Hi Axel, I benchmarked various mutexes available to MariaDB. Results are here: http://svoj-db.blogspot.ru/2014/02/mariadb-mutexes-scalability.html Among other things I noticed that normal mutexes scale better than adaptive. And it looks like it gives over 5 000 TPS in my benchmarks: Original -------- 64 threads, time spent: 60s, queries executed: 11500723, qps: 191678, 1 thread qps: 2994, tps: 13691 64 threads, time spent: 60s, queries executed: 10983665, qps: 183061, 1 thread qps: 2860, tps: 13075 64 threads, time spent: 60s, queries executed: 11080325, qps: 184672, 1 thread qps: 2885, tps: 13190 slow LOCK_open -------------- 64 threads, time spent: 60s, queries executed: 12948365, qps: 215806, 1 thread qps: 3371, tps: 15414 64 threads, time spent: 60s, queries executed: 13191584, qps: 219859, 1 thread qps: 3435, tps: 15704 64 threads, time spent: 60s, queries executed: 13050647, qps: 217510, 1 thread qps: 3398, tps: 15536 slow LOCK_open + THR_LOCK::mutex -------------------------------- 64 threads, time spent: 60s, queries executed: 15863174, qps: 264386, 1 thread qps: 4131, tps: 18884 64 threads, time spent: 60s, queries executed: 15761944, qps: 262699, 1 thread qps: 4104, tps: 18764 64 threads, time spent: 60s, queries executed: 15773239, qps: 262887, 1 thread qps: 4107, tps: 18777 Could you do official benchmarks (patch attached)? It would be nice to also benchmark MySQL-5.6 with thr_lock part of the patch. Thanks, Sergey