From 138211515c102807a16c02fdc15feef1f6ef8124 Mon Sep 17 00:00:00 2001 From: Tao Ma Date: Wed, 25 Feb 2009 00:53:23 +0800 Subject: ocfs2: Optimize inode allocation by remembering last group In ocfs2, the inode block search looks for the "emptiest" inode group to allocate from. So if an inode alloc file has many equally (or almost equally) empty groups, new inodes will tend to get spread out amongst them, which in turn can put them all over the disk. This is undesirable because directory operations on conceptually "nearby" inodes force a large number of seeks. So we add ip_last_used_group in core directory inodes which records the last used allocation group. Another field named ip_last_used_slot is also added in case inode stealing happens. When claiming new inode, we passed in directory's inode so that the allocation can use this information. For more details, please see http://oss.oracle.com/osswiki/OCFS2/DesignDocs/InodeAllocationStrategy. Signed-off-by: Tao Ma Signed-off-by: Mark Fasheh --- fs/ocfs2/inode.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/ocfs2/inode.c') diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c index f1f77b2..4a88bce 100644 --- a/fs/ocfs2/inode.c +++ b/fs/ocfs2/inode.c @@ -352,6 +352,8 @@ void ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe, ocfs2_set_inode_flags(inode); + OCFS2_I(inode)->ip_last_used_slot = 0; + OCFS2_I(inode)->ip_last_used_group = 0; mlog_exit_void(); } -- cgit v1.1