[pve-devel] CPU and Memory hot add

[Stefan Priebe]

Am 15.02.2014 13:59, schrieb Alexandre DERUMIER:
> cpu hot add is already implemented. (even in proxmox ;)
> https://git.proxmox.com/?p=qemu-server.git;a=commit;h=838776ab650f0593b48c234070c1a189fdbd72c7
>
> cpu hot del is not yet implemented. (but they are some prelimary patches in the qemu mailing list)
>
> memory hotplug is not yet implemented. (should be ok for next qemu 2.0 release I think)
>
> But maybe they are cheating, like I do : just use ballonning with a fixed size ?

No they don't ;-) here an output of a running vm adding more memory:

[  356.984360] Hotplug Mem Device
[  356.985973] init_memory_mapping: 0000000040000000-0000000080000000
[  356.986070]  0040000000 - 0080000000 page 1G
[  356.988604]  [ffffea0001000000-ffffea00011fffff] PMD -> 
[ffff88003ce00000-ffff88003cffffff] on node 0
[  356.997027]  [ffffea0001200000-ffffea00013fffff] PMD -> 
[ffff88003c800000-ffff88003c9fffff] on node 0
[  356.998495]  [ffffea0001400000-ffffea00015fffff] PMD -> 
[ffff88003c600000-ffff88003c7fffff] on node 0
[  357.000084]  [ffffea0001600000-ffffea00017fffff] PMD -> 
[ffff88003b000000-ffff88003b1fffff] on node 0
[  357.001459]  [ffffea0001800000-ffffea00019fffff] PMD -> 
[ffff880034c00000-ffff880034dfffff] on node 0
[  357.004401]  [ffffea0001a00000-ffffea0001dfffff] PMD -> 
[ffff88003c000000-ffff88003c3fffff] on node 0
[  357.007038] Hotplug Mem Device
[  357.024941] Built 1 zonelists in Node order, mobility grouping on. 
Total pages: 273785
[  357.024941] Policy zone: Normal
[  357.038623] init_memory_mapping: 0000000080000000-00000000c0000000
[  357.038636]  0080000000 - 00c0000000 page 1G
[  357.038782]  [ffffea0001e00000-ffffea0001ffffff] PMD -> 
[ffff88003b400000-ffff88003b5fffff] on node 0
[  357.040088]  [ffffea0002000000-ffffea00021fffff] PMD -> 
[ffff880047e00000-ffff880047ffffff] on node 0
[  357.040756]  [ffffea0002200000-ffffea00025fffff] PMD -> 
[ffff88007fc00000-ffff88007fffffff] on node 0
[  357.044036]  [ffffea0002600000-ffffea00029fffff] PMD -> 
[ffff88007f800000-ffff88007fbfffff] on node 0
[  357.062995]  [ffffea0002a00000-ffffea0002dfffff] PMD -> 
[ffff88007f400000-ffff88007f7fffff] on node 0
[  357.072594] Hotplug Mem Device
[  357.119388] init_memory_mapping: 0000000100000000-0000000140000000
[  357.119388]  0100000000 - 0140000000 page 1G
[  357.121941]  [ffffea0002e00000-ffffea00041fffff] PMD -> 
[ffff88007f000000-ffff88007f3fffff] on node 0
[  357.125199]  [ffffea0004200000-ffffea00045fffff] PMD -> 
[ffff880087800000-ffff880087bfffff] on node 0
[  357.128890]  [ffffea0004600000-ffffea00049fffff] PMD -> 
[ffff880087400000-ffff8800877fffff] on node 0
[  357.132014]  [ffffea0004a00000-ffffea0004dfffff] PMD -> 
[ffff880087000000-ffff8800873fffff] on node 0
[  357.135378] Hotplug Mem Device
[  357.170010] init_memory_mapping: 0000000140000000-0000000180000000
[  357.170010]  0140000000 - 0180000000 page 1G
[  357.170174]  [ffffea0004e00000-ffffea00051fffff] PMD -> 
[ffff880086c00000-ffff880086ffffff] on node 0
[  357.172473]  [ffffea0005200000-ffffea00055fffff] PMD -> 
[ffff880127c00000-ffff880127ffffff] on node 0
[  357.175795]  [ffffea0005600000-ffffea00059fffff] PMD -> 
[ffff880127800000-ffff880127bfffff] on node 0
[  357.180010]  [ffffea0005a00000-ffffea0005dfffff] PMD -> 
[ffff880127400000-ffff8801277fffff] on node 0
[  357.195142] Hotplug Mem Device
[  357.195409] init_memory_mapping: 0000000180000000-00000001c0000000
[  357.195409]  0180000000 - 01c0000000 page 1G
[  357.197770]  [ffffea0005e00000-ffffea00061fffff] PMD -> 
[ffff880127000000-ffff8801273fffff] on node 0
[  357.199525]  [ffffea0006200000-ffffea00063fffff] PMD -> 
[ffff880137e00000-ffff880137ffffff] on node 0
[  357.202982]  [ffffea0006400000-ffffea00067fffff] PMD -> 
[ffff880137800000-ffff880137bfffff] on node 0
[  357.206225]  [ffffea0006800000-ffffea0006bfffff] PMD -> 
[ffff880137400000-ffff8801377fffff] on node 0
[  357.210314] Hotplug Mem Device
[  357.280089] init_memory_mapping: 00000001c0000000-0000000200000000
[  357.280089]  01c0000000 - 0200000000 page 1G
[  357.280295]  [ffffea0006c00000-ffffea0006ffffff] PMD -> 
[ffff880137000000-ffff8801373fffff] on node 0
[  357.280898]  [ffffea0007000000-ffffea00073fffff] PMD -> 
[ffff8801b7c00000-ffff8801b7ffffff] on node 0
[  357.284138]  [ffffea0007400000-ffffea00077fffff] PMD -> 
[ffff8801b7800000-ffff8801b7bfffff] on node 0
[  357.290084]  [ffffea0007800000-ffffea0007bfffff] PMD -> 
[ffff8801b7400000-ffff8801b77fffff] on node 0

Stefan

>
> ----- Mail original -----
>
> De: "Stefan Priebe" <s.priebe at profihost.ag>
> À: pve-devel at pve.proxmox.com
> Envoyé: Vendredi 14 Février 2014 21:18:47
> Objet: [pve-devel] CPU and Memory hot add
>
> Hi,
>
> while browsing the web, i found profitbricks, which is active in germany
> and the us (http://www.profitbricks.com/technical-info).
>
> They use KVM and offer memory and cpu hot add on the fly? Anybody an
> idea how this works if kvm does not already support it?
>
> Greets,
> Stefan
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