Just a remark about adding Valgrind suppressions for problems in system libraries that we cannot fix. I see in mysql-test/valgrind.supp a number of suppressions like this: { dlclose memory loss from plugin variant 4 Memcheck:Leak fun:malloc obj:/lib*/ld-*.so obj:/lib*/ld-*.so obj:/lib*/ld-*.so obj:/lib*/libdl-*.so fun:dlclose fun:_ZL15free_plugin_memP12st_plugin_dl fun:_ZL13plugin_dl_delPK19st_mysql_lex_string } where these "obj:/lib*/ld-*.so" entries are caused by lack of debugging information, so Valgrind cannot provide proper stack traces. Please do not add any more suppressions like this. Instead, install debugging versions of the system libraries (this can be done without any loss of efficiency, as the debug libraries are only used when explicitly requested, eg. by `mtr --valgrind`). On Ubuntu/Debian: sudo apt-get install libc6-dbg On Suse: Enable the `debuginfo' repository (if not already enabled) Install the package `glibc-debuginfo' Then the needed suppression will look much nicer: { dlclose memory loss from plugin variant 2 Memcheck:Leak fun:malloc fun:_dl_close_worker fun:_dl_close fun:_dl_catch_error fun:_dlerror_run fun:dlclose fun:_ZL15free_plugin_memP12st_plugin_dl fun:_ZL13plugin_dl_delPK19st_mysql_lex_string } This way, we get fewer suppressions to maintain, and those we do need to maintain are much easier to read. - Kristian.