Change and clean the mutex lock interface.

mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)

1 files changed, 24 insertions, 24 deletions

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index a72de0e..deee375 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -186,9 +186,9 @@ CURSIG(struct proc *p)
 	SIGSETNAND(tmpset, p->p_sigmask);
 	if (SIGISEMPTY(tmpset) && (p->p_flag & P_TRACED) == 0)
 		return (0);
-	mtx_enter(&Giant, MTX_DEF);
+	mtx_lock(&Giant);
 	r = issignal(p);
-	mtx_exit(&Giant, MTX_DEF);
+	mtx_unlock(&Giant);
 	return (r);
 }
 
@@ -1087,11 +1087,11 @@ psignal(p, sig)
 			action = SIG_DFL;
 	}
 
-	mtx_enter(&sched_lock, MTX_SPIN);
+	mtx_lock_spin(&sched_lock);
 	if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
 	    (p->p_flag & P_TRACED) == 0)
 		p->p_nice = NZERO;
-	mtx_exit(&sched_lock, MTX_SPIN);
+	mtx_unlock_spin(&sched_lock);
 
 	if (prop & SA_CONT)
 		SIG_STOPSIGMASK(p->p_siglist);
@@ -1116,9 +1116,9 @@ psignal(p, sig)
 	 * Defer further processing for signals which are held,
 	 * except that stopped processes must be continued by SIGCONT.
 	 */
-	mtx_enter(&sched_lock, MTX_SPIN);
+	mtx_lock_spin(&sched_lock);
 	if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP)) {
-		mtx_exit(&sched_lock, MTX_SPIN);
+		mtx_unlock_spin(&sched_lock);
 		PROC_UNLOCK(p);
 		return;
 	}
@@ -1132,7 +1132,7 @@ psignal(p, sig)
 		 * trap() or syscall().
 		 */
 		if ((p->p_sflag & PS_SINTR) == 0) {
-			mtx_exit(&sched_lock, MTX_SPIN);
+			mtx_unlock_spin(&sched_lock);
 			goto out;
 		}
 		/*
@@ -1142,7 +1142,7 @@ psignal(p, sig)
 		 */
 		if (p->p_flag & P_TRACED)
 			goto run;
-		mtx_exit(&sched_lock, MTX_SPIN);
+		mtx_unlock_spin(&sched_lock);
 		/*
 		 * If SIGCONT is default (or ignored) and process is
 		 * asleep, we are finished; the process should not
@@ -1182,7 +1182,7 @@ psignal(p, sig)
 		/* NOTREACHED */
 
 	case SSTOP:
-		mtx_exit(&sched_lock, MTX_SPIN);
+		mtx_unlock_spin(&sched_lock);
 		/*
 		 * If traced process is already stopped,
 		 * then no further action is necessary.
@@ -1211,11 +1211,11 @@ psignal(p, sig)
 				SIGDELSET(p->p_siglist, sig);
 			if (action == SIG_CATCH)
 				goto runfast;
-			mtx_enter(&sched_lock, MTX_SPIN);
+			mtx_lock_spin(&sched_lock);
 			if (p->p_wchan == NULL)
 				goto run;
 			p->p_stat = SSLEEP;
-			mtx_exit(&sched_lock, MTX_SPIN);
+			mtx_unlock_spin(&sched_lock);
 			goto out;
 		}
 
@@ -1234,14 +1234,14 @@ psignal(p, sig)
 		 * runnable and can look at the signal.  But don't make
 		 * the process runnable, leave it stopped.
 		 */
-		mtx_enter(&sched_lock, MTX_SPIN);
+		mtx_lock_spin(&sched_lock);
 		if (p->p_wchan && p->p_sflag & PS_SINTR) {
 			if (p->p_sflag & PS_CVWAITQ)
 				cv_waitq_remove(p);
 			else
 				unsleep(p);
 		}
-		mtx_exit(&sched_lock, MTX_SPIN);
+		mtx_unlock_spin(&sched_lock);
 		goto out;
 
 	default:
@@ -1251,17 +1251,17 @@ psignal(p, sig)
 		 * It will either never be noticed, or noticed very soon.
 		 */
 		if (p == curproc) {
-			mtx_exit(&sched_lock, MTX_SPIN);
+			mtx_unlock_spin(&sched_lock);
 			signotify(p);
 		}
 #ifdef SMP
 		else if (p->p_stat == SRUN) {
-			mtx_exit(&sched_lock, MTX_SPIN);
+			mtx_unlock_spin(&sched_lock);
 			forward_signal(p);
 		}
 #endif
 		else
-			mtx_exit(&sched_lock, MTX_SPIN);
+			mtx_unlock_spin(&sched_lock);
 		goto out;
 	}
 	/*NOTREACHED*/
@@ -1270,14 +1270,14 @@ runfast:
 	/*
 	 * Raise priority to at least PUSER.
 	 */
-	mtx_enter(&sched_lock, MTX_SPIN);
+	mtx_lock_spin(&sched_lock);
 	if (p->p_priority > PUSER)
 		p->p_priority = PUSER;
 run:
 	/* If we jump here, sched_lock has to be owned. */
 	mtx_assert(&sched_lock, MA_OWNED | MA_NOTRECURSED);
 	setrunnable(p);
-	mtx_exit(&sched_lock, MTX_SPIN);
+	mtx_unlock_spin(&sched_lock);
 out:
 	/* If we jump here, sched_lock should not be owned. */
 	mtx_assert(&sched_lock, MA_NOTOWNED);
@@ -1336,10 +1336,10 @@ issignal(p)
 			do {
 				stop(p);
 				PROCTREE_LOCK(PT_RELEASE);
-				mtx_enter(&sched_lock, MTX_SPIN);
+				mtx_lock_spin(&sched_lock);
 				DROP_GIANT_NOSWITCH();
 				mi_switch();
-				mtx_exit(&sched_lock, MTX_SPIN);
+				mtx_unlock_spin(&sched_lock);
 				PICKUP_GIANT();
 				PROCTREE_LOCK(PT_SHARED);
 			} while (!trace_req(p)
@@ -1413,10 +1413,10 @@ issignal(p)
 				if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
 					psignal(p->p_pptr, SIGCHLD);
 				PROCTREE_LOCK(PT_RELEASE);
-				mtx_enter(&sched_lock, MTX_SPIN);
+				mtx_lock_spin(&sched_lock);
 				DROP_GIANT_NOSWITCH();
 				mi_switch();
-				mtx_exit(&sched_lock, MTX_SPIN);
+				mtx_unlock_spin(&sched_lock);
 				PICKUP_GIANT();
 				break;
 			} else if (prop & SA_IGNORE) {
@@ -1464,11 +1464,11 @@ stop(p)
 {
 
 	PROCTREE_ASSERT(PT_SHARED);
-	mtx_enter(&sched_lock, MTX_SPIN);
+	mtx_lock_spin(&sched_lock);
 	p->p_stat = SSTOP;
 	p->p_flag &= ~P_WAITED;
 	wakeup((caddr_t)p->p_pptr);
-	mtx_exit(&sched_lock, MTX_SPIN);
+	mtx_unlock_spin(&sched_lock);
 }
 
 /*