[Cbe-oss-dev] (no subject)

[Geoff Levand]

Clint Thomas wrote:
> Hey guys,
> 
> I was wondering how much memory does the Hypervisor take off the top end of system memory? 

For the PS3, that information has not been disclosed.

No matter what linux distribution I install, the most system memory I can have available is between 201 to 203 MB. One explanation I have heard is that a combination of per-page mapping memory loss and hypervisor virtualization are responsible, but I would like some clarification. Thanks

I think there are several questions here all mixed together.

First the amount available to the other os lpar.  That can be
seen with the patch below applied to a recent kernel.

 -> ps3_mm_init:1200
ps3_mm_region_create:249 requested  7800000h
ps3_mm_region_create:250 actual     7000000h
ps3_mm_region_create:251 difference 800000h (8MB)
 <- ps3_mm_init:1223
ps3_mm_vas_create:202: map.total     = f000000h
ps3_mm_vas_create:202: map.rm.size   = 8000000h
ps3_mm_vas_create:202: map.vas_id    = 11
ps3_mm_vas_create:202: map.htab_size = 100000h
ps3_mm_vas_create:202: map.r1.base   = 6c0060000000h
ps3_mm_vas_create:202: map.r1.offset = 6c0058000000h
ps3_mm_vas_create:202: map.r1.size   = 7000000h
PS3 firmware version 1.8.0
ps3fb videomemory: 18874368 bytes at c000000000800000
ps3flash bounce buffer: 262144 bytes at c000000000780000

fire-nfs:~# cat /proc/meminfo
MemTotal:       219324 kB
MemFree:         95804 kB

So this shows f000000h = 240 MiB total RAM available to
the OS running in the other OS lpar.

Then linux needs some memory to run and that is subtracted
to get 219324 kB here. 18874368 bytes are for video frambuffer,
and 262144 bytes are for the flash memory driver.

-Geoff


--- a/arch/powerpc/platforms/ps3/mm.c
+++ b/arch/powerpc/platforms/ps3/mm.c
@@ -17,7 +17,7 @@
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
-
+#define DEBUG
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/memory_hotplug.h>
@@ -30,7 +30,7 @@
 #include "platform.h"
 
 #if defined(DEBUG)
-#define DBG udbg_printf
+#define DBG printk
 #else
 #define DBG pr_debug
 #endif