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/inode.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'fs/gfs2/inode.c') diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index 53bca99..c84764a 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -711,9 +711,10 @@ static int alloc_dinode(struct gfs2_inode *dip, u64 *no_addr, u64 *generation) struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode); int error; - gfs2_alloc_get(dip); + if (gfs2_alloc_get(dip) == NULL) + return -ENOMEM; - dip->i_alloc.al_requested = RES_DINODE; + dip->i_alloc->al_requested = RES_DINODE; error = gfs2_inplace_reserve(dip); if (error) goto out; @@ -900,7 +901,7 @@ fail_end_trans: gfs2_trans_end(sdp); fail_ipreserv: - if (dip->i_alloc.al_rgd) + if (dip->i_alloc->al_rgd) gfs2_inplace_release(dip); fail_quota_locks: -- cgit v1.1