Our test server (Unisys ES7000) has recently been upgraded
with more processors and more memory, so I am testing x86_64 xen with 64 cpus
and 192gb.  I compiled xen with max_phys_cpus=64 and debug=y.  xen sees
the 64 cpus, but only sees 173800500k of the 192gb.  I booted dom0 with
2048M and numa=on.  I get the same result when I configure the server to
have 176gb (xen still sees only 173800500k). Booting without numa=on makes no
difference.
 
xentop - 14:48:42   Xen 3.0-unstable
1 domains: 1 running, 0 blocked, 0 paused, 0 crashed, 0 dying, 0
shutdown
Mem: 173800500k total, 4324748k used, 169475752k free   
CPUs: 64 @ 3400MHz
      NAME  STATE  
CPU(sec) CPU(%)     MEM(k) MEM(%)  MAXMEM(k) MAXMEM(%)
VCPUS
 NETS NETTX(k) NETRX(k) VBDS   VBD_OO  
VBD_RD   VBD_WR SSID
  Domain-0 -----r        
95    0.0    2097152   
1.2   no limit      
n/a    32
    0       
0        0   
0       
0       
0        0    0
 
When I configure the server with 160gb or less, xen sees all
of the memory. 
 
Also, when I boot with the SLES kernel, SLES can see the all
of the memory.
 
I assume there is not a memory limit on xen.  I would
greatly appreciate any help to resolve this problem.
 
Thanks,
Sue Krysan
Linux Systems Group
Unisys Corporation