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

To: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Subject: Re: [Xen-devel] [Fwd: [Xen-users] Dom0 and memory]
From: Luís Silva <luis.silva@xxxxxxxxxxxxx>
Date: Sun, 27 Jun 2010 00:44:34 +0100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
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Hello Jeremy,

Attached follows both dmesg and xm dmesg.

Strange that dom0 is freeing the memory at boot time... I just have one VM configured (that doesn't even boot automatically) and it only has 512MB (it was 256MB when I sent the first message) of memory allocated to it.
Is this supposed to happen, can it be controlled with any configuration?

Please note that now my boot parameters for xen kernel are "dom0_mem=min:3G,max:4G", but they already were "dom0_mem=4G", "dom0_mem=3884M" and none at all and the result was the same.

Just ask if you need anything else.

Thanks,
Luís

On Sat, 2010-06-26 at 17:09 +0100, Jeremy Fitzhardinge wrote:
On 06/26/2010 12:24 PM, Luís Silva 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.

Does the boot log show the kernel releasing some memory back to Xen?

>
> 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@xxxxxxxxxxxxx%3e>>
>> *Reply-to*: luis.silva@xxxxxxxxxxxxx
>> *To*: Xen-users@xxxxxxxxxxxxxxxxxxx
>> <mailto: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_directioit
>> total_memory           : 3884
>> free_memory            : 933
>>     

It looks like it has.

>> 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
>>     

Could you post the full dom0 boot log?

    J

>> 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 <mailto:Xen-users@xxxxxxxxxxxxxxxxxxx>
>> http://lists.xensource.com/xen-users
>>     
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
>   



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