Severe performance degradation with transaction logging enabled.

With logging enabled, e.g.

CONFIG proxy.config.log2.logging_enabled INT 3
CONFIG proxy.config.log2.squid_log_enabled INT 1
CONFIG proxy.config.log2.squid_log_is_ascii INT 0

ATS "trunk" (and "dev" branch) suffers from serious performance degradation over time. I ran a number of tests, each 30s long, fetching a 500 byte long object from cache (ram cache enabled). The tests starts off doing about 20k QPS on my box, but with every iteration, it degrades (more so in the beginning). Within 30 minutes, performance had dropped to 3,800 QPS, at which point the process segfaulted (I think it's a meaningless trace though, but attaching it nonetheless).

The CPU is completely pegged at all times, so it's definitely doing less and less workload, using the same (or more) CPU. I did not observe any memory growth, so I don't think it's a memory leak per se (but could still obviously be related to starving some resource inside TS).