| Message ID | 20200313210954.148686-2-josef@toxicpanda.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Drop some mis-uses of READA | expand |
On 2020/3/14 上午5:09, Josef Bacik wrote: > READA will generate a lot of extra reads for adjacent nodes, but when > running delayed refs we have no idea if the next ref is going to be > adjacent or not, so this potentially just generates a lot of extra IO. > To make matters worse each ref is truly just looking for one item, it > doesn't generally search forward, so we simply don't need it here. > > Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Thanks, Qu > --- > fs/btrfs/extent-tree.c | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index a24ef1cef9fa..8e5b49baad98 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -1469,7 +1469,6 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, > if (!path) > return -ENOMEM; > > - path->reada = READA_FORWARD; > path->leave_spinning = 1; > /* this will setup the path even if it fails to insert the back ref */ > ret = insert_inline_extent_backref(trans, path, bytenr, num_bytes, > @@ -1494,7 +1493,6 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, > btrfs_mark_buffer_dirty(leaf); > btrfs_release_path(path); > > - path->reada = READA_FORWARD; > path->leave_spinning = 1; > /* now insert the actual backref */ > ret = insert_extent_backref(trans, path, bytenr, parent, root_objectid, > @@ -1604,7 +1602,6 @@ static int run_delayed_extent_op(struct btrfs_trans_handle *trans, > } > > again: > - path->reada = READA_FORWARD; > path->leave_spinning = 1; > ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 1); > if (ret < 0) { > @@ -2999,7 +2996,6 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans, > if (!path) > return -ENOMEM; > > - path->reada = READA_FORWARD; > path->leave_spinning = 1; > > is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID; >
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index a24ef1cef9fa..8e5b49baad98 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -1469,7 +1469,6 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, if (!path) return -ENOMEM; - path->reada = READA_FORWARD; path->leave_spinning = 1; /* this will setup the path even if it fails to insert the back ref */ ret = insert_inline_extent_backref(trans, path, bytenr, num_bytes, @@ -1494,7 +1493,6 @@ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, btrfs_mark_buffer_dirty(leaf); btrfs_release_path(path); - path->reada = READA_FORWARD; path->leave_spinning = 1; /* now insert the actual backref */ ret = insert_extent_backref(trans, path, bytenr, parent, root_objectid, @@ -1604,7 +1602,6 @@ static int run_delayed_extent_op(struct btrfs_trans_handle *trans, } again: - path->reada = READA_FORWARD; path->leave_spinning = 1; ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 1); if (ret < 0) { @@ -2999,7 +2996,6 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans, if (!path) return -ENOMEM; - path->reada = READA_FORWARD; path->leave_spinning = 1; is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
READA will generate a lot of extra reads for adjacent nodes, but when running delayed refs we have no idea if the next ref is going to be adjacent or not, so this potentially just generates a lot of extra IO. To make matters worse each ref is truly just looking for one item, it doesn't generally search forward, so we simply don't need it here. Signed-off-by: Josef Bacik <josef@toxicpanda.com> --- fs/btrfs/extent-tree.c | 4 ---- 1 file changed, 4 deletions(-)