1 files changed, 78 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/unix/sysv/linux/x86/elision-conf.c b/REORG.TODO/sysdeps/unix/sysv/linux/x86/elision-conf.c
new file mode 100644
index 0000000000..673b0005a7
--- /dev/null
+++ b/REORG.TODO/sysdeps/unix/sysv/linux/x86/elision-conf.c
@@ -0,0 +1,78 @@
+/* elision-conf.c: Lock elision tunable parameters.
+   Copyright (C) 2013-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   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>
+#include <unistd.h>
+
+/* Reasonable initial tuning values, may be revised in the future.
+   This is a conservative initial value.  */
+
+struct elision_config __elision_aconf =
+  {
+    /* How often to not attempt to use elision if a transaction aborted
+       because the lock is already acquired.  Expressed in number of lock
+       acquisition attempts.  */
+    .skip_lock_busy = 3,
+    /* How often to not attempt to use elision if a transaction aborted due
+       to reasons other than other threads' memory accesses.  Expressed in
+       number of lock acquisition attempts.  */
+    .skip_lock_internal_abort = 3,
+    /* How often we retry using elision if there is chance for the transaction
+       to finish execution (e.g., it wasn't aborted due to the lock being
+       already acquired.  */
+    .retry_try_xbegin = 3,
+    /* Same as SKIP_LOCK_INTERNAL_ABORT but for trylock.  */
+    .skip_trylock_internal_abort = 3,
+  };
+
+/* Force elision for all new locks.  This is used to decide whether existing
+   DEFAULT locks should be automatically upgraded to elision in
+   pthread_mutex_lock().  Disabled for suid programs.  Only used when elision
+   is available.  */
+
+int __pthread_force_elision attribute_hidden;
+
+/* Initialize elison.  */
+
+static void
+elision_init (int argc __attribute__ ((unused)),
+	      char **argv  __attribute__ ((unused)),
+	      char **environ)
+{
+  int elision_available = HAS_CPU_FEATURE (RTM);
+#ifdef ENABLE_LOCK_ELISION
+  __pthread_force_elision = __libc_enable_secure ? 0 : elision_available;
+#endif
+  if (!elision_available)
+    __elision_aconf.retry_try_xbegin = 0; /* Disable elision on rwlocks */
+}
+
+#ifdef SHARED
+# define INIT_SECTION ".init_array"
+#else
+# define INIT_SECTION ".preinit_array"
+#endif
+
+void (*const __pthread_init_array []) (int, char **, char **)
+  __attribute__ ((section (INIT_SECTION), aligned (sizeof (void *)))) =
+{
+  &elision_init
+};