Messages in this thread | | | Date | Sun, 23 Jun 2013 11:32:50 +0200 | From | Ingo Molnar <> | Subject | Re: [RFC 2/2] x86_64, mm: Reinsert the absent memory |
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* Ingo Molnar <mingo@kernel.org> wrote:
> Yet another thing to consider would be to implement an initialization > speedup of 3 orders of magnitude: initialize on the large page (2MB) > grandularity and on-demand delay the initialization of the 4K granular > struct pages [but still allocating them] - which I suspect are a good > chunk of the overhead? That way we could initialize in 2MB steps and speed > up the 2 hours bootup of 32 TB of RAM to 14 seconds... > > [ The cost would be one more branch in the buddy allocator, to detect > not-yet-initialized 2 MB chunks as we encounter them. Acceptable I > think. ]
One advantage of this scheme would be that we could use it on pretty much any box, it would provide instant boot time speedups everywhere [a couple of hundred msecs on a small 4GB box - significant I think] - and would spread out and parallelize initialization to later stages.
Thanks,
Ingo
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