Get rid of permutation table in dynamic Maglev #24
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Fixes #18
This change gets rid of the huge permutation table. It turns out that the necessary values can be computed just as fast on the fly: there's no need to retrieve them from memory.
Another modification is that nfqlb (de)activate computes the new lookup table in a temporary array and copies the results to the actual lookup table in shared memory only when the Maglev computation is done: this makes sure that the loadbalancer does not throw away packets while Maglev computation is taking place.
This PR changes only the dynamic Maglev computation: the static Maglev parts (which are used only for reference) still use the old permutation table-based method.
Attached is a graph about the overall speedup achieved in the populate function. The proposed new method creates an equivalent lookup table.
![speedup](https://private-user-images.githubusercontent.com/172371296/338561255-76e4cf22-dd0d-4f9e-b022-4db5d8d15194.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJnaXRodWIuY29tIiwiYXVkIjoicmF3LmdpdGh1YnVzZXJjb250ZW50LmNvbSIsImtleSI6ImtleTUiLCJleHAiOjE3MjUyMTAzOTIsIm5iZiI6MTcyNTIxMDA5MiwicGF0aCI6Ii8xNzIzNzEyOTYvMzM4NTYxMjU1LTc2ZTRjZjIyLWRkMGQtNGY5ZS1iMDIyLTRkYjVkOGQxNTE5NC5wbmc_WC1BbXotQWxnb3JpdGhtPUFXUzQtSE1BQy1TSEEyNTYmWC1BbXotQ3JlZGVudGlhbD1BS0lBVkNPRFlMU0E1M1BRSzRaQSUyRjIwMjQwOTAxJTJGdXMtZWFzdC0xJTJGczMlMkZhd3M0X3JlcXVlc3QmWC1BbXotRGF0ZT0yMDI0MDkwMVQxNzAxMzJaJlgtQW16LUV4cGlyZXM9MzAwJlgtQW16LVNpZ25hdHVyZT04MDA0ODU3YWRkMjFkNDRkYjdmNzQ5ZWExY2E5Y2VhNzAyYTk3ZmUzOGZmYWY2NjVlN2UwNWU1MWY4MDI4NDM5JlgtQW16LVNpZ25lZEhlYWRlcnM9aG9zdCZhY3Rvcl9pZD0wJmtleV9pZD0wJnJlcG9faWQ9MCJ9.GxqI2LuOZWW6UkMyTOc87WYG5JWSppcPpFfunppxom4)
As you see, the new method is faster until we have about 60 targets or so.