From: Vladimir Zidar <mr_w@mindnever.org>
To: xen-devel@lists.xensource.com
Subject: hypervisor memory usage
Date: Wed, 28 Oct 2009 10:29:37 +0100 [thread overview]
Message-ID: <4AE80F01.1090602@mindnever.org> (raw)
Hi,
** I sent this mail originally to xen-users, but after seeing other
subjects posted on that list I felt that it was kind of wrong place to
ask **
I'm wondering why hypervisor itself uses so much memory? Is it normal?
I have several servers with 8GB of ram, all of them running x86_64
centos 5.4 (latest) and when running under xen, dom0 has
[root@palmae ~]# head -4 /proc/meminfo
MemTotal: 7661568 kB
MemFree: 6550044 kB
Buffers: 37400 kB
Cached: 303480 kB
Which is 440MB less than what I get without xen.
It comes down to what amount of memory kernel gets either from Xen or
from BIOS. Please note the differences:
when run under xen:
BIOS-provided physical RAM map:
Xen: 0000000000000000 - 00000001dc25c000 (usable)
On node 0 totalpages: 1950300
and just bare metal linux:
BIOS-provided physical RAM map:
BIOS-e820: 0000000000010000 - 000000000009ec00 (usable)
BIOS-e820: 000000000009ec00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000bf780000 (usable)
BIOS-e820: 00000000bf780000 - 00000000bf78e000 (ACPI data)
BIOS-e820: 00000000bf78e000 - 00000000bf7d0000 (ACPI NVS)
BIOS-e820: 00000000bf7d0000 - 00000000bf7e0000 (reserved)
BIOS-e820: 00000000bf7ec000 - 00000000c0000000 (reserved)
BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
BIOS-e820: 00000000ffc00000 - 0000000100000000 (reserved)
BIOS-e820: 0000000100000000 - 0000000240000000 (usable)
DMI present.
ACPI: RSDP (v000 ACPIAM ) @
0x00000000000fa460
ACPI: RSDT (v001 7522MS A7522800 0x20090903 MSFT 0x00000097) @
0x00000000bf780000
ACPI: FADT (v001 7522MS A7522800 0x20090903 MSFT 0x00000097) @
0x00000000bf780200
ACPI: MADT (v001 7522MS A7522800 0x20090903 MSFT 0x00000097) @
0x00000000bf780390
ACPI: MCFG (v001 7522MS OEMMCFG 0x20090903 MSFT 0x00000097) @
0x00000000bf780440
ACPI: OEMB (v001 7522MS A7522800 0x20090903 MSFT 0x00000097) @
0x00000000bf78e040
ACPI: HPET (v001 7522MS OEMHPET 0x20090903 MSFT 0x00000097) @
0x00000000bf78a480
ACPI: SSDT (v001 DpgPmm CpuPm 0x00000012 INTL 0x20051117) @
0x00000000bf790350
ACPI: DSDT (v001 A7522 A7522800 0x00000800 INTL 0x20051117) @
0x0000000000000000
No NUMA configuration found
Faking a node at 0000000000000000-0000000240000000
Bootmem setup node 0 0000000000000000-0000000240000000
Memory for crash kernel (0x0 to 0x0) notwithin permissible range
disabling kdump
On node 0 totalpages: 2061313
That is around 440MB.. It just doesn't seem normal to me? Anything to be
tuned or checked or changed?
Kind Regards,
Vladimir
PS, I apologize if this was asked more than 10 times, but I haven't been
able to google it out (poor choice of keywords maybe).
next reply other threads:[~2009-10-28 9:29 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-28 9:29 Vladimir Zidar [this message]
2009-10-28 9:45 ` hypervisor memory usage Pasi Kärkkäinen
2009-10-28 9:53 ` Vladimir Zidar
2009-10-28 10:40 ` Keir Fraser
2009-10-28 11:19 ` Vladimir Zidar
2009-10-28 11:58 ` Pasi Kärkkäinen
2009-10-28 12:02 ` Vladimir Zidar
2009-10-28 13:12 ` Pasi Kärkkäinen
2009-10-28 13:18 ` Chris Lalancette
2009-10-28 14:13 ` Vladimir Zidar
2009-10-29 11:07 ` Vladimir Zidar
2009-10-29 11:19 ` Vladimir Zidar
2009-10-29 12:05 ` Keir Fraser
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