From 34eefc06a06f496b92c3267a0601129a932c7174 Mon Sep 17 00:00:00 2001
From: Dave Chinner <dchinner@redhat.com>
Date: Thu, 27 Jun 2013 16:04:47 +1000
Subject: [PATCH] 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 <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
---
fs/xfs/xfs_dir2_leaf.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/xfs/xfs_dir2_leaf.c b/fs/xfs/xfs_dir2_leaf.c
index da71a1819d780..bb22aac9fc01a 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;
--
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