#At lp:maria 2703 knielsen@knielsen-hq.org 2009-06-10 Fix XtraDB to build with atomic operations, for good performance. The root of the problem is that ./configure mixed together two different things. One is the availability of GCC atomic operation intrinsics. The other is the selection of which primitives to use for my_atomic implementation. Then at some point a hack was made to not use GCC intrinsics in my_atomic to work around some test failures. But because the two things are mixed in ./configure, this as a side effect also makes GCC intrinsics unavailable for XtraDB. Fixed by splitting this in two in configure, so that we have HAVE_GCC_ATOMIC_BUILTINS for GCC intrinsics availability and MY_ATOMIC_MODE_GCC_BUILTINS for use in my_atomic. modified: configure.in include/atomic/nolock.h === modified file 'configure.in' --- a/configure.in 2009-04-23 13:06:16 +0000 +++ b/configure.in 2009-06-10 09:13:53 +0000 @@ -1726,6 +1726,30 @@ then fi fi +AC_CACHE_CHECK([whether the compiler provides atomic builtins], + [mysql_cv_gcc_atomic_builtins], [AC_TRY_RUN([ + int main() + { + int foo= -10; int bar= 10; + if (!__sync_fetch_and_add(&foo, bar) || foo) + return -1; + bar= __sync_lock_test_and_set(&foo, bar); + if (bar || foo != 10) + return -1; + bar= __sync_val_compare_and_swap(&bar, foo, 15); + if (bar) + return -1; + return 0; + } +], [mysql_cv_gcc_atomic_builtins=yes], + [mysql_cv_gcc_atomic_builtins=no], + [mysql_cv_gcc_atomic_builtins=no])]) + +if test "x$mysql_cv_gcc_atomic_builtins" = xyes; then + AC_DEFINE(HAVE_GCC_ATOMIC_BUILTINS, 1, + [Define to 1 if compiler provides atomic builtins.]) +fi + AC_ARG_WITH([atomic-ops], AC_HELP_STRING([--with-atomic-ops=rwlocks|smp|up], [Implement atomic operations using pthread rwlocks or atomic CPU @@ -1739,28 +1763,9 @@ case "$with_atomic_ops" in [Use pthread rwlocks for atomic ops]) ;; "smp") ;; "") - AC_CACHE_CHECK([whether the compiler provides atomic builtins], - [mysql_cv_gcc_atomic_builtins], [AC_TRY_RUN([ - int main() - { - int foo= -10; int bar= 10; - if (!__sync_fetch_and_add(&foo, bar) || foo) - return -1; - bar= __sync_lock_test_and_set(&foo, bar); - if (bar || foo != 10) - return -1; - bar= __sync_val_compare_and_swap(&bar, foo, 15); - if (bar) - return -1; - return 0; - } - ], [mysql_cv_gcc_atomic_builtins=yes_but_disabled], - [mysql_cv_gcc_atomic_builtins=no], - [mysql_cv_gcc_atomic_builtins=no])]) - - if test "x$mysql_cv_gcc_atomic_builtins" = xyes; then - AC_DEFINE(HAVE_GCC_ATOMIC_BUILTINS, 1, - [Define to 1 if compiler provides atomic builtins.]) + if test "x$mysql_cv_gcc_atomic_builtins" = xyes_but_disabled; then + AC_DEFINE([MY_ATOMIC_MODE_GCC_BUILTINS], [1], + [Use GCC atomic builtins for atomic ops]) fi ;; *) AC_MSG_ERROR(["$with_atomic_ops" is not a valid value for --with-atomic-ops]) ;; === modified file 'include/atomic/nolock.h' --- a/include/atomic/nolock.h 2008-02-05 15:47:11 +0000 +++ b/include/atomic/nolock.h 2009-06-10 09:13:53 +0000 @@ -14,7 +14,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #if defined(__i386__) || defined(_MSC_VER) || \ - defined(__x86_64__) || defined(HAVE_GCC_ATOMIC_BUILTINS) + defined(__x86_64__) || defined(MY_ATOMIC_MODE_GCC_BUILTINS) # ifdef MY_ATOMIC_MODE_DUMMY # define LOCK_prefix "" @@ -22,7 +22,7 @@ # define LOCK_prefix "lock" # endif -# ifdef HAVE_GCC_ATOMIC_BUILTINS +# ifdef MY_ATOMIC_MODE_GCC_BUILTINS # include "gcc_builtins.h" # elif __GNUC__ # include "x86-gcc.h"