xref: /dragonfly/sys/sys/thread.h (revision 655933d6)
1 /*
2  * SYS/THREAD.H
3  *
4  *	Implements the architecture independant portion of the LWKT
5  *	subsystem.
6  */
7 
8 #ifndef _SYS_THREAD_H_
9 #define	_SYS_THREAD_H_
10 
11 #ifndef _SYS_PARAM_H_
12 #include <sys/param.h>		/* MAXCOMLEN */
13 #endif
14 #ifndef _SYS_QUEUE_H_
15 #include <sys/queue.h>		/* TAILQ_* macros */
16 #endif
17 #ifndef _SYS_MSGPORT_H_
18 #include <sys/msgport.h>	/* lwkt_port */
19 #endif
20 #ifndef _SYS_TIME_H_
21 #include <sys/time.h>   	/* struct timeval */
22 #endif
23 #ifndef _SYS_LOCK_H
24 #include <sys/lock.h>
25 #endif
26 #ifndef _SYS_SPINLOCK_H_
27 #include <sys/spinlock.h>
28 #endif
29 #ifndef _SYS_IOSCHED_H_
30 #include <sys/iosched.h>
31 #endif
32 #include <machine/thread.h>	/* md_thread */
33 #include <machine/stdint.h>
34 #include <machine/ucontext.h>
35 
36 struct globaldata;
37 struct lwp;
38 struct proc;
39 struct thread;
40 struct lwkt_queue;
41 struct lwkt_token;
42 struct lwkt_tokref;
43 struct lwkt_ipiq;
44 #if 0
45 struct lwkt_cpu_msg;
46 struct lwkt_cpu_port;
47 #endif
48 struct lwkt_cpusync;
49 struct fdnode;
50 union sysunion;
51 
52 typedef struct lwkt_queue	*lwkt_queue_t;
53 typedef struct lwkt_token	*lwkt_token_t;
54 typedef struct lwkt_tokref	*lwkt_tokref_t;
55 #if 0
56 typedef struct lwkt_cpu_msg	*lwkt_cpu_msg_t;
57 typedef struct lwkt_cpu_port	*lwkt_cpu_port_t;
58 #endif
59 typedef struct lwkt_ipiq	*lwkt_ipiq_t;
60 typedef struct lwkt_cpusync	*lwkt_cpusync_t;
61 typedef struct thread 		*thread_t;
62 
63 typedef TAILQ_HEAD(lwkt_queue, thread) lwkt_queue;
64 
65 /*
66  * Differentiation between kernel threads and user threads.  Userland
67  * programs which want to access to kernel structures have to define
68  * _KERNEL_STRUCTURES.  This is a kinda safety valve to prevent badly
69  * written user programs from getting an LWKT thread that is neither the
70  * kernel nor the user version.
71  */
72 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
73 #ifndef _SYS_CPUMASK_H_
74 #include <sys/cpumask.h>	/* cpumask_t */
75 #endif
76 #ifndef _CPU_FRAME_H_
77 #include <machine/frame.h>
78 #endif
79 #else
80 struct intrframe;
81 #endif
82 
83 /*
84  * Tokens are used to serialize access to information.  They are 'soft'
85  * serialization entities that only stay in effect while a thread is
86  * running.  If the thread blocks, other threads can run holding the same
87  * token(s).  The tokens are reacquired when the original thread resumes.
88  *
89  * Tokens guarantee that no deadlock can happen regardless of type or
90  * ordering.  However, obtaining the same token first shared, then
91  * stacking exclusive, is not allowed and will panic.
92  *
93  * A thread can depend on its serialization remaining intact through a
94  * preemption.  An interrupt which attempts to use the same token as the
95  * thread being preempted will reschedule itself for non-preemptive
96  * operation, so the new token code is capable of interlocking against
97  * interrupts as well as other cpus.  This means that your token can only
98  * be (temporarily) lost if you *explicitly* block.
99  *
100  * Tokens are managed through a helper reference structure, lwkt_tokref.  Each
101  * thread has a stack of tokref's to keep track of acquired tokens.  Multiple
102  * tokref's may reference the same token.
103  *
104  * EXCLUSIVE TOKENS
105  *	Acquiring an exclusive token requires acquiring the EXCLUSIVE bit
106  *	with count == 0.  If the exclusive bit cannot be acquired, EXCLREQ
107  *	is set.  Once acquired, EXCLREQ is cleared (but could get set by
108  *	another thread also trying for an exclusive lock at any time).
109  *
110  * SHARED TOKENS
111  *	Acquiring a shared token requires waiting for the EXCLUSIVE bit
112  *	to be cleared and then acquiring a count.  A shared lock request
113  *	can temporarily acquire a count and then back it out if it is
114  *	unable to obtain the EXCLUSIVE bit, allowing fetchadd to be used.
115  *
116  *	A thread attempting to get a single shared token will defer to
117  *	pending exclusive requesters.  However, a thread already holding
118  *	one or more tokens and trying to get an additional shared token
119  *	cannot defer to exclusive requesters because doing so can lead
120  *	to a deadlock.
121  *
122  * Multiple exclusive tokens are handled by treating the additional tokens
123  * as a special case of the shared token, incrementing the count value.  This
124  * reduces the complexity of the token release code.
125  */
126 
127 struct lwkt_token {
128     long		t_count;	/* Shared/exclreq/exclusive access */
129     struct lwkt_tokref	*t_ref;		/* Exclusive ref */
130     long		t_collisions;	/* Collision counter */
131     const char		*t_desc;	/* Descriptive name */
132 };
133 
134 #define TOK_EXCLUSIVE	0x00000001	/* Exclusive lock held */
135 #define TOK_EXCLREQ	0x00000002	/* Exclusive request pending */
136 #define TOK_INCR	4		/* Shared count increment */
137 #define TOK_COUNTMASK	(~(long)(TOK_EXCLUSIVE|TOK_EXCLREQ))
138 
139 /*
140  * Static initialization for a lwkt_token.
141  */
142 #define LWKT_TOKEN_INITIALIZER(name)	\
143 {					\
144 	.t_count = 0,			\
145 	.t_ref = NULL,			\
146 	.t_collisions = 0,		\
147 	.t_desc = #name			\
148 }
149 
150 /*
151  * Assert that a particular token is held
152  */
153 #define LWKT_TOKEN_HELD_ANY(tok)	_lwkt_token_held_any(tok, curthread)
154 #define LWKT_TOKEN_HELD_EXCL(tok)	_lwkt_token_held_excl(tok, curthread)
155 
156 #define ASSERT_LWKT_TOKEN_HELD(tok)		\
157 	KKASSERT(LWKT_TOKEN_HELD_ANY(tok))
158 
159 #define ASSERT_LWKT_TOKEN_HELD_EXCL(tok)	\
160 	KKASSERT(LWKT_TOKEN_HELD_EXCL(tok))
161 
162 #define ASSERT_NO_TOKENS_HELD(td)	\
163 	KKASSERT((td)->td_toks_stop == &td->td_toks_array[0])
164 
165 struct lwkt_tokref {
166     lwkt_token_t	tr_tok;		/* token in question */
167     long		tr_count;	/* TOK_EXCLUSIVE|TOK_EXCLREQ or 0 */
168     struct thread	*tr_owner;	/* me */
169 };
170 
171 #define MAXCPUFIFO      256	/* power of 2 */
172 #define MAXCPUFIFO_MASK	(MAXCPUFIFO - 1)
173 #define LWKT_MAXTOKENS	32	/* max tokens beneficially held by thread */
174 
175 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
176 /*
177  * Always cast to ipifunc_t when registering an ipi.  The actual ipi function
178  * is called with both the data and an interrupt frame, but the ipi function
179  * that is registered might only declare a data argument.
180  */
181 typedef void (*ipifunc1_t)(void *arg);
182 typedef void (*ipifunc2_t)(void *arg, int arg2);
183 typedef void (*ipifunc3_t)(void *arg, int arg2, struct intrframe *frame);
184 
185 struct lwkt_ipiq {
186     int		ip_rindex;      /* only written by target cpu */
187     int		ip_xindex;      /* written by target, indicates completion */
188     int		ip_windex;      /* only written by source cpu */
189     int		ip_drain;	/* drain source limit */
190     struct {
191 	ipifunc3_t	func;
192 	void		*arg1;
193 	int		arg2;
194 	char		filler[32 - sizeof(int) - sizeof(void *) * 2];
195     } ip_info[MAXCPUFIFO];
196 };
197 
198 /*
199  * CPU Synchronization structure.  See lwkt_cpusync_init() and
200  * lwkt_cpusync_interlock() for more information.
201  */
202 typedef void (*cpusync_func_t)(void *arg);
203 
204 struct lwkt_cpusync {
205     cpumask_t	cs_mask;		/* cpus running the sync */
206     cpumask_t	cs_mack;		/* mask acknowledge */
207     cpusync_func_t cs_func;		/* function to execute */
208     void	*cs_data;		/* function data */
209 };
210 #endif /* _KERNEL || _KERNEL_STRUCTURES */
211 
212 /*
213  * The standard message and queue structure used for communications between
214  * cpus.  Messages are typically queued via a machine-specific non-linked
215  * FIFO matrix allowing any cpu to send a message to any other cpu without
216  * blocking.
217  */
218 #if 0
219 typedef struct lwkt_cpu_msg {
220     void	(*cm_func)(lwkt_cpu_msg_t msg);	/* primary dispatch function */
221     int		cm_code;		/* request code if applicable */
222     int		cm_cpu;			/* reply to cpu */
223     thread_t	cm_originator;		/* originating thread for wakeup */
224 } lwkt_cpu_msg;
225 #endif
226 
227 /*
228  * per-thread file descriptor cache
229  */
230 struct fdcache {
231 	int     fd;			/* descriptor being cached */
232 	int     locked;
233 	struct file *fp;		/* cached referenced fp */
234 	int	lru;
235 	int	unused[3];
236 } __cachealign;
237 
238 #define NFDCACHE	4		/* max fd's cached by a thread */
239 
240 /*
241  * Thread structure.  Note that ownership of a thread structure is special
242  * cased and there is no 'token'.  A thread is always owned by the cpu
243  * represented by td_gd, any manipulation of the thread by some other cpu
244  * must be done through cpu_*msg() functions.  e.g. you could request
245  * ownership of a thread that way, or hand a thread off to another cpu.
246  *
247  * NOTE: td_ucred is synchronized from the p_ucred on user->kernel syscall,
248  *	 trap, and AST/signal transitions to provide a stable ucred for
249  *	 (primarily) system calls.  This field will be NULL for pure kernel
250  *	 threads.
251  */
252 struct md_intr_info;
253 
254 struct thread {
255     TAILQ_ENTRY(thread) td_threadq;
256     TAILQ_ENTRY(thread) td_allq;
257     TAILQ_ENTRY(thread) td_sleepq;
258     lwkt_port	td_msgport;	/* built-in message port for replies */
259     struct lwp	*td_lwp;	/* (optional) associated lwp */
260     struct proc	*td_proc;	/* (optional) associated process */
261     struct pcb	*td_pcb;	/* points to pcb and top of kstack */
262     struct globaldata *td_gd;	/* associated with this cpu */
263     const char	*td_wmesg;	/* string name for blockage */
264     const volatile void	*td_wchan;	/* waiting on channel */
265     int		td_pri;		/* 0-31, 31=highest priority (note 1) */
266     int		td_critcount;	/* critical section priority */
267     u_int	td_flags;	/* TDF flags */
268     int		td_wdomain;	/* domain for wchan address (typ 0) */
269     void	(*td_preemptable)(struct thread *td, int critcount);
270     void	(*td_release)(struct thread *td);
271     char	*td_kstack;	/* kernel stack */
272     int		td_kstack_size;	/* size of kernel stack */
273     char	*td_sp;		/* kernel stack pointer for LWKT restore */
274     thread_t	(*td_switch)(struct thread *ntd);
275     __uint64_t	td_uticks;	/* Statclock hits in user mode (uS) */
276     __uint64_t	td_sticks;      /* Statclock hits in system mode (uS) */
277     __uint64_t	td_iticks;	/* Statclock hits processing intr (uS) */
278     int		td_locks;	/* lockmgr lock debugging */
279     struct plimit *td_limit;	/* synchronized from proc->p_limit */
280     int		td_refs;	/* hold position in gd_tdallq / hold free */
281     int		td_nest_count;	/* prevent splz nesting */
282     u_int	td_contended;	/* token contention count */
283     u_int	td_mpflags;	/* flags can be set by foreign cpus */
284     int		td_cscount;	/* cpu synchronization master */
285     int		td_wakefromcpu;	/* who woke me up? */
286     int		td_upri;	/* user priority (sub-priority under td_pri) */
287     int		td_type;	/* thread type, TD_TYPE_ */
288     int		td_tracker;	/* misc use (base value 0), recursion count */
289     int		td_fdcache_lru;
290     int		td_unused03[3];	/* for future fields */
291     struct iosched_data td_iosdata;	/* Dynamic I/O scheduling data */
292     struct timeval td_start;	/* start time for a thread/process */
293     char	td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */
294     struct thread *td_preempted; /* we preempted this thread */
295     struct ucred *td_ucred;	/* synchronized from proc->p_ucred */
296     mcontext_t	*td_kfpuctx;	/* kernel_fpu_begin()/kernel_fpu_end() */
297     lwkt_tokref_t td_toks_have;		/* tokens we own */
298     lwkt_tokref_t td_toks_stop;		/* tokens we want */
299     struct lwkt_tokref td_toks_array[LWKT_MAXTOKENS];
300     int		td_fairq_load;		/* fairq */
301     int		td_fairq_count;		/* fairq */
302     struct globaldata *td_migrate_gd;	/* target gd for thread migration */
303     struct fdcache    td_fdcache[NFDCACHE];
304     void	*td_linux_task;		/* drm/linux support */
305 #ifdef DEBUG_CRIT_SECTIONS
306 #define CRIT_DEBUG_ARRAY_SIZE   32
307 #define CRIT_DEBUG_ARRAY_MASK   (CRIT_DEBUG_ARRAY_SIZE - 1)
308     const char	*td_crit_debug_array[CRIT_DEBUG_ARRAY_SIZE];
309     int		td_crit_debug_index;
310     int		td_in_crit_report;
311 #endif
312     struct md_thread td_mach;
313 #ifdef DEBUG_LOCKS
314 #define SPINLOCK_DEBUG_ARRAY_SIZE	32
315    int 	td_spinlock_stack_id[SPINLOCK_DEBUG_ARRAY_SIZE];
316    struct spinlock *td_spinlock_stack[SPINLOCK_DEBUG_ARRAY_SIZE];
317    void 	*td_spinlock_caller_pc[SPINLOCK_DEBUG_ARRAY_SIZE];
318 
319     /*
320      * Track lockmgr locks held; lk->lk_filename:lk->lk_lineno is the holder
321      */
322 #define LOCKMGR_DEBUG_ARRAY_SIZE	8
323     int		td_lockmgr_stack_id[LOCKMGR_DEBUG_ARRAY_SIZE];
324     struct lock	*td_lockmgr_stack[LOCKMGR_DEBUG_ARRAY_SIZE];
325 #endif
326 };
327 
328 #define td_toks_base		td_toks_array[0]
329 #define td_toks_end		td_toks_array[LWKT_MAXTOKENS]
330 
331 #define TD_TOKS_HELD(td)	((td)->td_toks_stop != &(td)->td_toks_base)
332 #define TD_TOKS_NOT_HELD(td)	((td)->td_toks_stop == &(td)->td_toks_base)
333 
334 /*
335  * Thread flags.  Note that TDF_RUNNING is cleared on the old thread after
336  * we switch to the new one, which is necessary because LWKTs don't need
337  * to hold the BGL.  This flag is used by the exit code and the managed
338  * thread migration code.  Note in addition that preemption will cause
339  * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING
340  * must also check TDF_PREEMPT_LOCK.
341  *
342  * LWKT threads stay on their (per-cpu) run queue while running, not to
343  * be confused with user processes which are removed from the user scheduling
344  * run queue while actually running.
345  *
346  * td_threadq can represent the thread on one of three queues... the LWKT
347  * run queue, a tsleep queue, or an lwkt blocking queue.  The LWKT subsystem
348  * does not allow a thread to be scheduled if it already resides on some
349  * queue.
350  */
351 #define TDF_RUNNING		0x00000001	/* thread still active */
352 #define TDF_RUNQ		0x00000002	/* on an LWKT run queue */
353 #define TDF_PREEMPT_LOCK	0x00000004	/* I have been preempted */
354 #define TDF_PREEMPT_DONE	0x00000008	/* ac preemption complete */
355 #define TDF_NOSTART		0x00000010	/* do not schedule on create */
356 #define TDF_MIGRATING		0x00000020	/* thread is being migrated */
357 #define TDF_SINTR		0x00000040	/* interruptability for 'ps' */
358 #define TDF_TSLEEPQ		0x00000080	/* on a tsleep wait queue */
359 
360 #define TDF_SYSTHREAD		0x00000100	/* reserve memory may be used */
361 #define TDF_ALLOCATED_THREAD	0x00000200	/* objcache allocated thread */
362 #define TDF_ALLOCATED_STACK	0x00000400	/* objcache allocated stack */
363 #define TDF_FPU_HEUR		0x00000800	/* active restore on switch */
364 #define TDF_DEADLKTREAT		0x00001000	/* special lockmgr treatment */
365 #define TDF_MARKER		0x00002000	/* tdallq list scan marker */
366 #define TDF_TIMEOUT_RUNNING	0x00004000	/* tsleep timeout race */
367 #define TDF_TIMEOUT		0x00008000	/* tsleep timeout */
368 #define TDF_INTTHREAD		0x00010000	/* interrupt thread */
369 #define TDF_TSLEEP_DESCHEDULED	0x00020000	/* tsleep core deschedule */
370 #define TDF_BLOCKED		0x00040000	/* Thread is blocked */
371 #define TDF_PANICWARN		0x00080000	/* panic warning in switch */
372 #define TDF_BLOCKQ		0x00100000	/* on block queue */
373 #define TDF_FORCE_SPINPORT	0x00200000
374 #define TDF_EXITING		0x00400000	/* thread exiting */
375 #define TDF_USINGFP		0x00800000	/* thread using fp coproc */
376 #define TDF_KERNELFP		0x01000000	/* kernel using fp coproc */
377 #define TDF_DELAYED_WAKEUP	0x02000000
378 #define TDF_FIXEDCPU		0x04000000	/* running cpu is fixed */
379 #define TDF_USERMODE		0x08000000	/* in or entering user mode */
380 #define TDF_NOFAULT		0x10000000	/* force onfault on fault */
381 #define TDF_CLKTHREAD		0x20000000	/* detect INTTHREAD clock */
382 
383 #define TDF_MP_STOPREQ		0x00000001	/* suspend_kproc */
384 #define TDF_MP_WAKEREQ		0x00000002	/* resume_kproc */
385 #define TDF_MP_EXITWAIT		0x00000004	/* reaper, see lwp_wait() */
386 #define TDF_MP_EXITSIG		0x00000008	/* reaper, see lwp_wait() */
387 #define TDF_MP_BATCH_DEMARC	0x00000010	/* batch mode handling */
388 #define TDF_MP_DIDYIELD		0x00000020	/* effects scheduling */
389 
390 #define TD_TYPE_GENERIC		0		/* generic thread */
391 #define TD_TYPE_CRYPTO		1		/* crypto thread */
392 #define TD_TYPE_NETISR		2		/* netisr thread */
393 
394 /*
395  * Thread priorities.  Typically only one thread from any given
396  * user process scheduling queue is on the LWKT run queue at a time.
397  * Remember that there is one LWKT run queue per cpu.
398  *
399  * Critical sections are handled by bumping td_pri above TDPRI_MAX, which
400  * causes interrupts to be masked as they occur.  When this occurs a
401  * rollup flag will be set in mycpu->gd_reqflags.
402  */
403 #define TDPRI_IDLE_THREAD	0	/* the idle thread */
404 #define TDPRI_IDLE_WORK		1	/* idle work (page zero, etc) */
405 #define TDPRI_USER_SCHEDULER	2	/* user scheduler helper */
406 #define TDPRI_USER_IDLE		4	/* user scheduler idle */
407 #define TDPRI_USER_NORM		6	/* user scheduler normal */
408 #define TDPRI_USER_REAL		8	/* user scheduler real time */
409 #define TDPRI_KERN_LPSCHED	9	/* (comparison point only) */
410 #define TDPRI_KERN_USER		10	/* kernel / block in syscall */
411 #define TDPRI_KERN_DAEMON	12	/* kernel daemon (pageout, etc) */
412 #define TDPRI_SOFT_NORM		14	/* kernel / normal */
413 #define TDPRI_SOFT_TIMER	16	/* kernel / timer */
414 #define TDPRI_UNUSED19		19
415 #define TDPRI_INT_SUPPORT	20	/* kernel / high priority support */
416 #define TDPRI_INT_LOW		27	/* low priority interrupt */
417 #define TDPRI_INT_MED		28	/* medium priority interrupt */
418 #define TDPRI_INT_HIGH		29	/* high priority interrupt */
419 #define TDPRI_MAX		31
420 
421 #define LWKT_THREAD_STACK	(UPAGES * PAGE_SIZE)
422 
423 #define IN_CRITICAL_SECT(td)	((td)->td_critcount)
424 
425 #ifdef _KERNEL
426 
427 extern void (*linux_task_drop_callback)(struct thread *);
428 extern void (*linux_proc_drop_callback)(struct proc *);
429 
430 /*
431  * Global tokens
432  */
433 extern struct lwkt_token mp_token;
434 extern struct lwkt_token pmap_token;
435 extern struct lwkt_token dev_token;
436 extern struct lwkt_token vm_token;
437 extern struct lwkt_token vmspace_token;
438 extern struct lwkt_token kvm_token;
439 extern struct lwkt_token sigio_token;
440 extern struct lwkt_token tty_token;
441 extern struct lwkt_token vnode_token;
442 extern struct lwkt_token revoke_token;
443 extern struct lwkt_token kbd_token;
444 extern struct lwkt_token vga_token;
445 
446 /*
447  * Procedures
448  */
449 struct thread *lwkt_alloc_thread(struct thread *, int, int, int);
450 void lwkt_init_thread(struct thread *, void *, int, int, struct globaldata *);
451 void lwkt_set_interrupt_support_thread(void);
452 void lwkt_set_comm(thread_t, const char *, ...) __printflike(2, 3);
453 void lwkt_free_thread(struct thread *);
454 void lwkt_gdinit(struct globaldata *);
455 void lwkt_switch(void);
456 void lwkt_switch_return(struct thread *);
457 void lwkt_preempt(thread_t, int);
458 void lwkt_schedule(thread_t);
459 void lwkt_schedule_noresched(thread_t);
460 void lwkt_schedule_self(thread_t);
461 void lwkt_deschedule(thread_t);
462 void lwkt_deschedule_self(thread_t);
463 void lwkt_yield(void);
464 void lwkt_yield_quick(void);
465 void lwkt_user_yield(void);
466 void lwkt_hold(thread_t);
467 void lwkt_rele(thread_t);
468 void lwkt_passive_release(thread_t);
469 void lwkt_maybe_splz(thread_t);
470 
471 void lwkt_gettoken(lwkt_token_t);
472 void lwkt_gettoken_shared(lwkt_token_t);
473 int  lwkt_trytoken(lwkt_token_t);
474 void lwkt_reltoken(lwkt_token_t);
475 int  lwkt_cnttoken(lwkt_token_t, thread_t);
476 int  lwkt_getalltokens(thread_t, int);
477 void lwkt_relalltokens(thread_t);
478 void lwkt_token_init(lwkt_token_t, const char *);
479 void lwkt_token_uninit(lwkt_token_t);
480 
481 void lwkt_token_pool_init(void);
482 lwkt_token_t lwkt_token_pool_lookup(void *);
483 lwkt_token_t lwkt_getpooltoken(void *);
484 void lwkt_relpooltoken(void *);
485 
486 void lwkt_token_swap(void);
487 
488 void lwkt_setpri(thread_t, int);
489 void lwkt_setpri_initial(thread_t, int);
490 void lwkt_setpri_self(int);
491 void lwkt_schedulerclock(thread_t td);
492 void lwkt_setcpu_self(struct globaldata *);
493 void lwkt_migratecpu(int);
494 
495 void lwkt_giveaway(struct thread *);
496 void lwkt_acquire(struct thread *);
497 int  lwkt_send_ipiq3(struct globaldata *, ipifunc3_t, void *, int);
498 int  lwkt_send_ipiq3_passive(struct globaldata *, ipifunc3_t, void *, int);
499 int  lwkt_send_ipiq3_bycpu(int, ipifunc3_t, void *, int);
500 int  lwkt_send_ipiq3_mask(cpumask_t, ipifunc3_t, void *, int);
501 void lwkt_wait_ipiq(struct globaldata *, int);
502 void lwkt_process_ipiq(void);
503 void lwkt_process_ipiq_frame(struct intrframe *);
504 void lwkt_smp_stopped(void);
505 void lwkt_synchronize_ipiqs(const char *);
506 
507 /* lwkt_cpusync_init() - inline function in sys/thread2.h */
508 void lwkt_cpusync_simple(cpumask_t, cpusync_func_t, void *);
509 void lwkt_cpusync_interlock(lwkt_cpusync_t);
510 void lwkt_cpusync_deinterlock(lwkt_cpusync_t);
511 void lwkt_cpusync_quick(lwkt_cpusync_t);
512 
513 void crit_panic(void) __dead2;
514 struct lwp *lwkt_preempted_proc(void);
515 
516 int  lwkt_create(void (*)(void *), void *, struct thread **, struct thread *,
517 	int, int, const char *, ...) __printflike(7, 8);
518 void lwkt_exit(void) __dead2;
519 void lwkt_remove_tdallq(struct thread *);
520 
521 #endif /* _KERNEL */
522 
523 #endif /* !_SYS_THREAD_H_ */
524 
525