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- From: Aaron Knoll <
>
- To:
- Subject: [Manta] Re: Re: Re: Re: parallel bvh
- Date: Tue, 8 Mar 2011 20:02:34 -0600
Sounds pretty typical for most algorithms that run "at scale" :P
On Mar 8, 2011, at 7:57 PM, Carson wrote:
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it scales well, unfortunately for a 50MB file it was allocating over 10
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GB of memory and is getting a 20th the runtime performance.
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Carson
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>
On Tue, 2011-03-08 at 15:46 -0800, Solomon Boulos wrote:
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> The problem is that my hacked-together task system allocates a ton of
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> memory for all the parallel build tasks. If you were to actually want to
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> use it, you'd want to create a memory pool for those tasks so that you can
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> create and destroy them efficiently (and from multiple threads). Other
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> than that it's sort of okay (as you can see from the reasonable-ish build).
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>
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> Ultimately though, if you compared to the lazy build code (which Thiago
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> reports as being busted now) you'd have pretty similar speedups without
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> hassles (the only issue being that it's easy to do subtree parallelism
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> with a lazy build, but hard to cooperate with the root-node construction
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> which this code does).
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>
>
> Anyway, glad to see it still works 4 years later.
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>
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> On Mar 8, 2011, at 3:42 PM, Carson wrote:
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>
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>> timings for dynBVH parallel build on 4-core nehalem.
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>>
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>> dragon model: 0.87 million tri
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>>
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>> np seconds speedup efficiency
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>> 1: 1.08881 1 1
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>> 2: 0.594981 1.83 .915
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>> 3: 0.416616 2.57 .86
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>> 4: 0.346193 3.12 .78
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>> 8: 0.268632 4.01 0.5
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>>
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>> Carson
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>>
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>> On Tue, 2011-03-08 at 15:26 -0700, Thiago Ize wrote:
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>>> I don't really want to go through the hassle of getting the parallel
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>>> code up and running only to then realize it's no good and remove it
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>>> all. Easiest might be to revert to the previous version and then modify
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>>> DynBVH.h so that computeBounds is
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>>>
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>>> void computeBounds(const PreprocessContext& context,
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>>> BBox& bbox) const
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>>> {
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>>> currGroup->computeBounds(context, bbox);
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>>> }
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>>>
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>>> That should hopefully do the trick and take you less than a minute to
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>>> find out. Let me know if that still doesn't work.
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>>>
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>>> Carson wrote:
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>>>> it's now crashing with the recent changes I'll need to spend some time
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>>>> debugging it. Maybe later tonight.
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>>>> Carson
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>>>>
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>>>>
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