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tesseract-robotics / trajopt

Trajectory Optimization Motion Planner for ROS
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Remove unneeded reserve() calls #391

Closed rjoomen closed 7 months ago

rjoomen commented 7 months ago

In expr_ops.hpp reserve() was called at every variable update. This causes the variable and coefficient vectors to be relocated very often, as their size is updated by a minimal amount every time . Removing the reserve() calls allows the vectors to use their normal growing behavior, improving performance.

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rjoomen commented 7 months ago

I'm not sure. Do you know what size the coeff and var vectors typically are? The normal automatic vector reserve growing behavior is by a fixed factor of 1.5, so in the worst case we only use 1.5 times the amount of memory compared to the current situation.

Levi-Armstrong commented 7 months ago

I will run heaptrack in the near future.

rjoomen commented 7 months ago

I just read that a shrink_to_fit can also cause a reallocation. So unless we really need the memory it's not advisable to use it.