From d5ee37bcb1dff9c1d1cac5f7e5752309f1ff66b6 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Thu, 24 Jul 2014 11:37:10 +0800 Subject: [PATCH] Btrfs: make the device lock and its protected data in the same cacheline The lock in btrfs_device structure was far away from its protected data, it would make CPU load the cache line twice when we accessed them, move them together. Signed-off-by: Miao Xie Signed-off-by: Chris Mason --- fs/btrfs/volumes.h | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 2aaa00c47816..6fcc8eae7834 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -36,30 +36,31 @@ struct btrfs_device { struct list_head dev_list; struct list_head dev_alloc_list; struct btrfs_fs_devices *fs_devices; + struct btrfs_root *dev_root; + struct rcu_string *name; + + u64 generation; + + spinlock_t io_lock ____cacheline_aligned; + int running_pending; /* regular prio bios */ struct btrfs_pending_bios pending_bios; /* WRITE_SYNC bios */ struct btrfs_pending_bios pending_sync_bios; - u64 generation; - int running_pending; + struct block_device *bdev; + + /* the mode sent to blkdev_get */ + fmode_t mode; + int writeable; int in_fs_metadata; int missing; int can_discard; int is_tgtdev_for_dev_replace; - spinlock_t io_lock; - /* the mode sent to blkdev_get */ - fmode_t mode; - - struct block_device *bdev; - - - struct rcu_string *name; - /* the internal btrfs device id */ u64 devid; @@ -83,7 +84,6 @@ struct btrfs_device { /* minimal io size for this device */ u32 sector_size; - /* physical drive uuid (or lvm uuid) */ u8 uuid[BTRFS_UUID_SIZE]; @@ -107,7 +107,6 @@ struct btrfs_device { struct radix_tree_root reada_zones; struct radix_tree_root reada_extents; - /* disk I/O failure stats. For detailed description refer to * enum btrfs_dev_stat_values in ioctl.h */ int dev_stats_valid; -- 2.39.2