[src/trunk]: src/lib/libpthread Add a pthread__smt_wake and add support for i...

[matt <matt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/599a836a4f6a
branches:  trunk
changeset: 781038:599a836a4f6a
user:      matt <matt%NetBSD.org@localhost>
date:      Thu Aug 16 04:49:47 2012 +0000

description:
Add a pthread__smt_wake and add support for it on arm along with
pthread__smt_pause.  These are implemented using the ARM instructions
SEV (wake) and WFE (pause).  These are treated as NOPs on ARM CPUs that
don't support them.

diffstat:

 lib/libpthread/arch/arm/pthread_md.h |  5 ++++-
 lib/libpthread/pthread_int.h         |  5 ++++-
 lib/libpthread/pthread_mutex.c       |  9 ++++++---
 lib/libpthread/pthread_spin.c        |  5 +++--
 4 files changed, 17 insertions(+), 7 deletions(-)

diffs (102 lines):

diff -r 930db33c61a1 -r 599a836a4f6a lib/libpthread/arch/arm/pthread_md.h
--- a/lib/libpthread/arch/arm/pthread_md.h      Thu Aug 16 00:40:28 2012 +0000
+++ b/lib/libpthread/arch/arm/pthread_md.h      Thu Aug 16 04:49:47 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pthread_md.h,v 1.6 2011/01/25 19:12:04 christos Exp $  */
+/*     $NetBSD: pthread_md.h,v 1.7 2012/08/16 04:49:48 matt Exp $      */
 
 /*
  * Copyright (c) 2001 Wasabi Systems, Inc.
@@ -49,6 +49,9 @@
        return (ret);
 }
 
+#define pthread__smt_pause()   __asm __volatile("wfe")
+#define pthread__smt_wake()    __asm __volatile("sev")
+
 #define        pthread__uc_sp(ucp)     ((ucp)->uc_mcontext.__gregs[_REG_SP])
 
 /*
diff -r 930db33c61a1 -r 599a836a4f6a lib/libpthread/pthread_int.h
--- a/lib/libpthread/pthread_int.h      Thu Aug 16 00:40:28 2012 +0000
+++ b/lib/libpthread/pthread_int.h      Thu Aug 16 04:49:47 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pthread_int.h,v 1.85 2012/05/04 12:26:33 joerg Exp $   */
+/*     $NetBSD: pthread_int.h,v 1.86 2012/08/16 04:49:47 matt Exp $    */
 
 /*-
  * Copyright (c) 2001, 2002, 2003, 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -299,6 +299,9 @@
 #ifndef pthread__smt_pause
 #define        pthread__smt_pause()    /* nothing */
 #endif
+#ifndef pthread__smt_wake
+#define        pthread__smt_wake()     /* nothing */
+#endif
 
 /*
  * Bits in the owner field of the lock that indicate lock state.  If the
diff -r 930db33c61a1 -r 599a836a4f6a lib/libpthread/pthread_mutex.c
--- a/lib/libpthread/pthread_mutex.c    Thu Aug 16 00:40:28 2012 +0000
+++ b/lib/libpthread/pthread_mutex.c    Thu Aug 16 04:49:47 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pthread_mutex.c,v 1.53 2012/03/13 01:05:55 joerg Exp $ */
+/*     $NetBSD: pthread_mutex.c,v 1.54 2012/08/16 04:49:47 matt Exp $  */
 
 /*-
  * Copyright (c) 2001, 2003, 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -47,7 +47,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: pthread_mutex.c,v 1.53 2012/03/13 01:05:55 joerg Exp $");
+__RCSID("$NetBSD: pthread_mutex.c,v 1.54 2012/08/16 04:49:47 matt Exp $");
 
 #include <sys/types.h>
 #include <sys/lwpctl.h>
@@ -379,8 +379,10 @@
 #endif
        self = pthread__self();
        value = atomic_cas_ptr_ni(&ptm->ptm_owner, self, NULL);
-       if (__predict_true(value == self))
+       if (__predict_true(value == self)) {
+               pthread__smt_wake();
                return 0;
+       }
        return pthread__mutex_unlock_slow(ptm);
 }
 
@@ -475,6 +477,7 @@
         * are dependent upon 'thread'.
         */
        thread = atomic_swap_ptr(&ptm->ptm_waiters, NULL);
+       pthread__smt_wake();
 
        for (;;) {
                /*
diff -r 930db33c61a1 -r 599a836a4f6a lib/libpthread/pthread_spin.c
--- a/lib/libpthread/pthread_spin.c     Thu Aug 16 00:40:28 2012 +0000
+++ b/lib/libpthread/pthread_spin.c     Thu Aug 16 04:49:47 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pthread_spin.c,v 1.5 2008/04/28 20:23:01 martin Exp $  */
+/*     $NetBSD: pthread_spin.c,v 1.6 2012/08/16 04:49:47 matt Exp $    */
 
 /*-
  * Copyright (c) 2001, 2006, 2007 The NetBSD Foundation, Inc.
@@ -34,7 +34,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: pthread_spin.c,v 1.5 2008/04/28 20:23:01 martin Exp $");
+__RCSID("$NetBSD: pthread_spin.c,v 1.6 2012/08/16 04:49:47 matt Exp $");
 
 #include <sys/types.h>
 #include <sys/ras.h>
@@ -133,6 +133,7 @@
 
        self = pthread__self();
        pthread__spinunlock(self, &lock->pts_spin);
+       pthread__smt_wake();
 
        return 0;
 }