we have a 4-way dualcore xeon server running mysql 5.0.27 with bufferpool-mutex-patch.
the load is entirely cpu/memory bound, no noticable disk activity.
If i set innodb_thread_concurrency to 16 or 32 and simulate a lot of load, i see that the system is overloaded but cpu usage is only at 20%.
If i set it to unlimited (0), i see cpu is going to 100%, but actually less queries are performed per second.
If i use SHOW MUTEX STATUS, the only mutex heavily used is the main bufferpool mutex, so I guess the concurrency problem is not entirely solved by the patch?