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On Thursday, November 05, 2015 01:34:02 PM hw wrote: |
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> J. Roeleveld wrote: |
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> > On 4 November 2015 13:14:18 CET, hw <hw@×××××.de> wrote: |
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> >> Hi, |
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> >> |
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> >> how do I know whether xen uses NUMA or not? It says in dmesg: |
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> >> |
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> >> |
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> >> [ 0.000000] NUMA turned off |
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> >> [ 0.000000] Faking a node at [mem |
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> >> 0x0000000000000000-0x0000000040068fff] |
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> >> |
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> >> |
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> >> and 'xl info -n' shows two nodes: |
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> >> |
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> >> |
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> >> node: memsize memfree distances |
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> >> |
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> >> 0: 14656 3304 10,20 |
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> >> 1: 23424 7792 20,10 |
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> >> |
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> >> which could be right --- though I would expect each node to have 12GB |
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> >> rather than these weird sizes. |
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> >> |
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> >> So is NUMA turned off or not? Is it even possible to turn it off when |
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> >> it's |
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> >> enabled in the BIOS? |
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> > |
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> > If BIOS has it enabled. Then the OS still beeds to support it. |
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> > |
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> > Recent Xen has support for it. |
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> |
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> Is there any way to find out if it's actually made use of? |
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|
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Yes, you might want to read the Xen documentation: |
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http://wiki.xen.org/wiki/Xen_on_NUMA_Machines |
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> > As for the non uniform spread of the memory. It depends how the memory |
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> > modules are placed in the mainboard with regards to the Numa nodes. (CPU) |
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> The memory is evenly spread. The server has two CPUs with 6 memory banks |
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> each. All banks for each CPU are loaded identically. Hence two NUMA nodes |
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> would make sense, and each of them should see/have 12GB (now 14 each |
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> because I changed out the server because it kept crashing/freezing/becoming |
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> unreachable even after the software updates). |
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|
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Is this according to the actual manual? Or based on what the mainboard looks |
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like? |
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|
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-- |
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