From b720d209524fccdd33a499351f2ca880b8c0ffb4 Mon Sep 17 00:00:00 2001
From: Chris Mason <chris.mason@oracle.com>
Date: Fri, 15 Aug 2008 15:34:14 -0400
Subject: [PATCH] Btrfs: Limit the number of async bio submission kthreads to
 the number of devices

Signed-off-by: Chris Mason <chris.mason@oracle.com>
---
 fs/btrfs/disk-io.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 56c54a41dbbb..99bd9f9b9eed 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1348,7 +1348,9 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	 * cannot dynamically grow.
 	 */
 	btrfs_init_workers(&fs_info->workers, fs_info->thread_pool_size);
-	btrfs_init_workers(&fs_info->submit_workers, fs_info->thread_pool_size);
+	btrfs_init_workers(&fs_info->submit_workers,
+			   min_t(u64, fs_devices->num_devices,
+			   fs_info->thread_pool_size));
 
 	/* a higher idle thresh on the submit workers makes it much more
 	 * likely that bios will be send down in a sane order to the
-- 
2.20.1