File _service:tar_scm:0006-add-elsion-function-which... of Package glibc

File _service:tar_scm:0006-add-elsion-function-which-moved-to-libc-in-glibc-2.34.patch of Package glibc (Revision a9324b4a012a51f62305bf2197548113)

Currently displaying revision a9324b4a012a51f62305bf2197548113 , Show latest

From 1cdbe579482c07e9f4bb3baa4864da2d3e7eb837 Mon Sep 17 00:00:00 2001
From: Andi Kleen <ak@linux.intel.com>
Date: Sat, 10 Nov 2012 00:51:26 -0800i
Subject: [PATCH 6/9] build extra lipthreadcond so

add elsion functions which moved to libc in glibc-2.34.
Some attributes are changed and cannot be directly referenced.

---
 nptl_2_17/lll_timedlock_wait_2_17.c | 59 +++++++++++++++++++++++++++++
 nptl_2_17/elision-conf_2_17.c    | 138 +++++++++++++++++++++++++++++++
 nptl_2_17/elision-lock_2_17.c    | 107 ++++++++++++++++++++++++
 nptl_2_17/elision-timed_2_17.c   |  27 ++++++
 nptl_2_17/elision-trylock_2_17.c |  75 +++++++++++++++++
 nptl_2_17/elision-unlock_2_17.c  |  34 ++++++++
 nptl_2_17/hle_2_17.h             |  75 +++++++++++++++++
 6 files changed, 515
  insertions(+)
 create mode 100644 nptl_2_17/lll_timedlock_wait_2_17.c
 create mode 100644 nptl_2_17/elision-conf_2_17.c
 create mode 100644 nptl_2_17/elision-lock_2_17.c
 create mode 100644 nptl_2_17/elision-timed_2_17.c
 create mode 100644 nptl_2_17/elision-trylock_2_17.c
 create mode 100644 nptl_2_17/elision-unlock_2_17.c
 create mode 100644 nptl_2_17/hle_2_17.h

diff --git a/nptl_2_17/lll_timedlock_wait_2_17.c b/nptl_2_17/lll_timedlock_wait_2_17.c
new file mode 100644
index 00000000..91bf9637
--- /dev/null
+++ b/nptl_2_17/lll_timedlock_wait_2_17.c
@@ -0,0 +1,59 @@
+/* Timed low level locking for pthread library.  Generic futex-using version.
+   Copyright (C) 2003-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
+
+   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 <atomic.h>
+#include <errno.h>
+#include <lowlevellock.h>
+#include <sys/time.h>
+
+
+int
+__lll_timedlock_wait (int *futex, const struct timespec *abstime, int private)
+{
+  /* Reject invalid timeouts.  */
+  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+    return EINVAL;
+
+  /* Try locking.  */
+  while (atomic_exchange_acq (futex, 2) != 0)
+    {
+      struct timeval tv;
+
+      /* Get the current time.  */
+      (void) __gettimeofday (&tv, NULL);
+
+      /* Compute relative timeout.  */
+      struct timespec rt;
+      rt.tv_sec = abstime->tv_sec - tv.tv_sec;
+      rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
+      if (rt.tv_nsec < 0)
+        {
+          rt.tv_nsec += 1000000000;
+          --rt.tv_sec;
+        }
+
+      if (rt.tv_sec < 0)
+        return ETIMEDOUT;
+
+      /* If *futex == 2, wait until woken or timeout.  */
+      lll_futex_timed_wait (futex, 2, &rt, private);
+    }
+
+  return 0;
+}
diff --git a/nptl_2_17/elision-conf_2_17.c b/nptl_2_17/elision-conf_2_17.c
new file mode 100644
index 00000000..22af2944
--- /dev/null
+++ b/nptl_2_17/elision-conf_2_17.c
@@ -0,0 +1,138 @@
+/* elision-conf.c: Lock elision tunable parameters.
+   Copyright (C) 2013-2018 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>
+
+#if HAVE_TUNABLES
+# define TUNABLE_NAMESPACE elision
+#endif
+#include <elf/dl-tunables.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 = 0;
+
+#if HAVE_TUNABLES
+static inline void
+__always_inline
+do_set_elision_enable (int32_t elision_enable)
+{
+  /* Enable elision if it's avaliable in hardware. It's not necessary to check
+     if __libc_enable_secure isn't enabled since elision_enable will be set
+     according to the default, which is disabled.  */
+  if (elision_enable == 1)
+    __pthread_force_elision = HAS_CPU_FEATURE (RTM) ? 1 : 0;
+}
+
+/* The pthread->elision_enable tunable is 0 or 1 indicating that elision
+   should be disabled or enabled respectively.  The feature will only be used
+   if it's supported by the hardware.  */
+
+void
+TUNABLE_CALLBACK (set_elision_enable) (tunable_val_t *valp)
+{
+  int32_t elision_enable = (int32_t) valp->numval;
+  do_set_elision_enable (elision_enable);
+}
+
+#define TUNABLE_CALLBACK_FNDECL(__name, __type)			\
+static inline void						\
+__always_inline							\
+do_set_elision_ ## __name (__type value)			\
+{								\
+  __elision_aconf.__name = value;				\
+}								\
+void								\
+TUNABLE_CALLBACK (set_elision_ ## __name) (tunable_val_t *valp) \
+{								\
+  __type value = (__type) (valp)->numval;			\
+  do_set_elision_ ## __name (value);				\
+}
+
+TUNABLE_CALLBACK_FNDECL (skip_lock_busy, int32_t);
+TUNABLE_CALLBACK_FNDECL (skip_lock_internal_abort, int32_t);
+TUNABLE_CALLBACK_FNDECL (retry_try_xbegin, int32_t);
+TUNABLE_CALLBACK_FNDECL (skip_trylock_internal_abort, int32_t);
+#endif
+
+/* Initialize elision.  */
+
+static void
+elision_init (int argc __attribute__ ((unused)),
+	      char **argv  __attribute__ ((unused)),
+	      char **environ)
+{
+#if HAVE_TUNABLES
+  /* Elision depends on tunables and must be explicitly turned on by setting
+     the appropriate tunable on a supported platform.  */
+
+  TUNABLE_GET (enable, int32_t,
+	       TUNABLE_CALLBACK (set_elision_enable));
+  TUNABLE_GET (skip_lock_busy, int32_t,
+	       TUNABLE_CALLBACK (set_elision_skip_lock_busy));
+  TUNABLE_GET (skip_lock_internal_abort, int32_t,
+	       TUNABLE_CALLBACK (set_elision_skip_lock_internal_abort));
+  TUNABLE_GET (tries, int32_t,
+	       TUNABLE_CALLBACK (set_elision_retry_try_xbegin));
+  TUNABLE_GET (skip_trylock_internal_abort, int32_t,
+	       TUNABLE_CALLBACK (set_elision_skip_trylock_internal_abort));
+#endif
+
+  if (!__pthread_force_elision)
+    __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
+};
diff --git a/nptl_2_17/elision-lock_2_17.c b/nptl_2_17/elision-lock_2_17.c
new file mode 100644
index 00000000..e6dbbc21
--- /dev/null
+++ b/nptl_2_17/elision-lock_2_17.c
@@ -0,0 +1,107 @@
+/* elision-lock.c: Elided pthread mutex lock.
+   Copyright (C) 2011-2018 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_2_17.h>
+#include "pthreadP_2_17.h"
+#include "lowlevellock.h"
+#include "hle_2_17.h"
+#include <elision-conf.h>
+
+#if !defined(LLL_LOCK) && !defined(EXTRAARG)
+/* Make sure the configuration code is always linked in for static
+   libraries.  */
+#include "elision-conf_2_17.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)
+{
+  /* adapt_count can be accessed concurrently; these accesses can be both
+     inside of transactions (if critical sections are nested and the outer
+     critical section uses lock elision) and outside of transactions.  Thus,
+     we need to use atomic accesses to avoid data races.  However, the
+     value of adapt_count is just a hint, so relaxed MO accesses are
+     sufficient.  */
+  if (atomic_load_relaxed (adapt_count) <= 0)
+    {
+      unsigned status;
+      int try_xbegin;
+
+      for (try_xbegin = aconf.retry_try_xbegin;
+	   try_xbegin > 0;
+	   try_xbegin--)
+	{
+	  if ((status = _xbegin()) == _XBEGIN_STARTED)
+	    {
+	      if (*futex == 0)
+		return 0;
+
+	      /* Lock was busy.  Fall back to normal locking.
+		 Could also _xend here but xabort with 0xff code
+		 is more visible in the profiler.  */
+	      _xabort (_ABORT_LOCK_BUSY);
+	    }
+
+	  if (!(status & _XABORT_RETRY))
+	    {
+	      if ((status & _XABORT_EXPLICIT)
+			&& _XABORT_CODE (status) == _ABORT_LOCK_BUSY)
+	        {
+		  /* Right now we skip here.  Better would be to wait a bit
+		     and retry.  This likely needs some spinning.  See
+		     above for why relaxed MO is sufficient.  */
+		  if (atomic_load_relaxed (adapt_count)
+		      != aconf.skip_lock_busy)
+		    atomic_store_relaxed (adapt_count, aconf.skip_lock_busy);
+		}
+	      /* Internal abort.  There is no chance for retry.
+		 Use the normal locking and next time use lock.
+		 Be careful to avoid writing to the lock.  See above for why
+		 relaxed MO is sufficient.  */
+	      else if (atomic_load_relaxed (adapt_count)
+		  != aconf.skip_lock_internal_abort)
+		atomic_store_relaxed (adapt_count,
+		    aconf.skip_lock_internal_abort);
+	      break;
+	    }
+	}
+    }
+  else
+    {
+      /* Use a normal lock until the threshold counter runs out.
+	 Lost updates possible.  */
+      atomic_store_relaxed (adapt_count,
+	  atomic_load_relaxed (adapt_count) - 1);
+    }
+
+  /* Use a normal lock here.  */
+  return LLL_LOCK ((*futex), private);
+}
diff --git a/nptl_2_17/elision-timed_2_17.c b/nptl_2_17/elision-timed_2_17.c
new file mode 100644
index 00000000..5050f2d1
--- /dev/null
+++ b/nptl_2_17/elision-timed_2_17.c
@@ -0,0 +1,27 @@
+/* elision-timed.c: Lock elision timed lock.
+   Copyright (C) 2013-2018 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"
+#include <old_macros_2_17.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_2_17.c"
diff --git a/nptl_2_17/elision-trylock_2_17.c b/nptl_2_17/elision-trylock_2_17.c
new file mode 100644
index 00000000..70d8f8b9
--- /dev/null
+++ b/nptl_2_17/elision-trylock_2_17.c
@@ -0,0 +1,75 @@
+/* elision-trylock.c: Lock eliding trylock for pthreads.
+   Copyright (C) 2013-2018 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_2_17.h>
+
+#include <lowlevellock.h>
+#include "hle_2_17.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)
+{
+  /* Implement POSIX semantics by forbiding nesting
+     trylock.  Sorry.  After the abort the code is re-executed
+     non transactional and if the lock was already locked
+     return an error.  */
+  _xabort (_ABORT_NESTED_TRYLOCK);
+
+  /* Only try a transaction if it's worth it.  See __lll_lock_elision for
+     why we need atomic accesses.  Relaxed MO is sufficient because this is
+     just a hint.  */
+  if (atomic_load_relaxed (adapt_count) <= 0)
+    {
+      unsigned status;
+
+      if ((status = _xbegin()) == _XBEGIN_STARTED)
+	{
+	  if (*futex == 0)
+	    return 0;
+
+	  /* Lock was busy.  Fall back to normal locking.
+	     Could also _xend here but xabort with 0xff code
+	     is more visible in the profiler.  */
+	  _xabort (_ABORT_LOCK_BUSY);
+	}
+
+      if (!(status & _XABORT_RETRY))
+        {
+          /* Internal abort.  No chance for retry.  For future
+             locks don't try speculation for some time.  See above for MO.  */
+          if (atomic_load_relaxed (adapt_count)
+              != aconf.skip_lock_internal_abort)
+            atomic_store_relaxed (adapt_count, aconf.skip_lock_internal_abort);
+        }
+      /* Could do some retries here.  */
+    }
+  else
+    {
+      /* Lost updates are possible but harmless (see above).  */
+      atomic_store_relaxed (adapt_count,
+	  atomic_load_relaxed (adapt_count) - 1);
+    }
+
+  return lll_trylock (*futex);
+}
diff --git a/nptl_2_17/elision-unlock_2_17.c b/nptl_2_17/elision-unlock_2_17.c
new file mode 100644
index 00000000..b5d38c5f
--- /dev/null
+++ b/nptl_2_17/elision-unlock_2_17.c
@@ -0,0 +1,34 @@
+/* elision-unlock.c: Commit an elided pthread lock.
+   Copyright (C) 2013-2018 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_2_17.h"
+#include "lowlevellock.h"
+#include "hle_2_17.h"
+#include <old_macros_2_17.h>
+
+int
+__lll_unlock_elision(int *lock, int private)
+{
+  /* When the lock was free we're in a transaction.
+     When you crash here you unlocked a free lock.  */
+  if (*lock == 0)
+    _xend();
+  else
+    lll_unlock ((*lock), private);
+  return 0;
+}
diff --git a/nptl_2_17/hle_2_17.h b/nptl_2_17/hle_2_17.h
new file mode 100644
index 00000000..4a7b9e3b
--- /dev/null
+++ b/nptl_2_17/hle_2_17.h
@@ -0,0 +1,75 @@
+/* Shared RTM header.  Emulate TSX intrinsics for compilers and assemblers
+   that do not support the intrinsics and instructions yet.  */
+#ifndef _HLE_H
+#define _HLE_H 1
+
+#ifdef __ASSEMBLER__
+
+.macro XBEGIN target
+	.byte 0xc7,0xf8
+	.long \target-1f
+1:
+.endm
+
+.macro XEND
+	.byte 0x0f,0x01,0xd5
+.endm
+
+.macro XABORT code
+	.byte 0xc6,0xf8,\code
+.endm
+
+.macro XTEST
+	 .byte 0x0f,0x01,0xd6
+.endm
+
+#endif
+
+/* Official RTM intrinsics interface matching gcc/icc, but works
+   on older gcc compatible compilers and binutils.
+   We should somehow detect if the compiler supports it, because
+   it may be able to generate slightly better code.  */
+
+#define _XBEGIN_STARTED		(~0u)
+#define _XABORT_EXPLICIT	(1 << 0)
+#define _XABORT_RETRY		(1 << 1)
+#define _XABORT_CONFLICT	(1 << 2)
+#define _XABORT_CAPACITY	(1 << 3)
+#define _XABORT_DEBUG		(1 << 4)
+#define _XABORT_NESTED		(1 << 5)
+#define _XABORT_CODE(x)		(((x) >> 24) & 0xff)
+
+#define _ABORT_LOCK_BUSY 	0xff
+#define _ABORT_LOCK_IS_LOCKED	0xfe
+#define _ABORT_NESTED_TRYLOCK	0xfd
+
+#ifndef __ASSEMBLER__
+
+#define __force_inline __attribute__((__always_inline__)) inline
+
+static __force_inline int _xbegin(void)
+{
+  int ret = _XBEGIN_STARTED;
+  asm volatile (".byte 0xc7,0xf8 ; .long 0" : "+a" (ret) :: "memory");
+  return ret;
+}
+
+static __force_inline void _xend(void)
+{
+  asm volatile (".byte 0x0f,0x01,0xd5" ::: "memory");
+}
+
+static __force_inline void _xabort(const unsigned int status)
+{
+  asm volatile (".byte 0xc6,0xf8,%P0" :: "i" (status) : "memory");
+}
+
+static __force_inline int _xtest(void)
+{
+  unsigned char out;
+  asm volatile (".byte 0x0f,0x01,0xd6 ; setnz %0" : "=r" (out) :: "memory");
+  return out;
+}
+
+#endif
+#endif
-- 
2.30.0