mkfs.xfs cannot make sector size 64 KiB?

[Justin Piszcz <jpiszcz@xxxxxxxxxxxxxxx>]

From the manpage:

       -b     Block size options.

              This option specifies the fundamental block size of the filesys-
              tem.   The  valid suboptions are: log=value and size=value; only
              one can be supplied.  The block size is specified  either  as  a
              base two logarithm value with log=, or in bytes with size=.  The
              default value is 4096 bytes (4 KiB), the minimum is 512, and the
              maximum is 65536 (64 KiB).  XFS on Linux currently only supports
              pagesize or smaller blocks.

The maximum size is 64 KiB, yet it seems only up to 32 KiB is valid?

I am running x86_64.

$ uname -m
x86_64


p34:~# mkfs.xfs -b size=512 /dev/md3
mkfs.xfs: /dev/md3 appears to contain an existing filesystem (xfs).
mkfs.xfs: Use the -f option to force overwrite.
p34:~# mkfs.xfs -b size=4096 /dev/md3
mkfs.xfs: /dev/md3 appears to contain an existing filesystem (xfs).
mkfs.xfs: Use the -f option to force overwrite.
p34:~# mkfs.xfs -b size=8192 /dev/md3
mkfs.xfs: /dev/md3 appears to contain an existing filesystem (xfs).
mkfs.xfs: Use the -f option to force overwrite.
p34:~# mkfs.xfs -b size=16384 /dev/md3
mkfs.xfs: /dev/md3 appears to contain an existing filesystem (xfs).
mkfs.xfs: Use the -f option to force overwrite.
p34:~# mkfs.xfs -b size=32768 /dev/md3
mkfs.xfs: /dev/md3 appears to contain an existing filesystem (xfs).
mkfs.xfs: Use the -f option to force overwrite.
p34:~# mkfs.xfs -b size=65536 /dev/md3
illegal sector size 65536
Usage: mkfs.xfs
/* blocksize */         [-b log=n|size=num]
/* data subvol */       [-d agcount=n,agsize=n,file,name=xxx,size=num,
                            (sunit=value,swidth=value|su=num,sw=num),
                            sectlog=n|sectsize=num,unwritten=0|1]
/* inode size */        [-i log=n|perblock=n|size=num,maxpct=n,attr=0|1|2]
/* log subvol */        [-l agnum=n,internal,size=num,logdev=xxx,version=n
                            sunit=value|su=num,sectlog=n|sectsize=num]
/* label */             [-L label (maximum 12 characters)]
/* naming */            [-n log=n|size=num,version=n]
/* prototype file */    [-p fname]
/* quiet */             [-q]
/* realtime subvol */   [-r extsize=num,size=num,rtdev=xxx]
/* sectorsize */        [-s log=n|size=num]
/* version */           [-V]
                        devicename
<devicename> is required unless -d name=xxx is given.
<num> is xxx (bytes), xxxs (sectors), xxxb (fs blocks), xxxk (xxx KiB),
      xxxm (xxx MiB), xxxg (xxx GiB), xxxt (xxx TiB) or xxxp (xxx PiB).
<value> is xxx (512 byte blocks).
p34:~#

Unless, the page size is not <= 64 for x86_64?

Justin.