Add the OpenSolaris dtrace lockstat provider. The lockstat provider

adds probes for mutexes, reader/writer and shared/exclusive locks to
gather contention statistics and other locking information for
dtrace scripts, the lockstat(1M) command and other potential
consumers.

Reviewed by:	attilio jhb jb
Approved by:	gnn (mentor)

1 files changed, 64 insertions, 0 deletions

diff --git a/sys/kern/kern_lockstat.c b/sys/kern/kern_lockstat.c
new file mode 100644
index 0000000..1f35893
--- /dev/null
+++ b/sys/kern/kern_lockstat.c
@@ -0,0 +1,64 @@
+/*-
+ * Copyright 2008-2009 Stacey Son <sson@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Backend for the lock tracing (lockstat) kernel support. This is required 
+ * to allow a module to load even though DTrace kernel support may not be 
+ * present. 
+ *
+ */
+
+#include "opt_kdtrace.h"
+
+#ifdef KDTRACE_HOOKS
+
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/lockstat.h>
+
+/*
+ * The following must match the type definition of dtrace_probe.  It is  
+ * defined this way to avoid having to rely on CDDL code.
+ */
+uint32_t lockstat_probemap[LS_NPROBES];
+void (*lockstat_probe_func)(uint32_t, uintptr_t, uintptr_t,
+    uintptr_t, uintptr_t, uintptr_t);
+
+
+uint64_t 
+lockstat_nsecs(void)
+{
+	struct bintime bt;
+	uint64_t ns;
+
+	binuptime(&bt);
+	ns = bt.sec * (uint64_t)1000000000;
+	ns += ((uint64_t)1000000000 * (uint32_t)(bt.frac >> 32)) >> 32;
+	return (ns);
+}
+
+#endif /* KDTRACE_HOOKS */