ext4: use percpu counter for extent cache count
Use a percpu counter rather than atomic types for shrinker accounting.
There's no need for ultimate accuracy in the shrinker, so this
should come a little more cheaply. The percpu struct is somewhat
large, but there was a big gap before the cache-aligned
s_es_lru_lock anyway, and it fits nicely in there.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 373d46c..1ae5860 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -783,6 +783,7 @@
percpu_counter_destroy(&sbi->s_freeinodes_counter);
percpu_counter_destroy(&sbi->s_dirs_counter);
percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
+ percpu_counter_destroy(&sbi->s_extent_cache_cnt);
brelse(sbi->s_sbh);
#ifdef CONFIG_QUOTA
for (i = 0; i < MAXQUOTAS; i++)
@@ -3688,6 +3689,9 @@
if (!err) {
err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
}
+ if (!err) {
+ err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
+ }
if (err) {
ext4_msg(sb, KERN_ERR, "insufficient memory");
goto failed_mount3;
@@ -3993,6 +3997,7 @@
percpu_counter_destroy(&sbi->s_freeinodes_counter);
percpu_counter_destroy(&sbi->s_dirs_counter);
percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
+ percpu_counter_destroy(&sbi->s_extent_cache_cnt);
if (sbi->s_mmp_tsk)
kthread_stop(sbi->s_mmp_tsk);
failed_mount2: