Have your tests been performed with XtraDB in MariaDB or in Percona Server? (I wonder if there could be a difference in defaults). Could you please check innodb_buffer_pool_instances, innodb_lru_scan_depth values? (or just paste SELECT * FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES)
Have your tests been performed with XtraDB in MariaDB or in Percona Server? (I wonder if there could be a difference in defaults). Could you please check innodb_ buffer_ pool_instances, innodb_ lru_scan_ depth values? (or just paste SELECT * FROM INFORMATION_ SCHEMA. GLOBAL_ VARIABLES)