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> Something _really_ weird happened to your quoting; you quoted my |
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> email, but your email client said you wrote it. |
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> |
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> On Mon, Dec 17, 2012 at 2:00 AM, J. Roeleveld <joost@××××××××.org> wrote: |
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>>> On Sun, Dec 16, 2012 at 10:39 AM, J. Roeleveld <joost@××××××××.org> |
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>>> wrote: |
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> |
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> ^-- weird --^ |
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|
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Very weird, especially as I am using the same client now (squirrelmail) |
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and I don't see that line at all now. |
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|
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>>>> On Sunday, December 16, 2012 01:52:46 PM Volker Armin Hemmann wrote: |
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>>>>> Am Samstag, 15. Dezember 2012, 20:57:24 schrieb J. Roeleveld: |
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>>>>> > Even on a system with only 2 sockets, it can be useful to have NUMA |
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>>>>> > available. |
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>>>>> |
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>>>>> or not, because it costs you performance. |
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>>>> |
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>>>> When does it cost performance? |
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>>>> In all situations? |
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>>> |
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>>> It adds some additional logic to memory allocation (put an allocation |
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>>> near the process that uses it) and to process scheduling (keep the |
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>>> process near its memory, but bump it to a more distant idle core if |
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>>> necessary). |
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>> |
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>> That's the way it's supposed to work, yes :) |
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>> |
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>>> In all honestly, it's not a performance loss you're likely to notice, |
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>>> unless you're so in need of squeezing out every spare cycle that you |
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>>> most definitely _have_ hardware where there are disconnected memory |
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>>> banks. I'm not convinced it's even measurable for us mundanes and our |
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>>> hardware. |
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>> |
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>> I don't think I would notice it either, but as the system I have |
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>> supports |
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>> it, I want to use it. |
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>> And then I want to be certain it actually supports it correctly. |
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>> |
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>> The system I'm talking about is used for testing purposes. Running |
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>> multiple VMs. As far as I know, Xen has support for it, just need to |
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>> configure it properly. |
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>> And for this usecase, I think NUMA with only 2 physical CPUs should make |
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>> a |
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>> positive difference. |
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> |
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> Don't get me wrong; I was arguing that it shouldn't hurt to have it |
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> enabled. :) |
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|
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I know, just wanted to add the use-case for considering NUMA a usefull |
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option even with only 2 physical CPUs :) |
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|
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-- |
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Joost |
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