subr_witness.c File Reference

#include <sys/cdefs.h>
#include "opt_ddb.h"
#include "opt_hwpmc_hooks.h"
#include "opt_stack.h"
#include "opt_witness.h"
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/sbuf.h>
#include <sys/sched.h>
#include <sys/stack.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <machine/stdarg.h>

Include dependency graph for subr_witness.c:

Go to the source code of this file.

Data Structures
struct	lock_instance
struct	lock_list_entry
struct	witness
struct	witness_hash
struct	witness_lock_order_key
struct	witness_lock_order_data
struct	witness_lock_order_hash
struct	witness_blessed
struct	witness_pendhelp
struct	witness_order_list_entry

Macros
#define	KTR_WITNESS   0
#define	LI_RECURSEMASK   0x0000ffff /* Recursion depth of lock instance. */
#define	LI_EXCLUSIVE   0x00010000 /* Exclusive lock instance. */
#define	LI_NORELEASE   0x00020000 /* Lock not allowed to be released. */
#define	LI_SLEEPABLE   0x00040000 /* Lock may be held while sleeping. */
#define	WITNESS_COUNT   1536
#define	WITNESS_HASH_SIZE   251 /* Prime, gives load factor < 2 */
#define	WITNESS_PENDLIST   (512 + (MAXCPU * 4))
#define	WITNESS_LO_DATA_COUNT   2048
#define	WITNESS_LO_HASH_SIZE   1021
#define	LOCK_NCHILDREN   5
#define	LOCK_CHILDCOUNT   2048
#define	MAX_W_NAME   64
#define	FULLGRAPH_SBUF_SIZE   512
#define	WITNESS_UNRELATED   0x00 /* No lock order relation. */
#define	WITNESS_PARENT   0x01 /* Parent, aka direct ancestor. */
#define	WITNESS_ANCESTOR   0x02 /* Direct or indirect ancestor. */
#define	WITNESS_CHILD   0x04 /* Child, aka direct descendant. */
#define	WITNESS_DESCENDANT   0x08 /* Direct or indirect descendant. */
#define	WITNESS_ANCESTOR_MASK   (WITNESS_PARENT | WITNESS_ANCESTOR)
#define	WITNESS_DESCENDANT_MASK   (WITNESS_CHILD | WITNESS_DESCENDANT)
#define	WITNESS_RELATED_MASK    (WITNESS_ANCESTOR_MASK | WITNESS_DESCENDANT_MASK)
#define	WITNESS_REVERSAL
#define	WITNESS_RESERVED1   0x20 /* Unused flag, reserved. */
#define	WITNESS_RESERVED2   0x40 /* Unused flag, reserved. */
#define	WITNESS_LOCK_ORDER_KNOWN   0x80 /* This lock order is known. */
#define	WITNESS_DTOA(x)   (((x) & WITNESS_RELATED_MASK) >> 2)
#define	WITNESS_ATOD(x)   (((x) & WITNESS_RELATED_MASK) << 2)
#define	WITNESS_INDEX_ASSERT(i)    MPASS((i) > 0 && (i) <= w_max_used_index && (i) < witness_count)

Enumerations
enum	witness_channel { WITNESS_CONSOLE , WITNESS_LOG , WITNESS_NONE }

Functions
	__FBSDID ("$FreeBSD$")
static	MALLOC_DEFINE (M_WITNESS, "Witness", "Witness")
	STAILQ_HEAD (witness_list, witness)
static __inline int	witness_lock_type_equal (struct witness *w1, struct witness *w2)
static __inline int	witness_lock_order_key_equal (const struct witness_lock_order_key *a, const struct witness_lock_order_key *b)
static int	_isitmyx (struct witness *w1, struct witness *w2, int rmask, const char *fname)
static void	adopt (struct witness *parent, struct witness *child)
static int	blessed (struct witness *, struct witness *)
static void	depart (struct witness *w)
static struct witness *	enroll (const char *description, struct lock_class *lock_class)
static struct lock_instance *	find_instance (struct lock_list_entry *list, const struct lock_object *lock)
static int	isitmychild (struct witness *parent, struct witness *child)
static int	isitmydescendant (struct witness *parent, struct witness *child)
static void	itismychild (struct witness *parent, struct witness *child)
static int	sysctl_debug_witness_badstacks (SYSCTL_HANDLER_ARGS)
static int	sysctl_debug_witness_watch (SYSCTL_HANDLER_ARGS)
static int	sysctl_debug_witness_fullgraph (SYSCTL_HANDLER_ARGS)
static int	sysctl_debug_witness_channel (SYSCTL_HANDLER_ARGS)
static void	witness_add_fullgraph (struct sbuf *sb, struct witness *parent)
static void	witness_enter_debugger (const char *msg)
static void	witness_debugger (int cond, const char *msg)
static void	witness_free (struct witness *m)
static struct witness *	witness_get (void)
static uint32_t	witness_hash_djb2 (const uint8_t *key, uint32_t size)
static struct witness *	witness_hash_get (const char *key)
static void	witness_hash_put (struct witness *w)
static void	witness_init_hash_tables (void)
static void	witness_increment_graph_generation (void)
static void	witness_lock_list_free (struct lock_list_entry *lle)
static struct lock_list_entry *	witness_lock_list_get (void)
static int	witness_lock_order_add (struct witness *parent, struct witness *child)
static int	witness_lock_order_check (struct witness *parent, struct witness *child)
static struct witness_lock_order_data *	witness_lock_order_get (struct witness *parent, struct witness *child)
static void	witness_list_lock (struct lock_instance *instance, int(*prnt)(const char *fmt,...))
static int	witness_output (const char *fmt,...) __printflike(1
static int static int	witness_output_drain (void *arg __unused, const char *data, int len)
static int	witness_voutput (const char *fmt, va_list ap) __printflike(1
static int static void	witness_setflag (struct lock_object *lock, int flag, int set)
	FEATURE (witness, "kernel has witness(9) support")
static	SYSCTL_NODE (_debug, OID_AUTO, witness, CTLFLAG_RW|CTLFLAG_MPSAFE, NULL, "Witness Locking")
	SYSCTL_PROC (_debug_witness, OID_AUTO, watch, CTLFLAG_RWTUN|CTLTYPE_INT|CTLFLAG_MPSAFE, NULL, 0, sysctl_debug_witness_watch, "I", "witness is watching lock operations")
	SYSCTL_INT (_debug_witness, OID_AUTO, skipspin, CTLFLAG_RDTUN, &witness_skipspin, 0, "")
	SYSCTL_INT (_debug_witness, OID_AUTO, witness_count, CTLFLAG_RDTUN, &witness_count, 0, "")
	SYSCTL_PROC (_debug_witness, OID_AUTO, output_channel, CTLTYPE_STRING|CTLFLAG_RWTUN|CTLFLAG_MPSAFE, NULL, 0, sysctl_debug_witness_channel, "A", "Output channel for warnings")
	SYSCTL_PROC (_debug_witness, OID_AUTO, fullgraph, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, 0, sysctl_debug_witness_fullgraph, "A", "Show locks relation graphs")
	SYSCTL_PROC (_debug_witness, OID_AUTO, badstacks, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, 0, sysctl_debug_witness_badstacks, "A", "Show bad witness stacks")
	SYSCTL_INT (_debug_witness, OID_AUTO, free_cnt, CTLFLAG_RD, &w_free_cnt, 0, "")
	SYSCTL_INT (_debug_witness, OID_AUTO, spin_cnt, CTLFLAG_RD, &w_spin_cnt, 0, "")
	SYSCTL_INT (_debug_witness, OID_AUTO, sleep_cnt, CTLFLAG_RD, &w_sleep_cnt, 0, "")
static const char *	fixup_filename (const char *file)
int	witness_startup_count (void)
void	witness_startup (void *mem)
void	witness_init (struct lock_object *lock, const char *type)
void	witness_destroy (struct lock_object *lock)
int	witness_defineorder (struct lock_object *lock1, struct lock_object *lock2)
void	witness_checkorder (struct lock_object *lock, int flags, const char *file, int line, struct lock_object *interlock)
void	witness_lock (struct lock_object *lock, int flags, const char *file, int line)
void	witness_upgrade (struct lock_object *lock, int flags, const char *file, int line)
void	witness_downgrade (struct lock_object *lock, int flags, const char *file, int line)
void	witness_unlock (struct lock_object *lock, int flags, const char *file, int line)
void	witness_thread_exit (struct thread *td)
int	witness_warn (int flags, struct lock_object *lock, const char *fmt,...)
const char *	witness_file (struct lock_object *lock)
int	witness_line (struct lock_object *lock)
int	witness_list_locks (struct lock_list_entry **lock_list, int(*prnt)(const char *fmt,...))
void	witness_display_spinlock (struct lock_object *lock, struct thread *owner, int(*prnt)(const char *fmt,...))
void	witness_save (struct lock_object *lock, const char **filep, int *linep)
void	witness_restore (struct lock_object *lock, const char *file, int line)
void	witness_assert (const struct lock_object *lock, int flags, const char *file, int line)
void	witness_norelease (struct lock_object *lock)
void	witness_releaseok (struct lock_object *lock)
static void	sbuf_print_witness_badstacks (struct sbuf *sb, size_t *oldidx)

Variables
static int	witness_watch = 1
int	witness_skipspin = 0
int	badstack_sbuf_size
int	witness_count = WITNESS_COUNT
static enum witness_channel	witness_channel = WITNESS_CONSOLE
static struct mtx	w_mtx
static struct witness_list	w_free = STAILQ_HEAD_INITIALIZER(w_free)
static struct witness_list	w_all = STAILQ_HEAD_INITIALIZER(w_all)
static struct witness_list	w_spin = STAILQ_HEAD_INITIALIZER(w_spin)
static struct witness_list	w_sleep = STAILQ_HEAD_INITIALIZER(w_sleep)
static struct lock_list_entry *	w_lock_list_free = NULL
static struct witness_pendhelp	pending_locks [WITNESS_PENDLIST]
static u_int	pending_cnt
static int	w_free_cnt
static int	w_spin_cnt
static int	w_sleep_cnt
static struct witness *	w_data
static uint8_t **	w_rmatrix
static struct lock_list_entry	w_locklistdata [LOCK_CHILDCOUNT]
static struct witness_hash	w_hash
static struct witness_lock_order_data	w_lodata [WITNESS_LO_DATA_COUNT]
static struct witness_lock_order_data *	w_lofree = NULL
static struct witness_lock_order_hash	w_lohash
static int	w_max_used_index = 0
static unsigned int	w_generation = 0
static const char	w_notrunning [] = "Witness not running\n"
static const char	w_stillcold [] = "Witness is still cold\n"
static struct witness_order_list_entry	order_lists []
static struct witness_blessed	blessed_list []
static int	witness_cold = 1
static int	witness_spin_warn = 0

Macro Definition Documentation

FULLGRAPH_SBUF_SIZE

#define FULLGRAPH_SBUF_SIZE   512

Definition at line 158 of file subr_witness.c.

KTR_WITNESS

#define KTR_WITNESS   0

Definition at line 128 of file subr_witness.c.

LI_EXCLUSIVE

#define LI_EXCLUSIVE   0x00010000 /* Exclusive lock instance. */

Definition at line 132 of file subr_witness.c.

LI_NORELEASE

#define LI_NORELEASE   0x00020000 /* Lock not allowed to be released. */

Definition at line 133 of file subr_witness.c.

LI_RECURSEMASK

#define LI_RECURSEMASK   0x0000ffff /* Recursion depth of lock instance. */

Definition at line 131 of file subr_witness.c.

LI_SLEEPABLE

#define LI_SLEEPABLE   0x00040000 /* Lock may be held while sleeping. */

Definition at line 134 of file subr_witness.c.

LOCK_CHILDCOUNT

#define LOCK_CHILDCOUNT   2048

Definition at line 154 of file subr_witness.c.

LOCK_NCHILDREN

#define LOCK_NCHILDREN   5

Definition at line 153 of file subr_witness.c.

MAX_W_NAME

#define MAX_W_NAME   64

Definition at line 156 of file subr_witness.c.

WITNESS_ANCESTOR

#define WITNESS_ANCESTOR   0x02 /* Direct or indirect ancestor. */

Definition at line 166 of file subr_witness.c.

WITNESS_ANCESTOR_MASK

#define WITNESS_ANCESTOR_MASK   (WITNESS_PARENT | WITNESS_ANCESTOR)

Definition at line 169 of file subr_witness.c.

WITNESS_ATOD

#define WITNESS_ATOD

(

x

)

(((x) & WITNESS_RELATED_MASK) << 2)

Definition at line 182 of file subr_witness.c.

WITNESS_CHILD

#define WITNESS_CHILD   0x04 /* Child, aka direct descendant. */

Definition at line 167 of file subr_witness.c.

WITNESS_COUNT

#define WITNESS_COUNT   1536

Definition at line 137 of file subr_witness.c.

WITNESS_DESCENDANT

#define WITNESS_DESCENDANT   0x08 /* Direct or indirect descendant. */

Definition at line 168 of file subr_witness.c.

WITNESS_DESCENDANT_MASK

#define WITNESS_DESCENDANT_MASK   (WITNESS_CHILD | WITNESS_DESCENDANT)

Definition at line 170 of file subr_witness.c.

WITNESS_DTOA

#define WITNESS_DTOA

(

x

)

(((x) & WITNESS_RELATED_MASK) >> 2)

Definition at line 179 of file subr_witness.c.

WITNESS_HASH_SIZE

#define WITNESS_HASH_SIZE   251 /* Prime, gives load factor < 2 */

Definition at line 139 of file subr_witness.c.

WITNESS_INDEX_ASSERT

#define WITNESS_INDEX_ASSERT

(

i

)

MPASS((i) > 0 && (i) <= w_max_used_index && (i) < witness_count)

Definition at line 184 of file subr_witness.c.

WITNESS_LO_DATA_COUNT

#define WITNESS_LO_DATA_COUNT   2048

Definition at line 143 of file subr_witness.c.

WITNESS_LO_HASH_SIZE

#define WITNESS_LO_HASH_SIZE   1021

Definition at line 146 of file subr_witness.c.

WITNESS_LOCK_ORDER_KNOWN

#define WITNESS_LOCK_ORDER_KNOWN   0x80 /* This lock order is known. */

Definition at line 176 of file subr_witness.c.

WITNESS_PARENT

#define WITNESS_PARENT   0x01 /* Parent, aka direct ancestor. */

Definition at line 165 of file subr_witness.c.

WITNESS_PENDLIST

#define WITNESS_PENDLIST   (512 + (MAXCPU * 4))

Definition at line 140 of file subr_witness.c.

WITNESS_RELATED_MASK

#define WITNESS_RELATED_MASK    (WITNESS_ANCESTOR_MASK | WITNESS_DESCENDANT_MASK)

Definition at line 171 of file subr_witness.c.

WITNESS_RESERVED1

#define WITNESS_RESERVED1   0x20 /* Unused flag, reserved. */

Definition at line 174 of file subr_witness.c.

WITNESS_RESERVED2

#define WITNESS_RESERVED2   0x40 /* Unused flag, reserved. */

Definition at line 175 of file subr_witness.c.

WITNESS_REVERSAL

#define WITNESS_REVERSAL

Value:

                                          0x10    /* A lock order reversal has been
                                          * observed. */

Definition at line 173 of file subr_witness.c.

WITNESS_UNRELATED

#define WITNESS_UNRELATED   0x00 /* No lock order relation. */

Definition at line 164 of file subr_witness.c.

Enumeration Type Documentation

witness_channel

enum witness_channel

Enumerator
WITNESS_CONSOLE
WITNESS_LOG
WITNESS_NONE

Definition at line 426 of file subr_witness.c.

Function Documentation

__FBSDID()

__FBSDID

(

"$FreeBSD$"

)

_isitmyx()

static int _isitmyx ( struct witness *  w1, struct witness *  w2, int  rmask, const char *  fname  )

static

Definition at line 2087 of file subr_witness.c.

References kdb_backtrace(), printf(), witness::w_index, w_mtx, witness::w_name, w_rmatrix, WITNESS_ATOD, WITNESS_DTOA, WITNESS_INDEX_ASSERT, WITNESS_RELATED_MASK, and witness_watch.

Referenced by isitmychild(), and isitmydescendant().

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adopt()

static void adopt ( struct witness *  parent, struct witness *  child  )

static

Definition at line 1963 of file subr_witness.c.

References child, isitmychild(), kdb_backtrace(), parent, printf(), w_data, w_max_used_index, w_mtx, w_rmatrix, WITNESS_ANCESTOR, WITNESS_ANCESTOR_MASK, WITNESS_CHILD, witness_cold, WITNESS_DESCENDANT, WITNESS_DESCENDANT_MASK, witness_increment_graph_generation(), WITNESS_INDEX_ASSERT, WITNESS_PARENT, and witness_watch.

Referenced by itismychild().

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blessed()

static int blessed ( struct witness *  w1, struct witness *  w2  )

static

Definition at line 2139 of file subr_witness.c.

References witness_blessed::b_lock1, witness_blessed::b_lock2, blessed_list, and witness::w_name.

Referenced by sbuf_print_witness_badstacks(), and witness_checkorder().

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depart()

static void depart ( struct witness *  w )

static

Definition at line 1945 of file subr_witness.c.

References witness::w_class, w_sleep_cnt, w_spin_cnt, and witness_increment_graph_generation().

Referenced by witness_destroy().

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enroll()

static struct witness * enroll ( const char *  description, struct lock_class *  lock_class  )

static

Definition at line 1890 of file subr_witness.c.

References MAX_W_NAME, w_all, witness::w_class, w_mtx, witness::w_name, w_sleep, w_sleep_cnt, w_spin, w_spin_cnt, witness_get(), witness_hash_get(), witness_hash_put(), witness_increment_graph_generation(), witness_skipspin, and witness_watch.

Referenced by witness_init(), and witness_startup().

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FEATURE()

FEATURE	(	witness	,
		"kernel has witness(9) support"
	)

find_instance()

static struct lock_instance * find_instance ( struct lock_list_entry *  list, const struct lock_object *  lock  )

static

Definition at line 2230 of file subr_witness.c.

References lock_instance::li_lock, lock_list_entry::ll_children, lock_list_entry::ll_count, and lock_list_entry::ll_next.

Referenced by witness_assert(), witness_checkorder(), witness_display_spinlock(), witness_downgrade(), witness_lock(), witness_restore(), witness_save(), witness_setflag(), and witness_upgrade().

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fixup_filename()

static const char * fixup_filename ( const char *  file )

static

Definition at line 757 of file subr_witness.c.

Referenced by witness_assert(), witness_checkorder(), witness_downgrade(), witness_list_lock(), witness_unlock(), and witness_upgrade().

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isitmychild()

static int isitmychild ( struct witness *  parent, struct witness *  child  )

static

Definition at line 2121 of file subr_witness.c.

References _isitmyx(), child, parent, and WITNESS_PARENT.

Referenced by adopt(), witness_checkorder(), and witness_lock_order_check().

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isitmydescendant()

static int isitmydescendant ( struct witness *  parent, struct witness *  child  )

static

Definition at line 2131 of file subr_witness.c.

References _isitmyx(), and WITNESS_ANCESTOR_MASK.

Referenced by witness_checkorder(), and witness_defineorder().

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itismychild()

static void itismychild ( struct witness *  parent, struct witness *  child  )

static

Definition at line 2056 of file subr_witness.c.

References adopt(), child, parent, w_mtx, witness_cold, and witness_lock_type_equal().

Referenced by witness_checkorder(), witness_defineorder(), and witness_startup().

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MALLOC_DEFINE()

static MALLOC_DEFINE ( M_WITNESS  , "Witness"  , "Witness"    )

static

sbuf_print_witness_badstacks()

static void sbuf_print_witness_badstacks ( struct sbuf *  sb, size_t *  oldidx  )

static

Definition at line 2616 of file subr_witness.c.

References blessed(), free(), malloc(), sbuf_clear(), sbuf_printf(), stack_copy(), stack_sbuf_print(), stack_zero(), witness::w_class, w_data, w_generation, w_lohash, w_max_used_index, w_mtx, witness::w_name, w_rmatrix, witness_lock_order_get(), WITNESS_REVERSAL, witness_lock_order_data::wlod_stack, and witness_lock_order_hash::wloh_count.

Referenced by sysctl_debug_witness_badstacks().

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STAILQ_HEAD()

STAILQ_HEAD	(	witness_list	,
		witness
	)

sysctl_debug_witness_badstacks()

static int sysctl_debug_witness_badstacks ( SYSCTL_HANDLER_ARGS  )

static

Definition at line 2749 of file subr_witness.c.

References badstack_sbuf_size, sbuf_data(), sbuf_delete(), sbuf_finish(), sbuf_len(), sbuf_new(), sbuf_print_witness_badstacks(), w_notrunning, w_stillcold, witness_cold, and witness_watch.

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sysctl_debug_witness_channel()

static int sysctl_debug_witness_channel ( SYSCTL_HANDLER_ARGS  )

static

Definition at line 2798 of file subr_witness.c.

References buf, name, snprintf(), sysctl_handle_string(), WITNESS_CONSOLE, WITNESS_LOG, and WITNESS_NONE.

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sysctl_debug_witness_fullgraph()

static int sysctl_debug_witness_fullgraph ( SYSCTL_HANDLER_ARGS  )

static

Definition at line 2834 of file subr_witness.c.

References FULLGRAPH_SBUF_SIZE, sbuf_delete(), sbuf_finish(), sbuf_new_for_sysctl(), sbuf_printf(), sysctl_wire_old_buffer(), w_all, w_mtx, w_notrunning, w_stillcold, witness_add_fullgraph(), witness_cold, and witness_watch.

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sysctl_debug_witness_watch()

static int sysctl_debug_witness_watch ( SYSCTL_HANDLER_ARGS  )

static

Definition at line 2880 of file subr_witness.c.

References sysctl_handle_int(), value, and witness_watch.

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SYSCTL_INT() [1/5]

SYSCTL_INT	(	_debug_witness	,
		OID_AUTO	,
		free_cnt	,
		CTLFLAG_RD	,
		&	w_free_cnt,
		0	,
		""
	)

SYSCTL_INT() [2/5]

SYSCTL_INT	(	_debug_witness	,
		OID_AUTO	,
		skipspin	,
		CTLFLAG_RDTUN	,
		&	witness_skipspin,
		0	,
		""
	)

SYSCTL_INT() [3/5]

SYSCTL_INT	(	_debug_witness	,
		OID_AUTO	,
		sleep_cnt	,
		CTLFLAG_RD	,
		&	w_sleep_cnt,
		0	,
		""
	)

SYSCTL_INT() [4/5]

SYSCTL_INT	(	_debug_witness	,
		OID_AUTO	,
		spin_cnt	,
		CTLFLAG_RD	,
		&	w_spin_cnt,
		0	,
		""
	)

SYSCTL_INT() [5/5]

SYSCTL_INT	(	_debug_witness	,
		OID_AUTO	,
		witness_count	,
		CTLFLAG_RDTUN	,
		&	witness_count,
		0	,
		""
	)

SYSCTL_NODE()

static SYSCTL_NODE ( _debug  , OID_AUTO  , witness  , CTLFLAG_RW|  CTLFLAG_MPSAFE, NULL  , "Witness Locking"    )

static

SYSCTL_PROC() [1/4]

SYSCTL_PROC	(	_debug_witness	,
		OID_AUTO	,
		badstacks	,
		CTLTYPE_STRING|CTLFLAG_RD|	CTLFLAG_MPSAFE,
		NULL	,
		0	,
		sysctl_debug_witness_badstacks	,
		"A"	,
		"Show bad witness stacks"
	)

SYSCTL_PROC() [2/4]

SYSCTL_PROC	(	_debug_witness	,
		OID_AUTO	,
		fullgraph	,
		CTLTYPE_STRING|CTLFLAG_RD|	CTLFLAG_MPSAFE,
		NULL	,
		0	,
		sysctl_debug_witness_fullgraph	,
		"A"	,
		"Show locks relation graphs"
	)

SYSCTL_PROC() [3/4]

SYSCTL_PROC	(	_debug_witness	,
		OID_AUTO	,
		output_channel	,
		CTLTYPE_STRING|CTLFLAG_RWTUN|	CTLFLAG_MPSAFE,
		NULL	,
		0	,
		sysctl_debug_witness_channel	,
		"A"	,
		"Output channel for warnings"
	)

SYSCTL_PROC() [4/4]

SYSCTL_PROC	(	_debug_witness	,
		OID_AUTO	,
		watch	,
		CTLFLAG_RWTUN|CTLTYPE_INT|	CTLFLAG_MPSAFE,
		NULL	,
		0	,
		sysctl_debug_witness_watch	,
		"I"	,
		"witness is watching lock operations"
	)

witness_add_fullgraph()

static void witness_add_fullgraph ( struct sbuf *  sb, struct witness *  parent  )

static

Definition at line 2896 of file subr_witness.c.

References sbuf_printf(), w_data, witness::w_index, w_max_used_index, witness::w_name, w_rmatrix, witness_add_fullgraph(), WITNESS_INDEX_ASSERT, and WITNESS_PARENT.

Referenced by sysctl_debug_witness_fullgraph(), and witness_add_fullgraph().

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witness_assert()

void witness_assert	(	const struct lock_object *	lock,
		int	flags,
		const char *	file,
		int	line
	)

Definition at line 2426 of file subr_witness.c.

References find_instance(), fixup_filename(), flags, LI_EXCLUSIVE, lock_instance::li_flags, LI_RECURSEMASK, and witness_watch.

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witness_checkorder()

void witness_checkorder	(	struct lock_object *	lock,
		int	flags,
		const char *	file,
		int	line,
		struct lock_object *	interlock
	)

Definition at line 1109 of file subr_witness.c.

References blessed(), buf, data, find_instance(), fixup_filename(), flags, Giant, isitmychild(), isitmydescendant(), itismychild(), kdb_active, KTR_WITNESS, LI_EXCLUSIVE, lock_instance::li_file, lock_instance::li_flags, lock_instance::li_line, lock_instance::li_lock, LI_RECURSEMASK, LI_SLEEPABLE, lock_list_entry::ll_children, lock_list_entry::ll_count, lock_list_entry::ll_next, LOCK_CHILDCOUNT, LOCK_NCHILDREN, sbuf_delete(), sbuf_finish(), sbuf_new(), sbuf_printf(), sbuf_set_drain(), stack_copy(), stack_sbuf_print_flags(), witness::w_class, witness::w_index, w_mtx, witness::w_name, w_rmatrix, witness_cold, witness_debugger(), witness_enter_debugger(), witness_increment_graph_generation(), witness_lock_order_add(), witness_lock_order_check(), witness_lock_order_get(), witness_output(), witness_output_drain(), and WITNESS_REVERSAL.

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witness_debugger()

static void witness_debugger ( int  cond, const char *  msg  )

static

Definition at line 3107 of file subr_witness.c.

References buf, sbuf_finish(), sbuf_new(), sbuf_set_drain(), st, stack_zero(), witness_enter_debugger(), witness_output(), and witness_output_drain().

Referenced by witness_checkorder(), and witness_warn().

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witness_defineorder()

int witness_defineorder	(	struct lock_object *	lock1,
		struct lock_object *	lock2
	)

Definition at line 1076 of file subr_witness.c.

References isitmydescendant(), itismychild(), KTR_WITNESS, w_mtx, and witness_watch.

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witness_destroy()

void witness_destroy

(

struct lock_object *

lock

)

Definition at line 917 of file subr_witness.c.

References depart(), panic(), w_mtx, and witness_cold.

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witness_display_spinlock()

void witness_display_spinlock	(	struct lock_object *	lock,
		struct thread *	owner,
		int(*)(const char *fmt,...)	prnt
	)

Definition at line 2339 of file subr_witness.c.

References find_instance(), pcpu_find(), and witness_list_lock().

Referenced by _mtx_lock_indefinite_check().

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witness_downgrade()

void witness_downgrade	(	struct lock_object *	lock,
		int	flags,
		const char *	file,
		int	line
	)

Definition at line 1608 of file subr_witness.c.

References find_instance(), fixup_filename(), LI_EXCLUSIVE, lock_instance::li_flags, LI_RECURSEMASK, witness_cold, and witness_watch.

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witness_enter_debugger()

static void witness_enter_debugger ( const char *  msg )

static

Definition at line 3132 of file subr_witness.c.

References kdb_enter().

Referenced by witness_checkorder(), and witness_debugger().

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witness_file()

const char * witness_file

(

struct lock_object *

lock

)

Definition at line 1868 of file subr_witness.c.

References witness_cold.

witness_free()

static void witness_free ( struct witness *  m )

static

Definition at line 2191 of file subr_witness.c.

References w_free, and w_free_cnt.

Referenced by witness_startup().

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witness_get()

static struct witness * witness_get ( void  )

static

Definition at line 2159 of file subr_witness.c.

References printf(), w_free, w_free_cnt, witness::w_index, w_max_used_index, w_mtx, witness_cold, witness_count, and witness_watch.

Referenced by enroll().

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witness_hash_djb2()

static uint32_t witness_hash_djb2 ( const uint8_t *  key, uint32_t  size  )

static

Definition at line 2921 of file subr_witness.c.

Referenced by witness_hash_get(), witness_hash_put(), witness_lock_order_add(), and witness_lock_order_get().

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witness_hash_get()

static struct witness * witness_hash_get ( const char *  key )

static

Definition at line 2969 of file subr_witness.c.

References w_hash, w_mtx, witness::w_name, witness_hash::wh_array, witness_hash::wh_size, witness_cold, and witness_hash_djb2().

Referenced by enroll(), and witness_hash_put().

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witness_hash_put()

static void witness_hash_put ( struct witness *  w )

static

Definition at line 2990 of file subr_witness.c.

References w_hash, w_mtx, witness::w_name, witness_hash::wh_array, witness_hash::wh_count, witness_hash::wh_size, witness_cold, witness_hash_djb2(), and witness_hash_get().

Referenced by enroll().

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witness_increment_graph_generation()

static void witness_increment_graph_generation ( void  )

static

Definition at line 3090 of file subr_witness.c.

References w_generation, w_mtx, and witness_cold.

Referenced by adopt(), depart(), enroll(), and witness_checkorder().

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witness_init()

void witness_init	(	struct lock_object *	lock,
		const char *	type
	)

Definition at line 876 of file subr_witness.c.

References enroll(), panic(), pending_cnt, pending_locks, type, witness_pendhelp::wh_lock, witness_pendhelp::wh_type, witness_cold, WITNESS_PENDLIST, and witness_watch.

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witness_init_hash_tables()

static void witness_init_hash_tables ( void  )

static

Definition at line 2942 of file subr_witness.c.

References w_hash, w_lodata, w_lofree, w_lohash, witness_hash::wh_array, witness_hash::wh_count, witness_hash::wh_size, witness_cold, WITNESS_HASH_SIZE, WITNESS_LO_DATA_COUNT, WITNESS_LO_HASH_SIZE, witness_lock_order_data::wlod_next, witness_lock_order_hash::wloh_array, witness_lock_order_hash::wloh_count, and witness_lock_order_hash::wloh_size.

Referenced by witness_startup().

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witness_line()

int witness_line

(

struct lock_object *

lock

)

Definition at line 1879 of file subr_witness.c.

References witness_cold.

witness_list_lock()

static void witness_list_lock ( struct lock_instance *  instance, int(*)(const char *fmt,...)  prnt  )

static

Definition at line 2246 of file subr_witness.c.

References fixup_filename(), LI_EXCLUSIVE, lock_instance::li_file, lock_instance::li_flags, lock_instance::li_line, lock_instance::li_lock, and LI_RECURSEMASK.

Referenced by witness_display_spinlock(), witness_list_locks(), witness_thread_exit(), and witness_warn().

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witness_list_locks()

int witness_list_locks	(	struct lock_list_entry **	lock_list,
		int(*)(const char *fmt,...)	prnt
	)

Definition at line 2316 of file subr_witness.c.

References lock_list_entry::ll_children, lock_list_entry::ll_count, lock_list_entry::ll_next, and witness_list_lock().

Referenced by witness_warn().

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witness_lock()

void witness_lock	(	struct lock_object *	lock,
		int	flags,
		const char *	file,
		int	line
	)

Definition at line 1503 of file subr_witness.c.

References find_instance(), flags, KTR_WITNESS, LI_EXCLUSIVE, lock_instance::li_file, lock_instance::li_flags, lock_instance::li_line, lock_instance::li_lock, LI_RECURSEMASK, LI_SLEEPABLE, lock_list_entry::ll_children, lock_list_entry::ll_count, lock_list_entry::ll_next, LOCK_NCHILDREN, witness_cold, witness_lock_list_get(), and witness_watch.

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witness_lock_list_free()

static void witness_lock_list_free ( struct lock_list_entry *  lle )

static

Definition at line 2220 of file subr_witness.c.

References lock_list_entry::ll_next, w_lock_list_free, and w_mtx.

Referenced by witness_startup(), witness_thread_exit(), and witness_unlock().

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witness_lock_list_get()

static struct lock_list_entry * witness_lock_list_get ( void  )

static

Definition at line 2199 of file subr_witness.c.

References lock_list_entry::ll_next, printf(), w_lock_list_free, w_mtx, and witness_watch.

Referenced by witness_lock().

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witness_lock_order_add()

static int witness_lock_order_add ( struct witness *  parent, struct witness *  child  )

static

Definition at line 3057 of file subr_witness.c.

References child, data, witness_lock_order_key::from, parent, stack_zero(), witness_lock_order_key::to, w_lofree, w_lohash, w_rmatrix, witness_hash_djb2(), WITNESS_INDEX_ASSERT, WITNESS_LOCK_ORDER_KNOWN, witness_lock_order_hash::wloh_array, witness_lock_order_hash::wloh_count, and witness_lock_order_hash::wloh_size.

Referenced by witness_checkorder().

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witness_lock_order_check()

static int witness_lock_order_check ( struct witness *  parent, struct witness *  child  )

static

Definition at line 3044 of file subr_witness.c.

References child, isitmychild(), parent, w_rmatrix, and WITNESS_LOCK_ORDER_KNOWN.

Referenced by witness_checkorder().

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witness_lock_order_get()

static struct witness_lock_order_data * witness_lock_order_get ( struct witness *  parent, struct witness *  child  )

static

Definition at line 3010 of file subr_witness.c.

References child, data, witness_lock_order_key::from, parent, witness_lock_order_key::to, w_lohash, w_rmatrix, witness_hash_djb2(), WITNESS_INDEX_ASSERT, witness_lock_order_key_equal(), WITNESS_LOCK_ORDER_KNOWN, witness_lock_order_hash::wloh_array, and witness_lock_order_hash::wloh_size.

Referenced by sbuf_print_witness_badstacks(), and witness_checkorder().

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witness_lock_order_key_equal()

static __inline int witness_lock_order_key_equal ( const struct witness_lock_order_key *  a, const struct witness_lock_order_key *  b  )

static

Definition at line 306 of file subr_witness.c.

References witness_lock_order_key::from, and witness_lock_order_key::to.

Referenced by witness_lock_order_get().

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witness_lock_type_equal()

static __inline int witness_lock_type_equal ( struct witness *  w1, struct witness *  w2  )

static

Definition at line 298 of file subr_witness.c.

References witness::w_class.

Referenced by itismychild().

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witness_norelease()

void witness_norelease

(

struct lock_object *

lock

)

Definition at line 2528 of file subr_witness.c.

References LI_NORELEASE, and witness_setflag().

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witness_output()

static int witness_output ( const char *  fmt,   ...  )

static

Definition at line 2262 of file subr_witness.c.

References witness_voutput().

Referenced by witness_checkorder(), witness_debugger(), witness_output_drain(), witness_thread_exit(), and witness_unlock().

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witness_output_drain()

static int witness_output_drain ( void *arg  __unused, const char *  data, int  len  )

static

Definition at line 3099 of file subr_witness.c.

References data, and witness_output().

Referenced by witness_checkorder(), and witness_debugger().

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witness_releaseok()

void witness_releaseok

(

struct lock_object *

lock

)

Definition at line 2535 of file subr_witness.c.

References LI_NORELEASE, and witness_setflag().

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witness_restore()

void witness_restore	(	struct lock_object *	lock,
		const char *	file,
		int	line
	)

Definition at line 2389 of file subr_witness.c.

References find_instance(), lock_instance::li_file, lock_instance::li_line, witness_cold, witness_skipspin, and witness_watch.

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witness_save()

void witness_save	(	struct lock_object *	lock,
		const char **	filep,
		int *	linep
	)

Definition at line 2354 of file subr_witness.c.

References find_instance(), lock_instance::li_file, lock_instance::li_line, witness_cold, witness_skipspin, and witness_watch.

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witness_setflag()

static void witness_setflag ( struct lock_object *  lock, int  flag, int  set  )

static

Definition at line 2498 of file subr_witness.c.

References find_instance(), flag, lock_instance::li_flags, set, witness_skipspin, and witness_watch.

Referenced by witness_norelease(), and witness_releaseok().

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witness_startup()

void witness_startup

(

void *

mem

)

Definition at line 789 of file subr_witness.c.

References badstack_sbuf_size, enroll(), Giant, itismychild(), KTR_WITNESS, LOCK_CHILDCOUNT, order_lists, pending_locks, witness_order_list_entry::w_class, w_data, w_free, w_free_cnt, witness::w_index, w_locklistdata, w_mtx, witness_order_list_entry::w_name, w_rmatrix, witness_pendhelp::wh_lock, witness_cold, witness_count, witness_free(), witness_init_hash_tables(), witness_lock_list_free(), and witness_spin_warn.

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witness_startup_count()

int witness_startup_count

(

void

)

Definition at line 771 of file subr_witness.c.

References w_rmatrix, and witness_count.

witness_thread_exit()

void witness_thread_exit

(

struct thread *

td

)

Definition at line 1763 of file subr_witness.c.

References lock_list_entry::ll_children, lock_list_entry::ll_count, lock_list_entry::ll_next, witness_list_lock(), witness_lock_list_free(), and witness_output().

Referenced by thread_exit().

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witness_unlock()

void witness_unlock	(	struct lock_object *	lock,
		int	flags,
		const char *	file,
		int	line
	)

Definition at line 1654 of file subr_witness.c.

References fixup_filename(), flags, KTR_WITNESS, LI_EXCLUSIVE, lock_instance::li_file, lock_instance::li_flags, lock_instance::li_line, lock_instance::li_lock, LI_NORELEASE, LI_RECURSEMASK, lock_list_entry::ll_next, witness_cold, witness_lock_list_free(), witness_output(), and witness_watch.

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witness_upgrade()

void witness_upgrade	(	struct lock_object *	lock,
		int	flags,
		const char *	file,
		int	line
	)

Definition at line 1563 of file subr_witness.c.

References find_instance(), fixup_filename(), LI_EXCLUSIVE, lock_instance::li_flags, LI_RECURSEMASK, witness_cold, and witness_watch.

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witness_voutput()

static int witness_voutput ( const char *  fmt, va_list  ap  )

static

Definition at line 2274 of file subr_witness.c.

References vlog(), vprintf(), WITNESS_CONSOLE, WITNESS_LOG, and WITNESS_NONE.

Referenced by witness_output().

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witness_warn()

int witness_warn	(	int	flags,
		struct lock_object *	lock,
		const char *	fmt,
			...
	)

Definition at line 1796 of file subr_witness.c.

References flags, Giant, lock_instance::li_flags, lock_instance::li_lock, LI_SLEEPABLE, lock_list_entry::ll_children, lock_list_entry::ll_count, lock_list_entry::ll_next, printf(), vprintf(), witness_cold, witness_debugger(), witness_list_lock(), witness_list_locks(), and witness_watch.

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Variable Documentation

badstack_sbuf_size

int badstack_sbuf_size

Definition at line 417 of file subr_witness.c.

Referenced by sysctl_debug_witness_badstacks(), and witness_startup().

blessed_list

struct witness_blessed blessed_list[]

static

Initial value:

= {
        
        { "dirhash",    "bufwait" },
 
        
        { "ufs",        "bufwait" },
}

Definition at line 729 of file subr_witness.c.

Referenced by blessed().

order_lists

struct witness_order_list_entry order_lists[]

static

Definition at line 492 of file subr_witness.c.

Referenced by witness_startup().

pending_cnt

u_int pending_cnt

static

Definition at line 467 of file subr_witness.c.

Referenced by witness_init().

pending_locks

struct witness_pendhelp pending_locks[WITNESS_PENDLIST]

static

Definition at line 466 of file subr_witness.c.

Referenced by witness_init(), and witness_startup().

w_all

struct witness_list w_all = STAILQ_HEAD_INITIALIZER(w_all)

static

Definition at line 458 of file subr_witness.c.

Referenced by enroll(), and sysctl_debug_witness_fullgraph().

w_data

struct witness* w_data

static

Definition at line 475 of file subr_witness.c.

Referenced by adopt(), sbuf_print_witness_badstacks(), witness_add_fullgraph(), and witness_startup().

w_free

struct witness_list w_free = STAILQ_HEAD_INITIALIZER(w_free)

static

Definition at line 457 of file subr_witness.c.

Referenced by witness_free(), witness_get(), and witness_startup().

w_free_cnt

int w_free_cnt

static

Definition at line 469 of file subr_witness.c.

Referenced by witness_free(), witness_get(), and witness_startup().

w_generation

unsigned int w_generation = 0

static

Definition at line 485 of file subr_witness.c.

Referenced by sbuf_print_witness_badstacks(), and witness_increment_graph_generation().

w_hash

struct witness_hash w_hash

static

Definition at line 478 of file subr_witness.c.

Referenced by witness_hash_get(), witness_hash_put(), and witness_init_hash_tables().

w_lock_list_free

struct lock_list_entry* w_lock_list_free = NULL

static

Definition at line 465 of file subr_witness.c.

Referenced by witness_lock_list_free(), and witness_lock_list_get().

w_locklistdata

struct lock_list_entry w_locklistdata[LOCK_CHILDCOUNT]

static

Definition at line 477 of file subr_witness.c.

Referenced by witness_startup().

w_lodata

struct witness_lock_order_data w_lodata[WITNESS_LO_DATA_COUNT]

static

Definition at line 481 of file subr_witness.c.

Referenced by witness_init_hash_tables().

w_lofree

struct witness_lock_order_data* w_lofree = NULL

static

Definition at line 482 of file subr_witness.c.

Referenced by witness_init_hash_tables(), and witness_lock_order_add().

w_lohash

struct witness_lock_order_hash w_lohash

static

Definition at line 483 of file subr_witness.c.

Referenced by sbuf_print_witness_badstacks(), witness_init_hash_tables(), witness_lock_order_add(), and witness_lock_order_get().

w_max_used_index

int w_max_used_index = 0

static

Definition at line 484 of file subr_witness.c.

Referenced by adopt(), sbuf_print_witness_badstacks(), witness_add_fullgraph(), and witness_get().

w_mtx

struct mtx w_mtx

static

Definition at line 454 of file subr_witness.c.

Referenced by _isitmyx(), adopt(), enroll(), itismychild(), sbuf_print_witness_badstacks(), sysctl_debug_witness_fullgraph(), witness_checkorder(), witness_defineorder(), witness_destroy(), witness_get(), witness_hash_get(), witness_hash_put(), witness_increment_graph_generation(), witness_lock_list_free(), witness_lock_list_get(), and witness_startup().

w_notrunning

const char w_notrunning[] = "Witness not running\n"

static

Definition at line 486 of file subr_witness.c.

Referenced by sysctl_debug_witness_badstacks(), and sysctl_debug_witness_fullgraph().

w_rmatrix

uint8_t** w_rmatrix

static

Definition at line 476 of file subr_witness.c.

Referenced by _isitmyx(), adopt(), sbuf_print_witness_badstacks(), witness_add_fullgraph(), witness_checkorder(), witness_lock_order_add(), witness_lock_order_check(), witness_lock_order_get(), witness_startup(), and witness_startup_count().

w_sleep

struct witness_list w_sleep = STAILQ_HEAD_INITIALIZER(w_sleep)

static

Definition at line 462 of file subr_witness.c.

Referenced by enroll().

w_sleep_cnt

int w_sleep_cnt

static

Definition at line 469 of file subr_witness.c.

Referenced by depart(), and enroll().

w_spin

struct witness_list w_spin = STAILQ_HEAD_INITIALIZER(w_spin)

static

Definition at line 461 of file subr_witness.c.

Referenced by enroll().

w_spin_cnt

int w_spin_cnt

static

Definition at line 469 of file subr_witness.c.

Referenced by depart(), and enroll().

w_stillcold

const char w_stillcold[] = "Witness is still cold\n"

static

Definition at line 487 of file subr_witness.c.

Referenced by sysctl_debug_witness_badstacks(), and sysctl_debug_witness_fullgraph().

witness_channel

enum witness_channel witness_channel = WITNESS_CONSOLE

static

Definition at line 432 of file subr_witness.c.

witness_cold

int witness_cold = 1

static

Definition at line 747 of file subr_witness.c.

Referenced by adopt(), itismychild(), sysctl_debug_witness_badstacks(), sysctl_debug_witness_fullgraph(), witness_checkorder(), witness_destroy(), witness_downgrade(), witness_file(), witness_get(), witness_hash_get(), witness_hash_put(), witness_increment_graph_generation(), witness_init(), witness_init_hash_tables(), witness_line(), witness_lock(), witness_restore(), witness_save(), witness_startup(), witness_unlock(), witness_upgrade(), and witness_warn().

witness_count

int witness_count = WITNESS_COUNT

Definition at line 419 of file subr_witness.c.

Referenced by witness_get(), witness_startup(), and witness_startup_count().

witness_skipspin

int witness_skipspin = 0

Definition at line 413 of file subr_witness.c.

Referenced by enroll(), witness_restore(), witness_save(), and witness_setflag().

witness_spin_warn

int witness_spin_warn = 0

static

Definition at line 753 of file subr_witness.c.

Referenced by witness_startup().

witness_watch

int witness_watch = 1

static

Definition at line 378 of file subr_witness.c.

Referenced by _isitmyx(), adopt(), enroll(), sysctl_debug_witness_badstacks(), sysctl_debug_witness_fullgraph(), sysctl_debug_witness_watch(), witness_assert(), witness_defineorder(), witness_downgrade(), witness_get(), witness_init(), witness_lock(), witness_lock_list_get(), witness_restore(), witness_save(), witness_setflag(), witness_unlock(), witness_upgrade(), and witness_warn().