avoid contending on single process-wide precompiled regexes #37
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precompiling the `Regex` instances is good! but being behind `lazy_static!` means all threads are contending an implicit futex somewhere in the lazy_static implementation. on a 32-core system with 32 logs to process in parallel, this ends up with the top symbol in `perf stat` to be something in `futex` and an awful lot of total time waiting on _system stuff_ for no apparent reason. having set of Regex bundles per-thread keeps contention down at the cost of a bit more init on the multi-processor case, but overall at least on my system brings a 31-file benchmark down from 4.6 seconds to about 2.2 seconds.
no reason to limit to 128k really, probably not a big deal either way
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precompiling the
Regexinstances is good! but being behindlazy_static!means all threads are contending an implicit futexsomewhere in the lazy_static implementation. on a 32-core system with 32
logs to process in parallel, this ends up with the top symbol in
perf statto be something infutexand an awful lot of total timewaiting on system stuff for no apparent reason.
having set of Regex bundles per-thread keeps contention down at the
cost of a bit more init on the multi-processor case, but overall at
least on my system brings a 31-file benchmark down from 4.6 seconds to
about 2.2 seconds.
i included a bonus second change to make the read buffers a bit larger but that's not nearly as useful