From: mpi <mpi@openbsd.org>
Date: Mon, 29 May 2017 14:47:54 +0000 (+0000)
Subject: SPINLOCK_SPIN_HOOK is no more, define our own set of macros.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=ad36c4aee20b7adfcb453d0a0ca6a5c80dd47115;p=openbsd

SPINLOCK_SPIN_HOOK is no more, define our own set of macros.

Prodded by kettenis@ and tedu@
---

diff --git a/lib/librthread/rthread_mutex.c b/lib/librthread/rthread_mutex.c
index 9ee8f1b75af..ea2db8131b3 100644
--- a/lib/librthread/rthread_mutex.c
+++ b/lib/librthread/rthread_mutex.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rthread_mutex.c,v 1.2 2017/05/28 09:45:25 mpi Exp $ */
+/*	$OpenBSD: rthread_mutex.c,v 1.3 2017/05/29 14:47:54 mpi Exp $ */
 /*
  * Copyright (c) 2017 Martin Pieuchot <mpi@openbsd.org>
  * Copyright (c) 2012 Philip Guenther <guenther@openbsd.org>
@@ -38,6 +38,13 @@ enum {
 	CONTENDED = 2,	/* threads waiting for this mutex */
 };
 
+#define SPIN_COUNT	128
+#if defined(__i386__) || defined(__amd64__)
+#define SPIN_WAIT()	asm volatile("pause": : : "memory")
+#else
+#define SPIN_WAIT()	do { } while (0)
+#endif
+
 static _atomic_lock_t static_init_lock = _SPINLOCK_UNLOCKED;
 
 int
@@ -164,11 +171,11 @@ _rthread_mutex_timedlock(pthread_mutex_t *mutexp, int trywait,
 		return (error);
 
 	/* Try hard to not enter the kernel. */
-	for (i = 0; i < SPINLOCK_SPIN_COUNT; i ++) {
+	for (i = 0; i < SPIN_COUNT; i ++) {
 		if (mutex->lock == UNLOCKED)
 			break;
 
-		SPINLOCK_SPIN_HOOK;
+		SPIN_WAIT();
 	}
 
 	lock = atomic_cas_uint(&mutex->lock, UNLOCKED, LOCKED);
diff --git a/lib/librthread/synch.h b/lib/librthread/synch.h
index 8f3f241c2f7..0c69a39164e 100644
--- a/lib/librthread/synch.h
+++ b/lib/librthread/synch.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: synch.h,v 1.1 2017/05/27 14:20:39 mpi Exp $ */
+/*	$OpenBSD: synch.h,v 1.2 2017/05/29 14:47:54 mpi Exp $ */
 /*
  * Copyright (c) 2017 Martin Pieuchot
  *
@@ -21,9 +21,6 @@
 
 REDIRECT_SYSCALL(futex);
 
-#include <machine/lock.h>	/* for SPINLOCK_SPIN_HOOK */
-#define SPINLOCK_SPIN_COUNT	128
-
 static inline int
 _wake(volatile uint32_t *p, int n)
 {