Btrfs: More throttle tuning
* Make walk_down_tree wake up throttled tasks more often
* Make walk_down_tree call cond_resched during long loops
* As the size of the ref cache grows, wait longer in throttle
* Get rid of the reada code in walk_down_tree, the leaves don't get
read anymore, thanks to the ref cache.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 9d84daf..cf73342 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -210,7 +210,9 @@
static void throttle_on_drops(struct btrfs_root *root)
{
struct btrfs_fs_info *info = root->fs_info;
+ int harder_count = 0;
+harder:
if (atomic_read(&info->throttles)) {
DEFINE_WAIT(wait);
int thr;
@@ -226,6 +228,19 @@
schedule();
finish_wait(&info->transaction_throttle, &wait);
} while (thr == atomic_read(&info->throttle_gen));
+ harder_count++;
+
+ if (root->fs_info->total_ref_cache_size > 1 * 1024 * 1024 &&
+ harder_count < 2)
+ goto harder;
+
+ if (root->fs_info->total_ref_cache_size > 5 * 1024 * 1024 &&
+ harder_count < 10)
+ goto harder;
+
+ if (root->fs_info->total_ref_cache_size > 10 * 1024 * 1024 &&
+ harder_count < 20)
+ goto harder;
}
}