==10569== 176 bytes in 1 blocks are still reachable in loss record 2 of 6
==10569== at 0x4C26C3A: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==10569== by 0xC8B387: my_malloc (my_malloc.c:40)
==10569== by 0xC7EC2D: my_multi_malloc (mulalloc.c:50)
==10569== by 0xC98229: safe_mutex_lazy_init_deadlock_detection (thr_mutex.c:162)
==10569== by 0xC9875E: safe_mutex_lock (thr_mutex.c:322)
==10569== by 0x79E962: inline_mysql_mutex_lock (mysql_thread.h:618)
==10569== by 0x79F578: timer_thread(void*) (threadpool_unix.cc:470)
==10569== by 0xA91EDB: pfs_spawn_thread (pfs.cc:1015)
==10569== by 0x4E32A4E: start_thread (in /lib64/libpthread-2.11.2.so)
==10569== by 0x60EE82C: clone (in /lib64/libc-2.11.2.so)
==10569==
==10569== 2,048 bytes in 1 blocks are still reachable in loss record 5 of 6
==10569== at 0x4C26C3A: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==10569== by 0xC8B387: my_malloc (my_malloc.c:40)
==10569== by 0xC63CD5: init_dynamic_array2 (array.c:65)
==10569== by 0xC69203: _my_hash_init (hash.c:92)
==10569== by 0xC982E0: safe_mutex_lazy_init_deadlock_detection (thr_mutex.c:175)
==10569== by 0xC9875E: safe_mutex_lock (thr_mutex.c:322)
==10569== by 0x79E962: inline_mysql_mutex_lock (mysql_thread.h:618)
==10569== by 0x79F578: timer_thread(void*) (threadpool_unix.cc:470)
==10569== by 0xA91EDB: pfs_spawn_thread (pfs.cc:1015)
==10569== by 0x4E32A4E: start_thread (in /lib64/libpthread-2.11.2.so)
==10569== by 0x60EE82C: clone (in /lib64/libc-2.11.2.so)
==10569==
==10569== 2,048 bytes in 1 blocks are still reachable in loss record 6 of 6
==10569== at 0x4C26C3A: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==10569== by 0xC8B387: my_malloc (my_malloc.c:40)
==10569== by 0xC63CD5: init_dynamic_array2 (array.c:65)
==10569== by 0xC69203: _my_hash_init (hash.c:92)
==10569== by 0xC98329: safe_mutex_lazy_init_deadlock_detection (thr_mutex.c:180)
==10569== by 0xC9875E: safe_mutex_lock (thr_mutex.c:322)
==10569== by 0x79E962: inline_mysql_mutex_lock (mysql_thread.h:618)
==10569== by 0x79F578: timer_thread(void*) (threadpool_unix.cc:470)
==10569== by 0xA91EDB: pfs_spawn_thread (pfs.cc:1015)
==10569== by 0x4E32A4E: start_thread (in /lib64/libpthread-2.11.2.so)
==10569== by 0x60EE82C: clone (in /lib64/libc-2.11.2.so)
==10569==

I am getting it while running 1st test from the MTR main suite with valgrind-mysqld.
Not reproducible with thread_handling=one-thread-per-connection or no-threads.

bzr version-info
revision-id: <email address hidden>
date: 2011-12-28 03:51:12 +0100
build-date: 2011-12-28 18:07:54 +0200
revno: 3182
branch-nick: lp-5.5-threadpool