From: Dave Chinner Date: Thu, 27 Jun 2013 06:04:47 +0000 (+1000) Subject: xfs: plug directory buffer readahead X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=34eefc06a06f496b92c3267a0601129a932c7174;p=linux-beck.git xfs: plug directory buffer readahead Similar to bulkstat inode chunk readahead, we need to plug directory data buffer readahead during getdents to ensure that we can merge adjacent readahead requests and sort out of order requests optimally before they are dispatched. This improves the readahead efficiency and reduces the IO load it generates as the IO patterns are significantly better for both contiguous and fragmented directories. Signed-off-by: Dave Chinner Reviewed-by: Mark Tinguely Signed-off-by: Ben Myers --- diff --git a/fs/xfs/xfs_dir2_leaf.c b/fs/xfs/xfs_dir2_leaf.c index da71a1819d78..bb22aac9fc01 100644 --- a/fs/xfs/xfs_dir2_leaf.c +++ b/fs/xfs/xfs_dir2_leaf.c @@ -1108,6 +1108,7 @@ xfs_dir2_leaf_readbuf( struct xfs_mount *mp = dp->i_mount; struct xfs_buf *bp = *bpp; struct xfs_bmbt_irec *map = mip->map; + struct blk_plug plug; int error = 0; int length; int i; @@ -1236,6 +1237,7 @@ xfs_dir2_leaf_readbuf( /* * Do we need more readahead? */ + blk_start_plug(&plug); for (mip->ra_index = mip->ra_offset = i = 0; mip->ra_want > mip->ra_current && i < mip->map_blocks; i += mp->m_dirblkfsbs) { @@ -1287,6 +1289,7 @@ xfs_dir2_leaf_readbuf( } } } + blk_finish_plug(&plug); out: *bpp = bp;