Talk about silly byte-shaving ... the "stock" value of STACK_MIN_SIZE does not work on s390x, and probably not on some other platforms either. Knock it up to twice the pre-5.0.33 value to have some margin for future changes in compiler, glibc, etc. Suspect this number if "execution_constants" regression test fails. Note: STACK_MIN_SIZE has to be enough less than DEFAULT_THREAD_STACK / 8 to provide some headroom, which means that its value can't be raised too much further without increasing the latter as well. diff -Naur mysql-5.0.45.orig/sql/mysql_priv.h mysql-5.0.45/sql/mysql_priv.h --- mysql-5.0.45.orig/sql/mysql_priv.h 2007-07-04 09:06:41.000000000 -0400 +++ mysql-5.0.45/sql/mysql_priv.h 2008-01-08 17:32:22.000000000 -0500 @@ -173,7 +173,7 @@ Feel free to raise this by the smallest amount you can to get the "execution_constants" test to pass. */ -#define STACK_MIN_SIZE 12000 // Abort if less stack during eval. +#define STACK_MIN_SIZE 16384 // Abort if less stack during eval. #define STACK_MIN_SIZE_FOR_OPEN 1024*80 #define STACK_BUFF_ALLOC 352 // For stack overrun checks