From 6dbd822487d0a9f14432cb4680415b80656b63a2 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Thu, 10 Jan 2008 15:18:55 +0000 Subject: [GFS2] Reduce inode size by moving i_alloc out of line It is possible to reduce the size of GFS2 inodes by taking the i_alloc structure out of the gfs2_inode. This patch allocates the i_alloc structure whenever its needed, and frees it afterward. This decreases the amount of low memory we use at the expense of requiring a memory allocation for each page or partial page that we write. A quick test with postmark shows that the overhead is not measurable and I also note that OCFS2 use the same approach. In the future I'd like to solve the problem by shrinking down the size of the members of the i_alloc structure, but for now, this reduces the immediate problem of using too much low-memory on x86 and doesn't add too much overhead. Signed-off-by: Steven Whitehouse --- fs/gfs2/main.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/gfs2/main.c') diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c index 653fd5a6203a..88686fcdfb1b 100644 --- a/fs/gfs2/main.c +++ b/fs/gfs2/main.c @@ -31,6 +31,7 @@ static void gfs2_init_inode_once(struct kmem_cache *cachep, void *foo) inode_init_once(&ip->i_inode); spin_lock_init(&ip->i_spin); init_rwsem(&ip->i_rw_mutex); + ip->i_alloc = NULL; } static void gfs2_init_glock_once(struct kmem_cache *cachep, void *foo) -- cgit v1.2.3