Add a new command, show lockstat, which shows statistics of locks

Currently the command shows the number of allocated locks.

The command is useful only if LOCKDEBUG is enabled.

share/man/man4/ddb.4

@@ -1,4 +1,4 @@
-.\"	$NetBSD: ddb.4,v 1.174 2018/02/19 10:31:53 wiz Exp $
+.\"	$NetBSD: ddb.4,v 1.175 2018/03/16 04:37:55 ozaki-r Exp $
 .\"
 .\" Copyright (c) 1997 - 2009 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -56,7 +56,7 @@
 .\" any improvements or extensions that they make and grant Carnegie Mellon
 .\" the rights to redistribute these changes.
 .\"
-.Dd February 17, 2018
+.Dd March 16, 2018
 .Dt DDB 4
 .Os
 .Sh NAME
@@ -650,6 +650,10 @@ Display information about a lock at
 .Ar address .
 This command is useful only if a kernel is compiled with
 .Cd options LOCKDEBUG .
+.It Ic show lockstat
+Display information about statistics of locks.
+This command is useful only if a kernel is compiled with
+.Cd options LOCKDEBUG .
 .It Ic show map Ns Oo Cm /f Oc Ar address
 Print the vm_map at
 .Ar address .

sys/ddb/db_command.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: db_command.c,v 1.149 2018/03/04 07:14:50 mlelstv Exp $	*/
+/*	$NetBSD: db_command.c,v 1.150 2018/03/16 04:37:55 ozaki-r Exp $	*/
 
 /*
  * Copyright (c) 1996, 1997, 1998, 1999, 2002, 2009 The NetBSD Foundation, Inc.
@@ -60,7 +60,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: db_command.c,v 1.149 2018/03/04 07:14:50 mlelstv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: db_command.c,v 1.150 2018/03/16 04:37:55 ozaki-r Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_aio.h"
@@ -190,6 +190,7 @@ static void	db_event_print_cmd(db_expr_t, bool, db_expr_t, const char *);
 static void	db_fncall(db_expr_t, bool, db_expr_t, const char *);
 static void     db_help_print_cmd(db_expr_t, bool, db_expr_t, const char *);
 static void	db_lock_print_cmd(db_expr_t, bool, db_expr_t, const char *);
+static void	db_show_lockstat(db_expr_t, bool, db_expr_t, const char *);
 static void	db_mount_print_cmd(db_expr_t, bool, db_expr_t, const char *);
 static void	db_mbuf_print_cmd(db_expr_t, bool, db_expr_t, const char *);
 static void	db_map_print_cmd(db_expr_t, bool, db_expr_t, const char *);
@@ -248,6 +249,9 @@ static const struct db_command db_show_cmds[] = {
 	    "Print the files open by process at address",
 	    "[/f] address", NULL) },
 	{ DDB_ADD_CMD("lock",	db_lock_print_cmd,	0,NULL,NULL,NULL) },
+	{ DDB_ADD_CMD("lockstat",
+				db_show_lockstat,	0,
+	    "Print statistics of locks", NULL, NULL) },
 	{ DDB_ADD_CMD("map",	db_map_print_cmd,	0,
 	    "Print the vm_map at address.", "[/f] address",NULL) },
 	{ DDB_ADD_CMD("module", db_show_module_cmd,	0,
@@ -1226,6 +1230,16 @@ db_lock_print_cmd(db_expr_t addr, bool have_addr,
 #endif
 }
 
+static void
+db_show_lockstat(db_expr_t addr, bool have_addr,
+    db_expr_t count, const char *modif)
+{
+
+#ifdef _KERNEL	/* XXX CRASH(8) */
+	lockdebug_show_lockstat(db_printf);
+#endif
+}
+
 /*
  * Call random function:
  * !expr(arg,arg,arg)

sys/kern/subr_lockdebug.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: subr_lockdebug.c,v 1.60 2018/02/20 03:34:52 ozaki-r Exp $	*/
+/*	$NetBSD: subr_lockdebug.c,v 1.61 2018/03/16 04:43:37 ozaki-r Exp $	*/
 
 /*-
  * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -34,7 +34,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_lockdebug.c,v 1.60 2018/02/20 03:34:52 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_lockdebug.c,v 1.61 2018/03/16 04:43:37 ozaki-r Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -838,6 +838,56 @@ lockdebug_lock_print(void *addr, void (*pr)(const char *, ...))
 	(*pr)("Sorry, kernel not built with the LOCKDEBUG option.\n");
 #endif	/* LOCKDEBUG */
 }
+
+void
+lockdebug_show_lockstat(void (*pr)(const char *, ...))
+{
+#ifdef LOCKDEBUG
+	lockdebug_t *ld;
+	void *_ld;
+	uint32_t n_null = 0;
+	uint32_t n_spin_mutex = 0;
+	uint32_t n_adaptive_mutex = 0;
+	uint32_t n_rwlock = 0;
+	uint32_t n_cv = 0;
+	uint32_t n_others = 0;
+
+	RB_TREE_FOREACH(_ld, &ld_rb_tree) {
+		ld = _ld;
+		if (ld->ld_lock == NULL) {
+			n_null++;
+			continue;
+		}
+		if (ld->ld_lockops->lo_type == LOCKOPS_CV) {
+			n_cv++;
+			continue;
+		}
+		if (ld->ld_lockops->lo_name[0] == 'M') {
+			if (ld->ld_lockops->lo_type == LOCKOPS_SLEEP)
+				n_adaptive_mutex++;
+			else
+				n_spin_mutex++;
+			continue;
+		}
+		if (ld->ld_lockops->lo_name[0] == 'R') {
+			n_rwlock++;
+			continue;
+		}
+		n_others++;
+	}
+	(*pr)(
+	    "condvar: %u\n"
+	    "spin mutex: %u\n"
+	    "adaptive mutex: %u\n"
+	    "rwlock: %u\n"
+	    "null locks: %u\n"
+	    "others: %u\n",
+	    n_cv,  n_spin_mutex, n_adaptive_mutex, n_rwlock,
+	    n_null, n_others);
+#else
+	(*pr)("Sorry, kernel not built with the LOCKDEBUG option.\n");
+#endif	/* LOCKDEBUG */
+}
 #endif	/* DDB */
 
 /*

sys/sys/lockdebug.h

@@ -1,4 +1,4 @@
-/*	$NetBSD: lockdebug.h,v 1.16 2017/09/16 23:54:41 christos Exp $	*/
+/*	$NetBSD: lockdebug.h,v 1.17 2018/03/16 04:37:55 ozaki-r Exp $	*/
 
 /*-
  * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -58,6 +58,7 @@ void	lockdebug_abort(const char *, size_t, const volatile void *,
 
 void	lockdebug_lock_print(void *, void (*)(const char *, ...)
     __printflike(1, 2));
+void	lockdebug_show_lockstat(void (*)(const char *, ...) __printflike(1, 2));
 
 #ifdef LOCKDEBUG