nptl: Eliminate <smp.h> and __is_smp

Most systems are SMP, so optimizing for the UP case is no longer
approriate.  A dynamic check based on the kernel identification
has been only implemented for i386 anyway.

To disable adaptive mutexes on sh, define DEFAULT_ADAPTIVE_COUNT
as zero for this architecture.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

6 files changed, 0 insertions, 43 deletions

diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c
index 95c60a524a..4aa1231bec 100644
--- a/nptl/nptl-init.c
+++ b/nptl/nptl-init.c
@@ -32,7 +32,6 @@
 #include <fork.h>
 #include <version.h>
 #include <shlib-compat.h>
-#include <smp.h>
 #include <lowlevellock.h>
 #include <futex-internal.h>
 #include <kernel-features.h>
@@ -346,9 +345,6 @@ __pthread_initialize_minimal_internal (void)
     __libc_pthread_init (&__fork_generation, __reclaim_stacks,
 			 ptr_pthread_functions);
 
-  /* Determine whether the machine is SMP or not.  */
-  __is_smp = is_smp_system ();
-
 #if HAVE_TUNABLES
   __pthread_tunables_init ();
 #endif
diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h
index 710b21e890..686f54aa93 100644
--- a/nptl/pthreadP.h
+++ b/nptl/pthreadP.h
@@ -208,9 +208,6 @@ extern void __default_pthread_attr_freeres (void) attribute_hidden;
 extern size_t __static_tls_size attribute_hidden;
 extern size_t __static_tls_align_m1 attribute_hidden;
 
-/* Flag whether the machine is SMP or not.  */
-extern int __is_smp attribute_hidden;
-
 /* Thread descriptor handling.  */
 extern list_t __stack_user;
 hidden_proto (__stack_user)
diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c
index 7858abd528..fac774e608 100644
--- a/nptl/pthread_mutex_lock.c
+++ b/nptl/pthread_mutex_lock.c
@@ -120,9 +120,6 @@ __pthread_mutex_lock (pthread_mutex_t *mutex)
   else if (__builtin_expect (PTHREAD_MUTEX_TYPE (mutex)
 			  == PTHREAD_MUTEX_ADAPTIVE_NP, 1))
     {
-      if (! __is_smp)
-	goto simple;
-
       if (LLL_MUTEX_TRYLOCK (mutex) != 0)
 	{
 	  int cnt = 0;
diff --git a/nptl/pthread_mutex_timedlock.c b/nptl/pthread_mutex_timedlock.c
index fe9e651f6c..de88e9fc25 100644
--- a/nptl/pthread_mutex_timedlock.c
+++ b/nptl/pthread_mutex_timedlock.c
@@ -113,9 +113,6 @@ __pthread_mutex_clocklock_common (pthread_mutex_t *mutex,
 
 
     case PTHREAD_MUTEX_ADAPTIVE_NP:
-      if (! __is_smp)
-	goto simple;
-
       if (lll_trylock (mutex->__data.__lock) != 0)
 	{
 	  int cnt = 0;
diff --git a/nptl/smp.h b/nptl/smp.h
deleted file mode 100644
index 537e5e945c..0000000000
--- a/nptl/smp.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/* Determine whether the host has multiple processors.  Stub version.
-   Copyright (C) 1996-2020 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 Library General Public License as
-   published by the Free Software Foundation; either version 2 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
-   Library General Public License for more details.
-
-   You should have received a copy of the GNU Library General Public
-   License along with the GNU C Library; see the file COPYING.LIB.  If
-   not, see <https://www.gnu.org/licenses/>.  */
-
-/* Test whether the machine has more than one processor.  This is not the
-   best test but good enough.  More complicated tests would require `malloc'
-   which is not available at that time.  */
-static inline int
-is_smp_system (void)
-{
-  /* Assume all machines are SMP and/or CMT and/or SMT.  */
-  return 1;
-}
diff --git a/nptl/vars.c b/nptl/vars.c
index 3696020145..2f52391dc2 100644
--- a/nptl/vars.c
+++ b/nptl/vars.c
@@ -27,9 +27,6 @@ union pthread_attr_transparent __default_pthread_attr attribute_hidden;
 /* Mutex protecting __default_pthread_attr.  */
 int __default_pthread_attr_lock = LLL_LOCK_INITIALIZER;
 
-/* Flag whether the machine is SMP or not.  */
-int __is_smp attribute_hidden;
-
 #ifndef TLS_MULTIPLE_THREADS_IN_TCB
 /* Variable set to a nonzero value either if more than one thread runs or ran,
    or if a single-threaded process is trying to cancel itself.  See