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| author | Steven Whitehouse <swhiteho@redhat.com> | 2008-01-10 15:18:55 +0000 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2008-01-25 08:18:25 +0000 |
| commit | 6dbd822487d0a9f14432cb4680415b80656b63a2 (patch) | |
| tree | f0391d598c27cd7c39c67cfa13799a784f4c389a /fs/gfs2/rgrp.c | |
| parent | ac39aadd0440ae696e6dacaa8006ce1737b17008 (diff) | |
| download | lwn-6dbd822487d0a9f14432cb4680415b80656b63a2.tar.gz lwn-6dbd822487d0a9f14432cb4680415b80656b63a2.zip | |
[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 <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/rgrp.c')
| -rw-r--r-- | fs/gfs2/rgrp.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 68c4bf363c46..3552110b2e5f 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -819,11 +819,9 @@ void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd) struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip) { - struct gfs2_alloc *al = &ip->i_alloc; - - /* FIXME: Should assert that the correct locks are held here... */ - memset(al, 0, sizeof(*al)); - return al; + BUG_ON(ip->i_alloc != NULL); + ip->i_alloc = kzalloc(sizeof(struct gfs2_alloc), GFP_KERNEL); + return ip->i_alloc; } /** @@ -1061,7 +1059,7 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) struct inode *inode = NULL; struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct gfs2_rgrpd *rgd, *begin = NULL; - struct gfs2_alloc *al = &ip->i_alloc; + struct gfs2_alloc *al = ip->i_alloc; int flags = LM_FLAG_TRY; int skipped = 0; int loops = 0; @@ -1176,7 +1174,7 @@ out: int gfs2_inplace_reserve_i(struct gfs2_inode *ip, char *file, unsigned int line) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); - struct gfs2_alloc *al = &ip->i_alloc; + struct gfs2_alloc *al = ip->i_alloc; struct inode *inode; int error = 0; u64 last_unlinked = NO_BLOCK; @@ -1222,7 +1220,7 @@ try_again: void gfs2_inplace_release(struct gfs2_inode *ip) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); - struct gfs2_alloc *al = &ip->i_alloc; + struct gfs2_alloc *al = ip->i_alloc; if (gfs2_assert_warn(sdp, al->al_alloced <= al->al_requested) == -1) fs_warn(sdp, "al_alloced = %u, al_requested = %u " @@ -1412,7 +1410,7 @@ static struct gfs2_rgrpd *rgblk_free(struct gfs2_sbd *sdp, u64 bstart, u64 gfs2_alloc_data(struct gfs2_inode *ip) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); - struct gfs2_alloc *al = &ip->i_alloc; + struct gfs2_alloc *al = ip->i_alloc; struct gfs2_rgrpd *rgd = al->al_rgd; u32 goal, blk; u64 block; @@ -1457,7 +1455,7 @@ u64 gfs2_alloc_data(struct gfs2_inode *ip) u64 gfs2_alloc_meta(struct gfs2_inode *ip) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); - struct gfs2_alloc *al = &ip->i_alloc; + struct gfs2_alloc *al = ip->i_alloc; struct gfs2_rgrpd *rgd = al->al_rgd; u32 goal, blk; u64 block; @@ -1503,7 +1501,7 @@ u64 gfs2_alloc_meta(struct gfs2_inode *ip) u64 gfs2_alloc_di(struct gfs2_inode *dip, u64 *generation) { struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode); - struct gfs2_alloc *al = &dip->i_alloc; + struct gfs2_alloc *al = dip->i_alloc; struct gfs2_rgrpd *rgd = al->al_rgd; u32 blk; u64 block; |