S/390: Port of lock elision to System/z

Added support for TX lock elision of pthread mutexes on s390 and
s390x.  This may improve lock scaling of existing programs on TX
capable systems.  The lock elision code is only built with
--enable-lock-elision=yes and then requires a GCC version supporting
the TX builtins.  With lock elision default mutexes are elided via
__builtin_tbegin, if the cpu supports transactions. By default lock
elision is not enabled and the elision code is not built.
This commit is contained in:
Dominik Vogt 2014-05-09 16:58:46 +02:00 committed by Andreas Krebbel
parent f63c86fed0
commit 5a414ff70c
21 changed files with 693 additions and 2 deletions

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@ -1,3 +1,38 @@
2014-05-09 Dominik Vogt <vogt@linux.vnet.ibm.com>
Stefan Liebler <stli@linux.vnet.ibm.com>
* config.make.in (enable-lock-elision): New Makefile variable.
* configure.ac: Likewise.
* configure: Regenerate.
* sysdeps/s390/configure.ac:
Add check for gcc transactions support.
* sysdeps/s390/configure: Regenerate.
* nptl/sysdeps/unix/sysv/linux/s390/Makefile: New file.
Build elision files if enabled.
* nptl/sysdeps/unix/sysv/linux/s390/elision-conf.c: New file.
Add lock elision support for s390.
* nptl/sysdeps/unix/sysv/linux/s390/elision-conf.h: Likewise.
* nptl/sysdeps/unix/sysv/linux/s390/elision-lock.c: Likewise.
* nptl/sysdeps/unix/sysv/linux/s390/elision-timed.c: Likewise.
* nptl/sysdeps/unix/sysv/linux/s390/elision-trylock.c: Likewise.
* nptl/sysdeps/unix/sysv/linux/s390/elision-unlock.c: Likewise.
* nptl/sysdeps/unix/sysv/linux/s390/force-elision.h: Likewise.
* nptl/sysdeps/unix/sysv/linux/s390/pthread_mutex_cond_lock.c:
Likewise.
* nptl/sysdeps/unix/sysv/linux/s390/pthread_mutex_lock.c:
Likewise.
* nptl/sysdeps/unix/sysv/linux/s390/pthread_mutex_timedlock.c:
Likewise.
* nptl/sysdeps/unix/sysv/linux/s390/pthread_mutex_trylock.c:
Likewise.
* nptl/sysdeps/unix/sysv/linux/s390/lowlevellock.h:
(__lll_timedlock_elision, __lll_lock_elision)
(__lll_unlock_elision, __lll_trylock_elision)
(lll_timedlock_elision, lll_lock_elision)
(lll_unlock_elision, lll_trylock_elision): Add.
* nptl/sysdeps/unix/sysv/linux/s390/bits/pthreadtypes.h
(pthread_mutex_t): Add lock elision support for s390.
2014-05-09 Will Newton <will.newton@linaro.org>
* sysdeps/arm/armv7/strcmp.S: New file.

8
NEWS
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@ -40,6 +40,14 @@ Version 2.20
test macros defined.
* Optimized strcmp implementation for ARMv7. Contributed by ARM Ltd.
* Added support for TX lock elision of pthread mutexes on s390 and s390x.
This may improve lock scaling of existing programs on TX capable systems.
The lock elision code is only built with --enable-lock-elision=yes and
then requires a GCC version supporting the TX builtins. With lock elision
default mutexes are elided via __builtin_tbegin, if the cpu supports
transactions. By default lock elision is not enabled and the elision code
is not built.
Version 2.19

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@ -93,6 +93,7 @@ build-nscd = @build_nscd@
use-nscd = @use_nscd@
build-hardcoded-path-in-tests= @hardcoded_path_in_tests@
build-pt-chown = @build_pt_chown@
enable-lock-elision = @enable_lock_elision@
# Build tools.
CC = @CC@

2
configure vendored
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@ -651,6 +651,7 @@ libc_cv_nss_crypt
all_warnings
force_install
bindnow
enable_lock_elision
hardcoded_path_in_tests
oldest_abi
use_default_link
@ -3476,6 +3477,7 @@ else
enable_lock_elision=no
fi
if test "$enable_lock_elision" = yes ; then
$as_echo "#define ENABLE_LOCK_ELISION 1" >>confdefs.h

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@ -184,6 +184,7 @@ AC_ARG_ENABLE([lock-elision],
[Enable lock elision for pthread mutexes by default]),
[enable_lock_elision=$enableval],
[enable_lock_elision=no])
AC_SUBST(enable_lock_elision)
if test "$enable_lock_elision" = yes ; then
AC_DEFINE(ENABLE_LOCK_ELISION)
fi

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@ -0,0 +1,10 @@
ifeq ($(enable-lock-elision),yes)
libpthread-sysdep_routines += elision-lock elision-unlock elision-timed \
elision-trylock
elision-CFLAGS = -mhtm
CFLAGS-elision-lock.c = $(elision-CFLAGS)
CFLAGS-elision-timed.c = $(elision-CFLAGS)
CFLAGS-elision-trylock.c = $(elision-CFLAGS)
CFLAGS-elision-unlock.c = $(elision-CFLAGS)
endif

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@ -89,14 +89,37 @@ typedef union
binary compatibility. */
int __kind;
#if __WORDSIZE == 64
# ifdef ENABLE_LOCK_ELISION
short __spins;
short __elision;
/* Mutex __spins initializer used by PTHREAD_MUTEX_INITIALIZER. */
# define __PTHREAD_SPINS 0, 0
# else
int __spins;
/* Mutex __spins initializer used by PTHREAD_MUTEX_INITIALIZER. */
# define __PTHREAD_SPINS 0
# endif
__pthread_list_t __list;
# define __PTHREAD_MUTEX_HAVE_PREV 1
#else
unsigned int __nusers;
__extension__ union
{
# ifdef ENABLE_LOCK_ELISION
struct
{
short __espins;
short __elision;
} _d;
# define __spins _d.__espins
# define __elision _d.__elision
/* Mutex __spins initializer used by PTHREAD_MUTEX_INITIALIZER. */
# define __PTHREAD_SPINS { 0, 0 }
# else
int __spins;
/* Mutex __spins initializer used by PTHREAD_MUTEX_INITIALIZER. */
# define __PTHREAD_SPINS 0
# endif
__pthread_slist_t __list;
};
#endif
@ -105,8 +128,6 @@ typedef union
long int __align;
} pthread_mutex_t;
/* Mutex __spins initializer used by PTHREAD_MUTEX_INITIALIZER. */
#define __PTHREAD_SPINS 0
typedef union
{

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@ -0,0 +1,82 @@
/* Lock elision tunable parameters.
Copyright (C) 2014 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 <elision-conf.h>
#include <unistd.h>
#include <dl-procinfo.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 to not attempt to use elision if a lock used up all retries
without success. Expressed in number of lock acquisition attempts. */
.skip_lock_out_of_tbegin_retries = 3,
/* How often we try 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. */
.try_tbegin = 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 = 0;
/* Initialize elison. */
static void
elision_init (int argc __attribute__ ((unused)),
char **argv __attribute__ ((unused)),
char **environ)
{
/* Set when the CPU and the kernel supports transactional execution.
When false elision is never attempted. */
int elision_available = (GLRO (dl_hwcap) & HWCAP_S390_TE) ? 1 : 0;
__pthread_force_elision = __libc_enable_secure ? 0 : elision_available;
}
#ifdef SHARED
# define INIT_SECTION ".init_array"
# define MAYBE_CONST
#else
# define INIT_SECTION ".preinit_array"
# define MAYBE_CONST const
#endif
void (*MAYBE_CONST __pthread_init_array []) (int, char **, char **)
__attribute__ ((section (INIT_SECTION), aligned (sizeof (void *)))) =
{
&elision_init
};

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@ -0,0 +1,44 @@
/* Lock elision tunable parameters.
Copyright (C) 2014 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/>. */
#ifdef ENABLE_LOCK_ELISION
#ifndef _ELISION_CONF_H
#define _ELISION_CONF_H 1
#include <pthread.h>
#include <time.h>
/* Should make sure there is no false sharing on this. */
struct elision_config
{
int skip_lock_busy;
int skip_lock_internal_abort;
int skip_lock_out_of_tbegin_retries;
int try_tbegin;
int skip_trylock_internal_abort;
};
extern struct elision_config __elision_aconf attribute_hidden;
extern int __pthread_force_elision attribute_hidden;
/* Tell the test suite to test elision for this architecture. */
#define HAVE_ELISION 1
#endif
#endif

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@ -0,0 +1,119 @@
/* Elided pthread mutex lock.
Copyright (C) 2014 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 <pthread.h>
#include <pthreadP.h>
#include <lowlevellock.h>
#include <htmintrin.h>
#include <elision-conf.h>
#include <stdint.h>
#if !defined(LLL_LOCK) && !defined(EXTRAARG)
/* Make sure the configuration code is always linked in for static
libraries. */
#include "elision-conf.c"
#endif
#ifndef EXTRAARG
#define EXTRAARG
#endif
#ifndef LLL_LOCK
#define LLL_LOCK(a,b) lll_lock(a,b), 0
#endif
#define aconf __elision_aconf
/* Adaptive lock using transactions.
By default the lock region is run as a transaction, and when it
aborts or the lock is busy the lock adapts itself. */
int
__lll_lock_elision (int *futex, short *adapt_count, EXTRAARG int private)
{
if (*adapt_count > 0)
{
/* Lost updates are possible, but harmless. Due to races this might lead
to *adapt_count becoming less than zero. */
(*adapt_count)--;
goto use_lock;
}
__asm__ volatile (".machinemode \"zarch_nohighgprs\"\n\t"
".machine \"all\""
: : : "memory");
int try_tbegin;
for (try_tbegin = aconf.try_tbegin;
try_tbegin > 0;
try_tbegin--)
{
unsigned status;
if (__builtin_expect
((status = __builtin_tbegin((void *)0)) == _HTM_TBEGIN_STARTED, 1))
{
if (*futex == 0)
return 0;
/* Lock was busy. Fall back to normal locking. */
if (__builtin_expect (__builtin_tx_nesting_depth (), 1))
{
/* In a non-nested transaction there is no need to abort,
which is expensive. */
__builtin_tend ();
if (aconf.skip_lock_busy > 0)
*adapt_count = aconf.skip_lock_busy;
goto use_lock;
}
else /* nesting depth is > 1 */
{
/* A nested transaction will abort eventually because it
cannot make any progress before *futex changes back to 0.
So we may as well abort immediately.
This persistently aborts the outer transaction to force
the outer mutex use the default lock instead of retrying
with transactions until the try_tbegin of the outer mutex
is zero.
The adapt_count of this inner mutex is not changed,
because using the default lock with the inner mutex
would abort the outer transaction.
*/
__builtin_tabort (_HTM_FIRST_USER_ABORT_CODE | 1);
}
}
else
{
if (status != _HTM_TBEGIN_TRANSIENT)
{
/* A persistent abort (cc 1 or 3) indicates that a retry is
probably futile. Use the normal locking now and for the
next couple of calls.
Be careful to avoid writing to the lock. */
if (aconf.skip_lock_internal_abort > 0)
*adapt_count = aconf.skip_lock_internal_abort;
goto use_lock;
}
}
}
/* Same logic as above, but for for a number of temporary failures in a
row. */
if (aconf.skip_lock_out_of_tbegin_retries > 0 && aconf.try_tbegin > 0)
*adapt_count = aconf.skip_lock_out_of_tbegin_retries;
use_lock:
return LLL_LOCK ((*futex), private);
}

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@ -0,0 +1,26 @@
/* Lock elision timed lock.
Copyright (C) 2014 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 <time.h>
#include <elision-conf.h>
#include <lowlevellock.h>
#define __lll_lock_elision __lll_timedlock_elision
#define EXTRAARG const struct timespec *t,
#undef LLL_LOCK
#define LLL_LOCK(a, b) lll_timedlock(a, t, b)
#include "elision-lock.c"

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@ -0,0 +1,94 @@
/* Elided pthread mutex trylock.
Copyright (C) 2014 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 <pthread.h>
#include <pthreadP.h>
#include <lowlevellock.h>
#include <htmintrin.h>
#include <elision-conf.h>
#define aconf __elision_aconf
/* Try to elide a futex trylock. FUTEX is the futex variable. ADAPT_COUNT is
the adaptation counter in the mutex. */
int
__lll_trylock_elision (int *futex, short *adapt_count)
{
__asm__ volatile (".machinemode \"zarch_nohighgprs\"\n\t"
".machine \"all\""
: : : "memory");
/* Implement POSIX semantics by forbiding nesting elided trylocks.
Sorry. After the abort the code is re-executed
non transactional and if the lock was already locked
return an error. */
if (__builtin_tx_nesting_depth () > 0)
{
/* Note that this abort may terminate an outermost transaction that
was created outside glibc.
This persistently aborts the current transactions to force
them to use the default lock instead of retrying transactions
until their try_tbegin is zero.
*/
__builtin_tabort (_HTM_FIRST_USER_ABORT_CODE | 1);
}
/* Only try a transaction if it's worth it. */
if (*adapt_count <= 0)
{
unsigned status;
if (__builtin_expect
((status = __builtin_tbegin ((void *)0)) == _HTM_TBEGIN_STARTED, 1))
{
if (*futex == 0)
return 0;
/* Lock was busy. Fall back to normal locking. */
/* Since we are in a non-nested transaction there is no need to abort,
which is expensive. */
__builtin_tend ();
/* Note: Changing the adapt_count here might abort a transaction on a
different cpu, but that could happen anyway when the futex is
acquired, so there's no need to check the nesting depth here. */
if (aconf.skip_lock_busy > 0)
*adapt_count = aconf.skip_lock_busy;
}
else
{
if (status != _HTM_TBEGIN_TRANSIENT)
{
/* A persistent abort (cc 1 or 3) indicates that a retry is
probably futile. Use the normal locking now and for the
next couple of calls.
Be careful to avoid writing to the lock. */
if (aconf.skip_trylock_internal_abort > 0)
*adapt_count = aconf.skip_trylock_internal_abort;
}
}
/* Could do some retries here. */
}
else
{
/* Lost updates are possible, but harmless. Due to races this might lead
to *adapt_count becoming less than zero. */
(*adapt_count)--;
}
return lll_trylock (*futex);
}

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@ -0,0 +1,38 @@
/* Commit an elided pthread lock.
Copyright (C) 2014 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 <pthreadP.h>
#include <lowlevellock.h>
int
__lll_unlock_elision(int *futex, int private)
{
/* If the lock is free, we elided the lock earlier. This does not
necessarily mean that we are in a transaction, because the user code may
have closed the transaction, but that is impossible to detect reliably. */
if (*futex == 0)
{
__asm__ volatile (".machinemode \"zarch_nohighgprs\"\n\t"
".machine \"all\""
: : : "memory");
__builtin_tend();
}
else
lll_unlock ((*futex), private);
return 0;
}

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@ -0,0 +1,33 @@
/* Automatic enabling of elision for mutexes
Copyright (C) 2014 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/>. */
#ifdef ENABLE_LOCK_ELISION
/* Check for elision on this lock without upgrading. */
#define DO_ELISION(m) \
(__pthread_force_elision \
&& (m->__data.__kind & PTHREAD_MUTEX_NO_ELISION_NP) == 0) \
/* Automatically enable elision for existing user lock kinds. */
#define FORCE_ELISION(m, s) \
if (__pthread_force_elision \
&& (m->__data.__kind & PTHREAD_MUTEX_ELISION_FLAGS_NP) == 0) \
{ \
mutex->__data.__kind |= PTHREAD_MUTEX_ELISION_NP; \
s; \
}
#endif

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@ -285,6 +285,15 @@ __lll_timedlock (int *futex, const struct timespec *abstime, int private)
#define lll_timedlock(futex, abstime, private) \
__lll_timedlock (&(futex), abstime, private)
#ifdef ENABLE_LOCK_ELISION
extern int __lll_timedlock_elision
(int *futex, short *adapt_count, const struct timespec *timeout, int private)
attribute_hidden;
# define lll_timedlock_elision(futex, adapt_count, timeout, private) \
__lll_timedlock_elision(&(futex), &(adapt_count), timeout, private)
#endif
static inline int
__attribute__ ((always_inline))
__lll_robust_timedlock (int *futex, const struct timespec *abstime,
@ -360,4 +369,22 @@ extern int __lll_timedwait_tid (int *, const struct timespec *)
__res; \
})
#ifdef ENABLE_LOCK_ELISION
extern int __lll_lock_elision (int *futex, short *adapt_count, int private)
attribute_hidden;
extern int __lll_unlock_elision(int *futex, int private)
attribute_hidden;
extern int __lll_trylock_elision(int *futex, short *adapt_count)
attribute_hidden;
# define lll_lock_elision(futex, adapt_count, private) \
__lll_lock_elision (&(futex), &(adapt_count), private)
# define lll_unlock_elision(futex, private) \
__lll_unlock_elision (&(futex), private)
# define lll_trylock_elision(futex, adapt_count) \
__lll_trylock_elision(&(futex), &(adapt_count))
#endif
#endif /* lowlevellock.h */

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@ -0,0 +1,22 @@
/* Copyright (C) 2014 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/>. */
/* The cond lock is not actually elided yet, but we still need to handle
already elided locks. */
#include <elision-conf.h>
#include <nptl/sysdeps/unix/sysv/linux/pthread_mutex_cond_lock.c>

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@ -0,0 +1,22 @@
/* Elided version of pthread_mutex_lock.
Copyright (C) 2014 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 <elision-conf.h>
#include <force-elision.h>
#include <nptl/pthread_mutex_lock.c>

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@ -0,0 +1,22 @@
/* Elided version of pthread_mutex_timedlock.
Copyright (C) 2014 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 <elision-conf.h>
#include <force-elision.h>
#include <nptl/pthread_mutex_timedlock.c>

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@ -0,0 +1,22 @@
/* Elided version of pthread_mutex_trylock.
Copyright (C) 2014 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 <elision-conf.h>
#include <force-elision.h>
#include <nptl/pthread_mutex_trylock.c>

View File

@ -68,5 +68,41 @@ if test $ac_verc_fail = yes; then
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for __builtin_tbegin" >&5
$as_echo_n "checking for __builtin_tbegin... " >&6; }
if ${libc_cv_gcc_builtin_tbegin+:} false; then :
$as_echo_n "(cached) " >&6
else
cat > conftest.c <<\EOF
#include <htmintrin.h>
void testtransaction ()
{
if (__builtin_tbegin (0) == _HTM_TBEGIN_STARTED)
{
__builtin_tend ();
}
}
EOF
if { ac_try='${CC-cc} -mhtm -O2 -S conftest.c -o - | grep -w tbegin > /dev/null'
{ { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
(eval $ac_try) 2>&5
ac_status=$?
$as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
test $ac_status = 0; }; } ;
then
libc_cv_gcc_builtin_tbegin=yes
else
libc_cv_gcc_builtin_tbegin=no
fi
rm -f conftest*
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_gcc_builtin_tbegin" >&5
$as_echo "$libc_cv_gcc_builtin_tbegin" >&6; }
if test "$enable_lock_elision" = yes && test "$libc_cv_gcc_builtin_tbegin" = no ; then
critic_missing="$critic_missing The used GCC has no support for __builtin_tbegin, which is needed for lock-elision on target S390."
fi
test -n "$critic_missing" && as_fn_error $? "
*** $critic_missing" "$LINENO" 5

View File

@ -10,5 +10,31 @@ AC_CHECK_PROG_VER(AS, $AS, --version,
[GNU assembler.* \([0-9]*\.[0-9.]*\)],
[2.2[4-9]*|2.[3-9][0-9]*|[3-9].*|[1-9][0-9]*], critic_missing="$critic_missing The program AS is required in version >= 2.24 for target S390.")
AC_CACHE_CHECK(for __builtin_tbegin, libc_cv_gcc_builtin_tbegin, [dnl
cat > conftest.c <<\EOF
#include <htmintrin.h>
void testtransaction ()
{
if (__builtin_tbegin (0) == _HTM_TBEGIN_STARTED)
{
__builtin_tend ();
}
}
EOF
dnl
dnl test, if the tbegin instruction is used by __builtin_tbegin
if AC_TRY_COMMAND([${CC-cc} -mhtm -O2 -S conftest.c -o - | grep -w tbegin > /dev/null]) ;
then
libc_cv_gcc_builtin_tbegin=yes
else
libc_cv_gcc_builtin_tbegin=no
fi
rm -f conftest* ])
if test "$enable_lock_elision" = yes && test "$libc_cv_gcc_builtin_tbegin" = no ; then
critic_missing="$critic_missing The used GCC has no support for __builtin_tbegin, which is needed for lock-elision on target S390."
fi
test -n "$critic_missing" && AC_MSG_ERROR([
*** $critic_missing])