[RFC] Insert right objects before the left ones #152
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…ss remaining siblings When we found where we should be inserted, we have to look at next sibling in case they should become children. No need to go till the last children: Once the first cpuset bit of a children is above out last, we're done. Mostly useful when inserting in reverse-cpuset-order.
…creation time The core inserts new objects within children by walking the existing children list from left to right. So insert the left children last is more efficient since it doesn't walk the entire list anymore. Otherwise, the overall complexity is quadratic with the number of children below objects. lstopo -i "pu:10000" goes down from 20s to 0.8s on my laptop. lstopo -i "100 100" is only improved by 1-2%. On real/existing platforms (KNL or 768pu-AltixUV), the impact seems negligible.
bgoglin
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Not really useful as long as we don't have hundreds of children within a single object. The quadratic complexity is negligible on current machines since we usually have tens of children max. Mostly useful for large synthetic topologies so far.
Check whether the first commit in the PR decreases performance before merging.
Otherwise just keep that code here until machines really need that sort of optimization. The Linux backend will need a reverse foreach loop.