Re: [Xen-devel] [Fwd: [Xen-users] Dom0 and memory]

[Keir Fraser <keir.fraser@xxxxxxxxxxxxx>]

My suspicion would be the dom0 kernel and I'd try a different kernel to see
if that has the same issue. For example, the XCP patch queue (basically
Citrix XenServer's dom0 kernel) which applies on top of a vanilla 2.6.27
source tree: http://xenbits.xen.org/xapi/linux-2.6.27.pq.hg

Basically it looks like the dom0 kernel is voluntarily giving up 900M of
memory, for some reason, even though Xen and tools would like it to have
that memory.

 -- Keir

On 26/06/2010 12:24, "Luís Silva" <luis.silva@xxxxxxxxxxxxx> wrote:

> Hello,
> 
> I posted this email on xen-users a while back and I got no answer. I thought
> it could be a configuration problem and didn't want to cause unnecessary noise
> on xen-devel...
> 
> As no aswers came and I found no documentation supporting this behaviour I'm
> posting now to xen-devel. Xen was updated to 4.0.1-rc3 and the problem stayed
> the same.
> 
> Can anyone help me?
> 
> Thanks,
> Luís
> 
> -------- Forwarded Message --------
>>  From: Luís Silva <luis.silva@xxxxxxxxxxxxx
>> <mailto:%3d%3fISO-8859-1%3fQ%3fLu%3dEDs%3f%3d%20Silva%20%3cluis.silva@axiomas
>> oft.pt%3e> >
>>  Reply-to: luis.silva@xxxxxxxxxxxxx
>>  To: Xen-users@xxxxxxxxxxxxxxxxxxx
>>  Subject: [Xen-users] Dom0 and memory
>>  Date: Sat, 19 Jun 2010 12:01:53 +0100
>>  
>>  Hello,
>>  
>>  I'm trying to use Xen (4.0.1-rc2 with 2.6.32.x paravirt kernel) in a desktop
>> machine. This machine has 4G ram, and xen gets 3884MB available, acording to
>> xm info. Acording to xm list, dom0 gets 3884MB of memory, but dom0 kernel
>> only sees about 2724MB. dom0_mem is unset at boot, but if set at 4G or 3884M
>> the problem remains the same. As this is a desktop machine I would like dom0
>> to have the maximum available memory at boot and then balloon out as
>> necessary. How can I achieve this?
>>  
>>  Thanks in advance,
>>  Luís
>>  
>> 
>> xm info
>> host                   : luis-port
>> release                : 2.6.32.15-1-pvops
>> version                : #5 SMP PREEMPT Wed Jun 16 16:56:00 WEST 2010
>> machine                : x86_64
>> nr_cpus                : 4
>> nr_nodes               : 1
>> cores_per_socket       : 2
>> threads_per_core       : 2
>> cpu_mhz                : 2660
>> hw_caps                :
>> bfebfbff:28100800:00000000:00001f40:0298e3ff:00000000:00000001:00000000
>> virt_caps              : hvm hvm_directio
>> total_memory           : 3884
>> free_memory            : 933
>> node_to_cpu            : node0:0-3
>> node_to_memory         : node0:933
>> node_to_dma32_mem      : node0:861
>> max_node_id            : 0
>> xen_major              : 4
>> xen_minor              : 0
>> xen_extra              : .1-rc2
>> xen_caps               : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32
>> hvm-3.0-x86_32p hvm-3.0-x86_64
>> xen_scheduler          : credit
>> xen_pagesize           : 4096
>> platform_params        : virt_start=0xffff800000000000
>> xen_changeset          : unavailable
>> xen_commandline        :
>> cc_compiler            : gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5)
>> cc_compile_by          : buildd
>> cc_compile_domain      : ppa
>> cc_compile_date        : Thu Jun 10 16:58:29 UTC 2010
>> xend_config_format     : 4
>> 
>> 
=============================================================================>>
=
>> 
>> xm list 
>> Name                                        ID   Mem VCPUs      State
>> Time(s)
>> Domain-0                                     0  3884     4     r-----
>> 771.8
>> srv-001-ub1004                                   256     1
>> 0.0
>> 
>> 
=============================================================================>>
=
>> 
>> xm list -l
>> (domain
>>     (domid 0)
>>     (cpu_weight 256)
>>     (cpu_cap 0)
>>     (bootloader )
>>     (on_crash restart)
>>     (uuid 00000000-0000-0000-0000-000000000000)
>>     (bootloader_args )
>>     (vcpus 4)
>>     (description )
>>     (name Domain-0)
>>     (cpus (() () () ()))
>>     (on_reboot restart)
>>     (on_poweroff destroy)
>>     (maxmem 16777215)
>>     (memory 3884)
>>     (shadow_memory 0)
>>     (features )
>>     (on_xend_start ignore)
>>     (on_xend_stop ignore)
>>     (cpu_time 776.139622245)
>>     (online_vcpus 4)
>>     (image (linux (kernel ) (superpages 0) (nomigrate 0) (tsc_mode 0)))
>>     (status 2)
>>     (state r-----)
>> )
>> (domain
>>     (cpu_weight 256)
>>     (cpu_cap 0)
>>     (bootloader /usr/bin/pygrub)
>>     (on_crash destroy)
>>     (uuid 2d701982-75c1-023b-c1ca-534363463e9e)
>>     (bootloader_args )
>>     (vcpus 1)
>>     (description )
>>     (name srv-001-ub1004)
>>     (cpus (()))
>>     (on_reboot restart)
>>     (on_poweroff destroy)
>>     (maxmem 256)
>>     (memory 256)
>>     (shadow_memory 0)
>>     (features )
>>     (on_xend_start ignore)
>>     (on_xend_stop ignore)
>>     (start_time 1276883490.07)
>>     (image
>>         (linux
>>             (kernel )
>>             (superpages 0)
>>             (pci ())
>>             (nomigrate 0)
>>             (tsc_mode 0)
>>             (device_model /usr/lib/xen/bin/qemu-dm)
>>             (notes
>>                 (HV_START_LOW 18446603336221196288)
>>                 (FEATURES '!writable_page_tables|pae_pgdir_above_4gb')
>>                 (VIRT_BASE 18446744071562067968)
>>                 (GUEST_VERSION 2.6)
>>                 (PADDR_OFFSET 0)
>>                 (GUEST_OS linux)
>>                 (HYPERCALL_PAGE 18446744071578882048)
>>                 (LOADER generic)
>>                 (SUSPEND_CANCEL 1)
>>                 (PAE_MODE yes)
>>                 (ENTRY 18446744071587734016)
>>                 (XEN_VERSION xen-3.0)
>>             )
>>         )
>>     )
>>     (status 0)
>>     (device
>>         (tap2
>>             (protocol x86_64-abi)
>>             (uuid 7d542bc6-8a64-6c06-881f-e03d8bbf75c3)
>>             (bootable 1)
>>             (dev xvda:disk)
>>             (uname
>> tap:tapdisk:aio:/var/lib/libvirt/images/srv-001-ub1004.img)
>>             (mode w)
>>             (backend 0)
>>         )
>>     )
>>     (device
>>         (vif
>>             (bridge virbr0)
>>             (mac 00:16:36:47:57:87)
>>             (backend 0)
>>             (uuid 9682f5ef-382c-1415-3458-516fed1f0a8e)
>>             (script /etc/xen/scripts/vif-bridge)
>>         )
>>     )
>>     (device (vkbd (uuid 0ffbdeb0-5c30-3da6-27de-1724f6a55776) (backend 0)))
>>     (device
>>         (vfb
>>             (vncunused 0)
>>             (vnc 1)
>>             (uuid e7a111fa-8455-a18f-f30f-c0a4970da21b)
>>             (vnclisten 127.0.0.1)
>>             (vncdisplay 1)
>>             (keymap pt)
>>         )
>>     )
>> )
>> 
>> 
=============================================================================>>
=
>> 
>> cat /proc/meminfo
>> MemTotal:        2789504 kB
>> MemFree:           28356 kB
>> Buffers:           12064 kB
>> Cached:           720924 kB
>> SwapCached:         2264 kB
>> Active:          1818904 kB
>> Inactive:         643364 kB
>> Active(anon):    1476156 kB
>> Inactive(anon):   371192 kB
>> Active(file):     342748 kB
>> Inactive(file):   272172 kB
>> Unevictable:          64 kB
>> Mlocked:              64 kB
>> SwapTotal:       3999736 kB
>> SwapFree:        3986772 kB
>> Dirty:                 8 kB
>> Writeback:             0 kB
>> AnonPages:       1727548 kB
>> Mapped:           103612 kB
>> Shmem:            118064 kB
>> Slab:              54860 kB
>> SReclaimable:      26128 kB
>> SUnreclaim:        28732 kB
>> KernelStack:        2768 kB
>> PageTables:        26524 kB
>> NFS_Unstable:          0 kB
>> Bounce:                0 kB
>> WritebackTmp:          0 kB
>> CommitLimit:     5394488 kB
>> Committed_AS:    1820704 kB
>> VmallocTotal:   34359738367 kB
>> VmallocUsed:      560132 kB
>> VmallocChunk:   34359176696 kB
>> HardwareCorrupted:     0 kB
>> HugePages_Total:       0
>> HugePages_Free:        0
>> HugePages_Rsvd:        0
>> HugePages_Surp:        0
>> Hugepagesize:       2048 kB
>> DirectMap4k:     2798464 kB
>> DirectMap2M:           0 kB
>> 
>>  
>> 
>> _______________________________________________
>> Xen-users mailing list
>> Xen-users@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-users
> 
> 



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