PERFORCE change 97913 for review

[Kip Macy]

http://perforce.freebsd.org/chv.cgi?CH=97913

Change 97913 by kmacy at kmacy_storage:sun4v_work on 2006/05/26 23:45:37

	Add Kris Kennaway's spinlock profiling

Affected files ...

.. //depot/projects/kmacy_sun4v/src/sys/conf/options#7 edit
.. //depot/projects/kmacy_sun4v/src/sys/kern/kern_mutex.c#5 edit
.. //depot/projects/kmacy_sun4v/src/sys/sys/lock.h#4 edit
.. //depot/projects/kmacy_sun4v/src/sys/sys/mutex.h#3 edit

Differences ...

==== //depot/projects/kmacy_sun4v/src/sys/conf/options#7 (text+ko) ====

@@ -512,6 +512,7 @@
 MUTEX_DEBUG		opt_global.h
 MUTEX_NOINLINE		opt_global.h
 MUTEX_PROFILING		opt_global.h
+SPIN_PROFILING		opt_global.h
 MSIZE			opt_global.h
 REGRESSION		opt_global.h
 RESTARTABLE_PANICS	opt_global.h

==== //depot/projects/kmacy_sun4v/src/sys/kern/kern_mutex.c#5 (text+ko) ====

@@ -116,6 +116,41 @@
 struct mtx sched_lock;
 struct mtx Giant;
 
+#ifdef SPIN_PROFILING
+SYSCTL_NODE(_debug, OID_AUTO, spinlock, CTLFLAG_RD, NULL, "spinlock debugging");
+SYSCTL_NODE(_debug_spinlock, OID_AUTO, prof, CTLFLAG_RD, NULL, "spinlock profiling");
+int spin_prof_enable = 0;
+SYSCTL_INT(_debug_spinlock_prof, OID_AUTO, enable, CTLFLAG_RW,
+    &spin_prof_enable, 0, "Enable tracing of spinlock holdtime");
+int spin_total = 0;
+int spin_count = 0;
+SYSCTL_INT(_debug_spinlock_prof, OID_AUTO, total, CTLFLAG_RD,
+    &spin_total, 0, "Number of spinlock spins recorded");
+SYSCTL_INT(_debug_spinlock_prof, OID_AUTO, count, CTLFLAG_RD,
+    &spin_count, 0, "Number of spinlock acquisitions recorded");
+
+static int
+reset_spin_prof_stats(SYSCTL_HANDLER_ARGS)
+{
+	int v = 0, error;
+
+	error = sysctl_handle_int(oidp, &v, 0, req);
+	if (error)
+		return (error);
+	if (req->newptr == NULL)
+		return (error);
+	if (v == 0)
+		return (0);
+
+	spin_total = 0;
+	spin_count = 0;
+	return (0);
+}
+
+SYSCTL_PROC(_debug_spinlock_prof, OID_AUTO, reset, CTLTYPE_INT | CTLFLAG_RW,
+    NULL, 0, reset_spin_prof_stats, "I", "Reset spinlock profiling statistics");
+#endif
+
 #ifdef MUTEX_PROFILING
 SYSCTL_NODE(_debug, OID_AUTO, mutex, CTLFLAG_RD, NULL, "mutex debugging");
 SYSCTL_NODE(_debug_mutex, OID_AUTO, prof, CTLFLAG_RD, NULL, "mutex profiling");
@@ -592,6 +627,12 @@
     int line)
 {
 	int i = 0;
+#ifdef SPIN_PROFILING
+	int profiling = 0;
+
+	if (m->mtx_object.lo_flags & LO_PROFILE && spin_prof_enable)
+		profiling = 1;
+#endif
 
 	if (LOCK_LOG_TEST(&m->mtx_object, opts))
 		CTR1(KTR_LOCK, "_mtx_lock_spin: %p spinning", m);
@@ -622,6 +663,13 @@
 		}
 		spinlock_enter();
 	}
+#ifdef SPIN_PROFILING
+	/* We have the lock, record how many spins it took to get it */
+	if (profiling) {
+	  	spin_total += i;
+		spin_count++;
+	}
+#endif
 
 	if (LOCK_LOG_TEST(&m->mtx_object, opts))
 		CTR1(KTR_LOCK, "_mtx_lock_spin: %p spin done", m);
@@ -849,6 +897,8 @@
 		flags |= LO_WITNESS;
 	if (opts & MTX_DUPOK)
 		flags |= LO_DUPOK;
+	if (opts & MTX_PROFILE)
+		flags |= LO_PROFILE;
 
 	/* Initialize mutex. */
 	m->mtx_lock = MTX_UNOWNED;
@@ -907,7 +957,7 @@
 	 * Initialize mutexes.
 	 */
 	mtx_init(&Giant, "Giant", NULL, MTX_DEF | MTX_RECURSE);
-	mtx_init(&sched_lock, "sched lock", NULL, MTX_SPIN | MTX_RECURSE);
+	mtx_init(&sched_lock, "sched lock", NULL, MTX_SPIN | MTX_RECURSE | MTX_PROFILE);
 	mtx_init(&proc0.p_mtx, "process lock", NULL, MTX_DEF | MTX_DUPOK);
 	mtx_init(&devmtx, "cdev", NULL, MTX_DEF);
 	mtx_lock(&Giant);

==== //depot/projects/kmacy_sun4v/src/sys/sys/lock.h#4 (text+ko) ====

@@ -69,6 +69,7 @@
 #define	LO_DUPOK	0x00400000	/* Don't check for duplicate acquires */
 #define	LO_ENROLLPEND	0x00800000	/* On the pending enroll list. */
 #define	LO_CLASSMASK	0x0f000000	/* Class index bitmask. */
+#define	LO_PROFILE	0x10000000	/* Enable per-lock profiling */
 
 /*
  * Lock classes are statically assigned an index into the gobal lock_classes

==== //depot/projects/kmacy_sun4v/src/sys/sys/mutex.h#3 (text+ko) ====

@@ -56,6 +56,7 @@
 #define MTX_SPIN	0x00000001	/* Spin lock (disables interrupts) */
 #define MTX_RECURSE	0x00000004	/* Option: lock allowed to recurse */
 #define	MTX_NOWITNESS	0x00000008	/* Don't do any witness checking. */
+#define	MTX_PROFILE	0x00000010	/* Enable spinlock profiling for this spin lock */
 
 /*
  * Option flags passed to certain lock/unlock routines, through the use
@@ -164,6 +165,9 @@
  */
 #ifndef _get_spin_lock
 #ifdef SMP
+#ifdef SPIN_PROFILING
+extern int spin_prof_enable;
+extern int spin_count;
 #define _get_spin_lock(mp, tid, opts, file, line) do {			\
 	uintptr_t _tid = (uintptr_t)(tid);				\
 									\
@@ -174,7 +178,22 @@
 		else							\
 			_mtx_lock_spin((mp), _tid, (opts), (file), (line)); \
 	}								\
+	else if ((mp)->mtx_object.lo_flags & LO_PROFILE && spin_prof_enable) \
+		spin_count++;						\
 } while (0)
+#else /* SPIN_PROFILING */
+#define _get_spin_lock(mp, tid, opts, file, line) do {			\
+	uintptr_t _tid = (uintptr_t)(tid);				\
+									\
+	spinlock_enter();						\
+	if (!_obtain_lock((mp), _tid)) {				\
+		if ((mp)->mtx_lock == _tid)				\
+			(mp)->mtx_recurse++;				\
+		else							\
+			_mtx_lock_spin((mp), _tid, (opts), (file), (line)); \
+	}								\
+} while (0)
+#endif /* SPIN_PROFILING */
 #else /* SMP */
 #define _get_spin_lock(mp, tid, opts, file, line) do {			\
 	uintptr_t _tid = (uintptr_t)(tid);				\