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authorJosef Bacik <josef@redhat.com>2010-02-02 15:50:10 -0500
committerChris Mason <chris.mason@oracle.com>2010-02-04 11:31:45 -0500
commitefd049fb26a162c3830fd3cb1001fdc09b147f3b (patch)
treecaedb4f8b1133b209360bd25ff3b2ddd1dc737c0 /fs/btrfs/inode.c
parent7a7965f83e89f0be506a96769938a721e4e5ae50 (diff)
Btrfs: do not try and lookup the file extent when finishing ordered io
When running the following fio job [torrent] filename=torrent-test rw=randwrite size=4g filesize=4g bs=4k ioengine=sync you would see long stalls where no work was being done. That is because we were doing all this extra work to read in the file extent outside of the transaction, however in the random io case this ends up hurting us because the file extents are not there to begin with. So axe this logic, since we end up reading in the file extent when we go to update it anyway. This took the fio job from 11 mb/s with several ~10 second stalls to 24 mb/s to a couple of 1-2 second stalls. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/inode.c')
-rw-r--r--fs/btrfs/inode.c46
1 files changed, 2 insertions, 44 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8cd109972fa6..6782aa19130d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1681,24 +1681,6 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1681 * before we start the transaction. It limits the amount of btree 1681 * before we start the transaction. It limits the amount of btree
1682 * reads required while inside the transaction. 1682 * reads required while inside the transaction.
1683 */ 1683 */
1684static noinline void reada_csum(struct btrfs_root *root,
1685 struct btrfs_path *path,
1686 struct btrfs_ordered_extent *ordered_extent)
1687{
1688 struct btrfs_ordered_sum *sum;
1689 u64 bytenr;
1690
1691 sum = list_entry(ordered_extent->list.next, struct btrfs_ordered_sum,
1692 list);
1693 bytenr = sum->sums[0].bytenr;
1694
1695 /*
1696 * we don't care about the results, the point of this search is
1697 * just to get the btree leaves into ram
1698 */
1699 btrfs_lookup_csum(NULL, root->fs_info->csum_root, path, bytenr, 0);
1700}
1701
1702/* as ordered data IO finishes, this gets called so we can finish 1684/* as ordered data IO finishes, this gets called so we can finish
1703 * an ordered extent if the range of bytes in the file it covers are 1685 * an ordered extent if the range of bytes in the file it covers are
1704 * fully written. 1686 * fully written.
@@ -1709,7 +1691,6 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
1709 struct btrfs_trans_handle *trans; 1691 struct btrfs_trans_handle *trans;
1710 struct btrfs_ordered_extent *ordered_extent = NULL; 1692 struct btrfs_ordered_extent *ordered_extent = NULL;
1711 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 1693 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1712 struct btrfs_path *path;
1713 int compressed = 0; 1694 int compressed = 0;
1714 int ret; 1695 int ret;
1715 1696
@@ -1717,32 +1698,9 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
1717 if (!ret) 1698 if (!ret)
1718 return 0; 1699 return 0;
1719 1700
1720 /* 1701 ordered_extent = btrfs_lookup_ordered_extent(inode, start);
1721 * before we join the transaction, try to do some of our IO.
1722 * This will limit the amount of IO that we have to do with
1723 * the transaction running. We're unlikely to need to do any
1724 * IO if the file extents are new, the disk_i_size checks
1725 * covers the most common case.
1726 */
1727 if (start < BTRFS_I(inode)->disk_i_size) {
1728 path = btrfs_alloc_path();
1729 if (path) {
1730 ret = btrfs_lookup_file_extent(NULL, root, path,
1731 inode->i_ino,
1732 start, 0);
1733 ordered_extent = btrfs_lookup_ordered_extent(inode,
1734 start);
1735 if (!list_empty(&ordered_extent->list)) {
1736 btrfs_release_path(root, path);
1737 reada_csum(root, path, ordered_extent);
1738 }
1739 btrfs_free_path(path);
1740 }
1741 }
1742
1743 if (!ordered_extent)
1744 ordered_extent = btrfs_lookup_ordered_extent(inode, start);
1745 BUG_ON(!ordered_extent); 1702 BUG_ON(!ordered_extent);
1703
1746 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { 1704 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
1747 BUG_ON(!list_empty(&ordered_extent->list)); 1705 BUG_ON(!list_empty(&ordered_extent->list));
1748 ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent); 1706 ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);