[XFS] Pick a single default inode cluster size.

Remove scaling of inode "clusters" based on machine memory; small cluster
cut-point was an unrealistic 32MB and was probably never tested.

Removes another user of xfs_physmem.

SGI-PV: 968563
SGI-Modid: xfs-linux-melb:xfs-kern:29324a
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NTim Shimmin <tes@sgi.com>

fs/xfs/xfs_ialloc.h

@@ -30,14 +30,9 @@ struct xfs_trans;
 #define	XFS_IALLOC_BLOCKS(mp)	(mp)->m_ialloc_blks
 
 /*
- * For small block file systems, move inodes in clusters of this size.
- * When we don't have a lot of memory, however, we go a bit smaller
- * to reduce the number of AGI and ialloc btree blocks we need to keep
- * around for xfs_dilocate().  We choose which one to use in
- * xfs_mount_int().
+ * Move inodes in clusters of this size.
  */
 #define	XFS_INODE_BIG_CLUSTER_SIZE	8192
-#define	XFS_INODE_SMALL_CLUSTER_SIZE	4096
 #define	XFS_INODE_CLUSTER_SIZE(mp)	(mp)->m_inode_cluster_size
 
 /*

fs/xfs/xfs_mount.c

@@ -885,15 +885,12 @@ xfs_mountfs(
 	mp->m_writeio_blocks = 1 << (mp->m_writeio_log - sbp->sb_blocklog);
 
 	/*
-	 * Set the inode cluster size based on the physical memory
-	 * size.  This may still be overridden by the file system
+	 * Set the inode cluster size.
+	 * This may still be overridden by the file system
 	 * block size if it is larger than the chosen cluster size.
 	 */
-	if (xfs_physmem <= btoc(32 * 1024 * 1024)) { /* <= 32 MB */
-		mp->m_inode_cluster_size = XFS_INODE_SMALL_CLUSTER_SIZE;
-	} else {
 	mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE;
-	}
+
 	/*
 	 * Set whether we're using inode alignment.
 	 */