_generated); + atomic64_add(period, &sbi->s_mb_generation_time); } /* The buddy information is attached the buddy cache inode @@ -2850,7 +2848,6 @@ int ext4_mb_init(struct super_block *sb) } while (i <= sb->s_blocksize_bits + 1); spin_lock_init(&sbi->s_md_lock); - spin_lock_init(&sbi->s_bal_lock); sbi->s_mb_free_pending = 0; INIT_LIST_HEAD(&sbi->s_freed_data_list); @@ -2986,9 +2983,9 @@ int ext4_mb_release(struct super_block *sb) atomic_read(&sbi->s_bal_breaks), atomic_read(&sbi->s_mb_lost_chunks)); ext4_msg(sb, KERN_INFO, - "mballoc: %lu generated and it took %Lu", - sbi->s_mb_buddies_generated, - sbi->s_mb_generation_time); + "mballoc: %u generated and it took %llu", + atomic_read(&sbi->s_mb_buddies_generated), + atomic64_read(&sbi->s_mb_generation_time)); ext4_msg(sb, KERN_INFO, "mballoc: %u preallocated, %u discarded", atomic_read(&sbi->s_mb_preallocated), |