Anton recently removed SLAB_HWCACHE_ALIGN from the fs inode caches, now do the
same for tmpfs inode cache: fits 9 per page where 7 before.

Was saying SLAB_RECLAIM_ACCOUNT too, but that's wrong: tmpfs inodes are not
reclaimed under pressure; and hugetlbfs had copied that too.

Rearrange shmem_inode_info fields so those most likely to be needed are most
likely to be in the same cacheline as the spinlock guarding them.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>