Can be enabled with --enable-lock-elision=yes at configure time.
+2013-07-02 Andi Kleen <ak@linux.intel.com>
+
+ * config.h.in (ENABLE_LOCK_ELISION): Add.
+ * configure.in (--enable-lock-elision): Add option.
+ * manual/install.texi: Document --enable lock elision.
+ * configure: Regenerate
+ * INSTALL: Regenerate.
+
2013-07-02 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/i386/i686/multiarch/strcasecmp.S (__strcasecmp): Enable
library. This option hardcodes the newly built C library path in
dynamic tests so that they can be invoked directly.
+`--enable-lock-elision=yes'
+ Enable lock elision for pthread mutexes and rwlocks by default.
+
`--build=BUILD-SYSTEM'
`--host=HOST-SYSTEM'
These options are for cross-compiling. If you specify both
/* Define if __stack_chk_guard canary should be randomized at program startup. */
#undef ENABLE_STACKGUARD_RANDOMIZE
+/* Define if lock elision should be enabled by default. */
+#undef ENABLE_LOCK_ELISION
+
/* Package description. */
#undef PKGVERSION
enable_oldest_abi
enable_hardcoded_path_in_tests
enable_stackguard_randomization
+enable_lock_elision
enable_add_ons
enable_hidden_plt
enable_bind_now
--enable-stackguard-randomization
initialize __stack_chk_guard canary with a random
number at program start
+ --enable-lock-elision=yes/no
+ Enable lock elision for pthread mutexes and rwlocks
+ by default
--enable-add-ons[=DIRS...]
configure and build add-ons in DIR1,DIR2,... search
for add-ons if no parameter given
fi
+# Check whether --enable-lock-elision was given.
+if test "${enable_lock_elision+set}" = set; then :
+ enableval=$enable_lock_elision; enable_lock_elision=$enableval
+else
+ enable_lock_elision=no
+fi
+
+if test "$enable_lock_elision" = yes ; then
+ $as_echo "#define ENABLE_LOCK_ELISION 1" >>confdefs.h
+
+fi
+
# Check whether --enable-add-ons was given.
if test "${enable_add_ons+set}" = set; then :
enableval=$enable_add_ons;
AC_DEFINE(ENABLE_STACKGUARD_RANDOMIZE)
fi
+AC_ARG_ENABLE([lock-elision],
+ AC_HELP_STRING([--enable-lock-elision[=yes/no]],
+ [Enable lock elision for pthread mutexes and rwlocks by default]),
+ [enable_lock_elision=$enableval],
+ [enable_lock_elision=no])
+if test "$enable_lock_elision" = yes ; then
+ AC_DEFINE(ENABLE_LOCK_ELISION)
+fi
+
dnl Generic infrastructure for drop-in additions to libc.
AC_ARG_ENABLE([add-ons],
AC_HELP_STRING([--enable-add-ons@<:@=DIRS...@:>@],
This option hardcodes the newly built C library path in dynamic tests
so that they can be invoked directly.
+@item --enable-lock-elision=yes
+Enable lock elision for pthread mutexes by default.
+
@item --build=@var{build-system}
@itemx --host=@var{host-system}
These options are for cross-compiling. If you specify both options and
+2013-07-02 Andi Kleen <ak@linux.intel.com>
+
+ * sysdeps/unix/sysv/linux/x86/elision-conf.c (elision_init):
+ Check ENABLE_LOCK_ELISION.
+
2013-07-02 Andi Kleen <ak@linux.intel.com>
* pthread_mutexattr_settype.c (__pthread_mutexattr_settype):
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
+#include "config.h"
#include <pthreadP.h>
#include <init-arch.h>
#include <elision-conf.h>
char **environ)
{
__elision_available = HAS_RTM;
+#ifdef ENABLE_LOCK_ELISION
__pthread_force_elision = __libc_enable_secure ? 0 : __elision_available;
__rwlock_rtm_enabled = __libc_enable_secure ? 0 : __elision_available;
+#endif
}
#ifdef SHARED