Index: sys/kern/subr_witness.c
===================================================================
--- sys/kern/subr_witness.c	(wersja 215409)
+++ sys/kern/subr_witness.c	(kopia robocza)
@@ -425,6 +425,11 @@
 SYSCTL_INT(_debug_witness, OID_AUTO, skipspin, CTLFLAG_RDTUN, &witness_skipspin,
     0, "");
 
+static int witness_do_checkorder = 1;
+TUNABLE_INT("debug.witness.checkorder", &witness_do_checkorder);
+SYSCTL_INT(_debug_witness, OID_AUTO, checkorder, CTLFLAG_RW,
+    &witness_do_checkorder, 0, "");
+
 /*
  * Call this to print out the relations between locks.
  */
@@ -1046,8 +1051,9 @@
 	struct thread *td;
 	int i, j;
 
-	if (witness_cold || witness_watch < 1 || lock->lo_witness == NULL ||
-	    panicstr != NULL)
+	if (witness_cold || witness_watch < 1 || !witness_do_checkorder ||
+	    lock->lo_witness == NULL ||
+	    (lock->lo_flags & LO_NOORDERCHECK) != 0 || panicstr != NULL)
 		return;
 
 	w = lock->lo_witness;
Index: sys/kern/kern_mutex.c
===================================================================
--- sys/kern/kern_mutex.c	(wersja 215409)
+++ sys/kern/kern_mutex.c	(kopia robocza)
@@ -780,7 +780,8 @@
 	int flags;
 
 	MPASS((opts & ~(MTX_SPIN | MTX_QUIET | MTX_RECURSE |
-		MTX_NOWITNESS | MTX_DUPOK | MTX_NOPROFILE)) == 0);
+		MTX_NOWITNESS | MTX_DUPOK | MTX_NOPROFILE |
+		MTX_NOORDERCHECK)) == 0);
 	ASSERT_ATOMIC_LOAD_PTR(m->mtx_lock,
 	    ("%s: mtx_lock not aligned for %s: %p", __func__, name,
 	    &m->mtx_lock));
@@ -806,6 +807,8 @@
 		flags |= LO_DUPOK;
 	if (opts & MTX_NOPROFILE)
 		flags |= LO_NOPROFILE;
+	if (opts & MTX_NOORDERCHECK)
+		flags |= LO_NOORDERCHECK;
 
 	/* Initialize mutex. */
 	m->mtx_lock = MTX_UNOWNED;
Index: sys/kern/kern_rwlock.c
===================================================================
--- sys/kern/kern_rwlock.c	(wersja 215409)
+++ sys/kern/kern_rwlock.c	(kopia robocza)
@@ -173,7 +173,7 @@
 	int flags;
 
 	MPASS((opts & ~(RW_DUPOK | RW_NOPROFILE | RW_NOWITNESS | RW_QUIET |
-	    RW_RECURSE)) == 0);
+	    RW_RECURSE | RW_NOORDERCHECK)) == 0);
 	ASSERT_ATOMIC_LOAD_PTR(rw->rw_lock,
 	    ("%s: rw_lock not aligned for %s: %p", __func__, name,
 	    &rw->rw_lock));
@@ -189,6 +189,8 @@
 		flags |= LO_RECURSABLE;
 	if (opts & RW_QUIET)
 		flags |= LO_QUIET;
+	if (opts & RW_NOORDERCHECK)
+		flags |= LO_NOORDERCHECK;
 
 	rw->rw_lock = RW_UNLOCKED;
 	rw->rw_recurse = 0;
Index: sys/kern/kern_sx.c
===================================================================
--- sys/kern/kern_sx.c	(wersja 215409)
+++ sys/kern/kern_sx.c	(kopia robocza)
@@ -204,7 +204,7 @@
 	int flags;
 
 	MPASS((opts & ~(SX_QUIET | SX_RECURSE | SX_NOWITNESS | SX_DUPOK |
-	    SX_NOPROFILE | SX_NOADAPTIVE)) == 0);
+	    SX_NOPROFILE | SX_NOADAPTIVE | SX_NOORDERCHECK)) == 0);
 	ASSERT_ATOMIC_LOAD_PTR(sx->sx_lock,
 	    ("%s: sx_lock not aligned for %s: %p", __func__, description,
 	    &sx->sx_lock));
@@ -220,6 +220,8 @@
 		flags |= LO_RECURSABLE;
 	if (opts & SX_QUIET)
 		flags |= LO_QUIET;
+	if (opts & SX_NOORDERCHECK)
+		flags |= LO_NOORDERCHECK;
 
 	flags |= opts & SX_NOADAPTIVE;
 	sx->sx_lock = SX_LOCK_UNLOCKED;
Index: sys/kern/kern_lock.c
===================================================================
--- sys/kern/kern_lock.c	(wersja 215409)
+++ sys/kern/kern_lock.c	(kopia robocza)
@@ -385,6 +385,8 @@
 		iflags |= LO_WITNESS;
 	if (flags & LK_QUIET)
 		iflags |= LO_QUIET;
+	if (flags & LK_NOORDERCHECK)
+		iflags |= LO_NOORDERCHECK;
 	iflags |= flags & (LK_ADAPTIVE | LK_NOSHARE);
 
 	lk->lk_lock = LK_UNLOCKED;
Index: sys/kern/kern_rmlock.c
===================================================================
--- sys/kern/kern_rmlock.c	(wersja 215409)
+++ sys/kern/kern_rmlock.c	(kopia robocza)
@@ -198,6 +198,8 @@
 		liflags |= LO_WITNESS;
 	if (opts & RM_RECURSE)
 		liflags |= LO_RECURSABLE;
+	if (opts & RM_NOORDERCHECK)
+		liflags |= LO_NOORDERCHECK;
 	rm->rm_writecpus = all_cpus;
 	LIST_INIT(&rm->rm_activeReaders);
 	if (opts & RM_SLEEPABLE) {
Index: sys/sys/sx.h
===================================================================
--- sys/sys/sx.h	(wersja 215409)
+++ sys/sys/sx.h	(kopia robocza)
@@ -260,6 +260,7 @@
 #define	SX_QUIET		0x08
 #define	SX_NOADAPTIVE		0x10
 #define	SX_RECURSE		0x20
+#define	SX_NOORDERCHECK		0x40
 
 /*
  * Options passed to sx_*lock_hard().
Index: sys/sys/rwlock.h
===================================================================
--- sys/sys/rwlock.h	(wersja 215409)
+++ sys/sys/rwlock.h	(kopia robocza)
@@ -218,6 +218,7 @@
 #define	RW_NOWITNESS	0x04
 #define	RW_QUIET	0x08
 #define	RW_RECURSE	0x10
+#define	RW_NOORDERCHECK	0x20
 
 /*
  * The INVARIANTS-enabled rw_assert() functionality.
Index: sys/sys/lock.h
===================================================================
--- sys/sys/lock.h	(wersja 215409)
+++ sys/sys/lock.h	(kopia robocza)
@@ -79,6 +79,7 @@
 #define	LO_SLEEPABLE	0x00100000	/* Lock may be held while sleeping. */
 #define	LO_UPGRADABLE	0x00200000	/* Lock may be upgraded/downgraded. */
 #define	LO_DUPOK	0x00400000	/* Don't check for duplicate acquires */
+#define	LO_NOORDERCHECK	0x00800000	/* Don't check order in witness. */
 #define	LO_CLASSMASK	0x0f000000	/* Class index bitmask. */
 #define LO_NOPROFILE    0x10000000      /* Don't profile this lock */
 
Index: sys/sys/lockmgr.h
===================================================================
--- sys/sys/lockmgr.h	(wersja 215409)
+++ sys/sys/lockmgr.h	(kopia robocza)
@@ -146,6 +146,7 @@
 #define	LK_NOWITNESS	0x000010
 #define	LK_QUIET	0x000020
 #define	LK_ADAPTIVE	0x000040
+#define	LK_NOORDERCHECK	0x000080
 
 /*
  * Additional attributes to be used in lockmgr().
Index: sys/sys/rmlock.h
===================================================================
--- sys/sys/rmlock.h	(wersja 215409)
+++ sys/sys/rmlock.h	(kopia robocza)
@@ -45,6 +45,7 @@
 #define	RM_NOWITNESS	0x00000001
 #define	RM_RECURSE	0x00000002
 #define	RM_SLEEPABLE	0x00000004
+#define	RM_NOORDERCHECK	0x00000008
 
 void	rm_init(struct rmlock *rm, const char *name);
 void	rm_init_flags(struct rmlock *rm, const char *name, int opts);
Index: sys/sys/mutex.h
===================================================================
--- sys/sys/mutex.h	(wersja 215409)
+++ sys/sys/mutex.h	(kopia robocza)
@@ -52,6 +52,7 @@
 #define MTX_RECURSE	0x00000004	/* Option: lock allowed to recurse */
 #define	MTX_NOWITNESS	0x00000008	/* Don't do any witness checking. */
 #define MTX_NOPROFILE   0x00000020	/* Don't profile this lock */
+#define	MTX_NOORDERCHECK 0x00000040	/* Don't check order in witness. */
 
 /*
  * Option flags passed to certain lock/unlock routines, through the use
Index: share/man/man4/witness.4
===================================================================
--- share/man/man4/witness.4	(wersja 215409)
+++ share/man/man4/witness.4	(kopia robocza)
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd February 18, 2001
+.Dd January 7, 2011
 .Dt WITNESS 4
 .Os
 .Sh NAME
@@ -104,6 +104,13 @@
 can be set via
 .Xr loader 8 .
 .Pp
+The sysctl
+.Va debug.witness.checkorder
+allows to disable lock ordering problems checking and reporting.
+All lock operations are still recorder, which allows to obtain useful data from
+.Xr ddb 4
+witness commands.
+.Pp
 The
 .Nm
 code also provides two extra
Index: share/man/man9/sx.9
===================================================================
--- share/man/man9/sx.9	(wersja 216565)
+++ share/man/man9/sx.9	(kopia robocza)
@@ -26,7 +26,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 28, 2009
+.Dd January 7, 2011
 .Dt SX 9
 .Os
 .Sh NAME
@@ -122,7 +122,7 @@
 specifies a set of optional flags to alter the behavior of
 .Fa sx .
 It contains one or more of the following flags:
-.Bl -tag -width SX_NOADAPTIVE
+.Bl -tag -width SX_NOORDERCHECK
 .It Dv SX_NOADAPTIVE
 If the kernel is not compiled with
 .Cd "options NO_ADAPTIVE_SX" ,
@@ -144,6 +144,10 @@
 .It Dv SX_QUIET
 Do not log any operations for this lock via
 .Xr ktr 4 .
+.It Dv SX_NOORDERCHECK
+Instruct
+.Xr witness 4
+not to report lock ordering problems for this lock.
 .El
 .Pp
 Shared/exclusive locks are destroyed with
Index: share/man/man9/rwlock.9
===================================================================
--- share/man/man9/rwlock.9	(wersja 216565)
+++ share/man/man9/rwlock.9	(kopia robocza)
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd April 1, 2008
+.Dd January 7, 2011
 .Dt RWLOCK 9
 .Os
 .Sh NAME
@@ -141,7 +141,7 @@
 .Fa opts
 argument.
 It contains one or more of the following flags:
-.Bl -tag -width ".Dv RW_NOPROFILE"
+.Bl -tag -width ".Dv RW_NOORDERCHECK"
 .It Dv RW_DUPOK
 Witness should not log messages about duplicate locks being acquired.
 .It Dv RW_NOPROFILE
@@ -156,6 +156,10 @@
 .It Dv RW_RECURSE
 Allow threads to recursively acquire exclusive locks for
 .Fa rw .
+.It Dv RW_NOORDERCHECK
+Instruct
+.Xr witness 4
+not to report lock ordering problems for this lock.
 .El
 .It Fn rw_rlock "struct rwlock *rw"
 Lock
Index: share/man/man9/lock.9
===================================================================
--- share/man/man9/lock.9	(wersja 216565)
+++ share/man/man9/lock.9	(kopia robocza)
@@ -26,7 +26,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 16, 2009
+.Dd January 7, 2011
 .Dt LOCK 9
 .Os
 .Sh NAME
@@ -95,7 +95,7 @@
 .Xr sleep 9 .
 .It Fa flags
 The flags the lock is to be initialized with:
-.Bl -tag -width ".Dv LK_CANRECURSE"
+.Bl -tag -width ".Dv LK_NOORDERCHECK"
 .It Dv LK_ADAPTIVE
 Enable adaptive spinning for this lock if the kernel is compiled with the
 ADAPTIVE_LOCKMGRS option.
@@ -120,6 +120,10 @@
 Use
 .Fa timo
 during a sleep; otherwise, 0 is used.
+.It Dv LK_NOORDERCHECK
+Instruct
+.Xr witness 4
+not to report lock ordering problems for this lock.
 .El
 .El
 .Pp
Index: share/man/man9/rmlock.9
===================================================================
--- share/man/man9/rmlock.9	(wersja 216565)
+++ share/man/man9/rmlock.9	(kopia robocza)
@@ -26,7 +26,7 @@
 .\" $FreeBSD$
 .\"
 .\" Based on rwlock.9 man page
-.Dd November 10, 2007
+.Dd January 7, 2011
 .Dt RMLOCK 9
 .Os
 .Sh NAME
@@ -132,7 +132,7 @@
 .Fa opts
 argument.
 It contains one or more of the following flags:
-.Bl -tag -width ".Dv RM_NOWITNESS"
+.Bl -tag -width ".Dv RM_NOORDERCHECK"
 .It Dv RM_NOWITNESS
 Instruct
 .Xr witness 4
@@ -147,6 +147,10 @@
 .Fn rm_try_rlock
 instead of
 .Fn rm_rlock .
+.It Dv RM_NOORDERCHECK
+Instruct
+.Xr witness 4
+not to report lock ordering problems for this lock.
 .El
 .It Fn rm_rlock "struct rmlock *rm" "struct rm_priotracker* tracker"
 Lock
Index: share/man/man9/mutex.9
===================================================================
--- share/man/man9/mutex.9	(wersja 216565)
+++ share/man/man9/mutex.9	(kopia robocza)
@@ -28,7 +28,7 @@
 .\"	from BSDI $Id: mutex.4,v 1.1.2.3 1998/04/27 22:53:13 ewv Exp $
 .\" $FreeBSD$
 .\"
-.Dd December 21, 2006
+.Dd January 7, 2011
 .Dt MUTEX 9
 .Os
 .Sh NAME
@@ -423,7 +423,7 @@
 .Dv MTX_SPIN
 options is required and only one of those two options may be specified.
 The possibilities are:
-.Bl -tag -width MTX_NOWITNESS
+.Bl -tag -width MTX_NOORDERCHECK
 .It Dv MTX_DEF
 Default mutexes
 will always allow the current thread to be suspended
@@ -448,6 +448,10 @@
 Witness should not log messages about duplicate locks being acquired.
 .It Dv MTX_NOPROFILE
 Do not profile this lock.
+.It Dv MTX_NOORDERCHECK
+Instruct
+.Xr witness 4
+not to report lock ordering problems for this lock.
 .El
 .Ss Lock and Unlock Flags
 The flags passed to the