10.1 is 3% slower than 10.0 in OLTP RO

Even though 10.1 has quite a few generic optimizations it still shows slightly worse performance compared to 10.0. This trend can be reproduced quite reliably on different platforms (10.0 -> 10.1):

1 thread avg TPS: 805.91 -> 780.83 (3.11%)

1 thread max TPS: 810.60 -> 788.50 (2.73%)

64 threads avg TPS: 23026.92 -> 22346.58 (2.95%)

64 threads max TPS: 23245.01 -> 22666.61 (2.49%)

One of the biggest contributors to this slowdown (~2%) seem to be Exec_time_tracker. I get the following numbers if it is commented out (10.0 -> 10.1):

1 thread avg TPS: 805.91 -> 796.44 (1.18%)

1 thread max TPS: 810.60 -> 806.29 (0.53%)