Messages in this thread | | | Date | Tue, 25 Jun 2013 09:38:19 +0200 | From | Ingo Molnar <> | Subject | Re: [RFC 2/2] x86_64, mm: Reinsert the absent memory |
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* Nathan Zimmer <nzimmer@sgi.com> wrote:
> On Sun, Jun 23, 2013 at 11:28:40AM +0200, Ingo Molnar wrote: > > > > That's 4.5 GB/sec initialization speed - that feels a bit slow and the > > boot time effect should be felt on smaller 'a couple of gigabytes' > > desktop boxes as well. Do we know exactly where the 2 hours of boot > > time on a 32 TB system is spent? > > There are other several spots that could be improved on a large system > but memory initialization is by far the biggest.
My feeling is that deferred/on-demand initialization triggered from the buddy allocator is the better long term solution.
That will also make it much easier to profile/test memory init performance: boot up a large system and run a simple testprogram that allocates a lot of RAM.
( It will also make people want to optimize the initialization sequence better, as it will be part of any freshly booted system's memory allocation overhead. )
Thanks,
Ingo
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