cmcfarlen opened a new pull request, #13992:
URL: https://github.com/apache/trafficserver/pull/13992
`url_mapping::_hitCount` is a `std::atomic<uint64_t>` on the remap rule,
which every thread shares. Each remapped request increments it from whatever
thread it runs on, so the cache line holding it bounces between cores. That
line also holds members read per request, like the plugin instance list
`run_single_remap` walks, so those reads miss too. On an H2 cache-hit benchmark
at 32 threads, this line was about 4% of perf c2c HITMs.
The value is never read. Its only reader was the `{stat}` `remap_hits` page,
which was removed in #10710. This removes the counter, the `remapKey` string
kept only to label it, and the `PrintRemapHit*` dump helpers that nothing calls.
No behavior change: this only deletes code.
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