kernel - Refactor the lwkt_token code, making it faster
[dragonfly.git] / sys / sys / thread.h
CommitLineData
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1/*
2 * SYS/THREAD.H
3 *
4 * Implements the architecture independant portion of the LWKT
5 * subsystem.
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6 *
7 * Types which must already be defined when this header is included by
8 * userland: struct md_thread
2df9fa87 9 *
cbb1e737 10 * $DragonFly: src/sys/sys/thread.h,v 1.97 2008/09/20 04:31:02 sephe Exp $
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11 */
12
13#ifndef _SYS_THREAD_H_
14#define _SYS_THREAD_H_
15
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16#ifndef _SYS_STDINT_H_
17#include <sys/stdint.h> /* __int types */
18#endif
19#ifndef _SYS_PARAM_H_
20#include <sys/param.h> /* MAXCOMLEN */
21#endif
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22#ifndef _SYS_QUEUE_H_
23#include <sys/queue.h> /* TAILQ_* macros */
24#endif
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25#ifndef _SYS_MSGPORT_H_
26#include <sys/msgport.h> /* lwkt_port */
27#endif
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28#ifndef _SYS_TIME_H_
29#include <sys/time.h> /* struct timeval */
30#endif
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31#ifndef _SYS_SPINLOCK_H_
32#include <sys/spinlock.h>
33#endif
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34#ifndef _SYS_IOSCHED_H_
35#include <sys/iosched.h>
36#endif
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37#ifndef _MACHINE_THREAD_H_
38#include <machine/thread.h>
39#endif
8a8d5d85 40
f1d1c3fa 41struct globaldata;
ef09c3ed 42struct lwp;
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43struct proc;
44struct thread;
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45struct lwkt_queue;
46struct lwkt_token;
41a01a4d 47struct lwkt_tokref;
96728c05 48struct lwkt_ipiq;
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49struct lwkt_cpu_msg;
50struct lwkt_cpu_port;
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51struct lwkt_msg;
52struct lwkt_port;
3b6b7bd1 53struct lwkt_cpusync;
4fd10eb6 54union sysunion;
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55
56typedef struct lwkt_queue *lwkt_queue_t;
57typedef struct lwkt_token *lwkt_token_t;
41a01a4d 58typedef struct lwkt_tokref *lwkt_tokref_t;
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59typedef struct lwkt_cpu_msg *lwkt_cpu_msg_t;
60typedef struct lwkt_cpu_port *lwkt_cpu_port_t;
96728c05 61typedef struct lwkt_ipiq *lwkt_ipiq_t;
3b6b7bd1 62typedef struct lwkt_cpusync *lwkt_cpusync_t;
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63typedef struct thread *thread_t;
64
65typedef TAILQ_HEAD(lwkt_queue, thread) lwkt_queue;
f1d1c3fa 66
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67/*
68 * Differentiation between kernel threads and user threads. Userland
69 * programs which want to access to kernel structures have to define
70 * _KERNEL_STRUCTURES. This is a kinda safety valve to prevent badly
71 * written user programs from getting an LWKT thread that is neither the
72 * kernel nor the user version.
73 */
74#if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
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75#ifndef _MACHINE_THREAD_H_
76#include <machine/thread.h> /* md_thread */
77#endif
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78#ifndef _MACHINE_FRAME_H_
79#include <machine/frame.h>
80#endif
81#else
82struct intrframe;
ece04fd0 83#endif
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84
85/*
41a01a4d 86 * Tokens are used to serialize access to information. They are 'soft'
dd55d707 87 * serialization entities that only stay in effect while a thread is
41a01a4d 88 * running. If the thread blocks, other threads can run holding the same
dd55d707 89 * token(s). The tokens are reacquired when the original thread resumes.
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90 *
91 * A thread can depend on its serialization remaining intact through a
92 * preemption. An interrupt which attempts to use the same token as the
93 * thread being preempted will reschedule itself for non-preemptive
94 * operation, so the new token code is capable of interlocking against
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95 * interrupts as well as other cpus. This means that your token can only
96 * be (temporarily) lost if you *explicitly* block.
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97 *
98 * Tokens are managed through a helper reference structure, lwkt_tokref,
99 * which is typically declared on the caller's stack. Multiple tokref's
100 * may reference the same token.
f1d1c3fa 101 */
dd55d707 102
f1d1c3fa 103typedef struct lwkt_token {
c6fbe95a 104 struct lwkt_tokref *t_ref; /* Owning ref or NULL */
7eb611ef 105} lwkt_token;
dd55d707 106
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107#define LWKT_TOKEN_INITIALIZER(head) \
108{ \
109 .t_ref = NULL \
0ca9b5e1 110}
0ca9b5e1 111
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112#define ASSERT_LWKT_TOKEN_HELD(tok) \
113 KKASSERT((tok)->t_ref->tr_owner == curthread)
8ed305a4 114
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115typedef struct lwkt_tokref {
116 lwkt_token_t tr_tok; /* token in question */
c6fbe95a 117 struct thread *tr_owner; /* me */
41a01a4d 118 lwkt_tokref_t tr_next; /* linked list */
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119} lwkt_tokref;
120
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121#define MAXCPUFIFO 16 /* power of 2 */
122#define MAXCPUFIFO_MASK (MAXCPUFIFO - 1)
41a01a4d 123#define LWKT_MAXTOKENS 16 /* max tokens beneficially held by thread */
96728c05 124
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125/*
126 * Always cast to ipifunc_t when registering an ipi. The actual ipi function
127 * is called with both the data and an interrupt frame, but the ipi function
128 * that is registered might only declare a data argument.
129 */
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130typedef void (*ipifunc1_t)(void *arg);
131typedef void (*ipifunc2_t)(void *arg, int arg2);
132typedef void (*ipifunc3_t)(void *arg, int arg2, struct intrframe *frame);
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133
134typedef struct lwkt_ipiq {
135 int ip_rindex; /* only written by target cpu */
166ec852 136 int ip_xindex; /* written by target, indicates completion */
96728c05 137 int ip_windex; /* only written by source cpu */
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138 ipifunc3_t ip_func[MAXCPUFIFO];
139 void *ip_arg1[MAXCPUFIFO];
140 int ip_arg2[MAXCPUFIFO];
4c9f5a7f 141 u_int ip_npoll; /* synchronization to avoid excess IPIs */
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142} lwkt_ipiq;
143
f1d1c3fa 144/*
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145 * CPU Synchronization structure. See lwkt_cpusync_start() and
146 * lwkt_cpusync_finish() for more information.
147 */
148typedef void (*cpusync_func_t)(lwkt_cpusync_t poll);
149typedef void (*cpusync_func2_t)(void *data);
150
151struct lwkt_cpusync {
152 cpusync_func_t cs_run_func; /* run (tandem w/ acquire) */
153 cpusync_func_t cs_fin1_func; /* fin1 (synchronized) */
154 cpusync_func2_t cs_fin2_func; /* fin2 (tandem w/ release) */
155 void *cs_data;
5c71a36a 156 int cs_maxcount;
3b6b7bd1 157 volatile int cs_count;
5c71a36a 158 cpumask_t cs_mask;
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159};
160
161/*
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162 * The standard message and queue structure used for communications between
163 * cpus. Messages are typically queued via a machine-specific non-linked
164 * FIFO matrix allowing any cpu to send a message to any other cpu without
165 * blocking.
166 */
167typedef struct lwkt_cpu_msg {
168 void (*cm_func)(lwkt_cpu_msg_t msg); /* primary dispatch function */
169 int cm_code; /* request code if applicable */
170 int cm_cpu; /* reply to cpu */
171 thread_t cm_originator; /* originating thread for wakeup */
172} lwkt_cpu_msg;
173
174/*
f1d1c3fa 175 * Thread structure. Note that ownership of a thread structure is special
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176 * cased and there is no 'token'. A thread is always owned by the cpu
177 * represented by td_gd, any manipulation of the thread by some other cpu
178 * must be done through cpu_*msg() functions. e.g. you could request
179 * ownership of a thread that way, or hand a thread off to another cpu.
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180 *
181 * NOTE: td_pri is bumped by TDPRI_CRIT when entering a critical section,
182 * but this does not effect how the thread is scheduled by LWKT.
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183 *
184 * NOTE: td_ucred is synchronized from the p_ucred on user->kernel syscall,
185 * trap, and AST/signal transitions to provide a stable ucred for
186 * (primarily) system calls. This field will be NULL for pure kernel
187 * threads.
f1d1c3fa 188 */
96728c05 189struct md_intr_info;
f6bf3af1 190struct caps_kinfo;
96728c05 191
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192struct thread {
193 TAILQ_ENTRY(thread) td_threadq;
73e4f7b9 194 TAILQ_ENTRY(thread) td_allq;
ae8e83e6 195 TAILQ_ENTRY(thread) td_sleepq;
ece04fd0 196 lwkt_port td_msgport; /* built-in message port for replies */
ef09c3ed 197 struct lwp *td_lwp; /* (optional) associated lwp */
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198 struct proc *td_proc; /* (optional) associated process */
199 struct pcb *td_pcb; /* points to pcb and top of kstack */
26a0694b 200 struct globaldata *td_gd; /* associated with this cpu */
ae8050a4 201 const char *td_wmesg; /* string name for blockage */
0cfcada1 202 void *td_wchan; /* waiting on channel */
4b5f931b 203 int td_pri; /* 0-31, 31=highest priority (note 1) */
b8337f35 204 int td_flags; /* TDF flags */
da5fb9ef 205 int td_wdomain; /* domain for wchan address (typ 0) */
96728c05 206 void (*td_preemptable)(struct thread *td, int critpri);
a2a5ad0d 207 void (*td_release)(struct thread *td);
7e1d4bf4 208 char *td_kstack; /* kernel stack */
f470d0c8 209 int td_kstack_size; /* size of kernel stack */
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210 char *td_sp; /* kernel stack pointer for LWKT restore */
211 void (*td_switch)(struct thread *ntd);
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212 __uint64_t td_uticks; /* Statclock hits in user mode (uS) */
213 __uint64_t td_sticks; /* Statclock hits in system mode (uS) */
214 __uint64_t td_iticks; /* Statclock hits processing intr (uS) */
69d78e99 215 int td_locks; /* lockmgr lock debugging */
d666840a 216 int td_unused01;
73e4f7b9 217 int td_refs; /* hold position in gd_tdallq / hold free */
46a3f46d 218 int td_nest_count; /* prevent splz nesting */
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219#ifdef SMP
220 int td_mpcount; /* MP lock held (count) */
0f7a3396 221 int td_cscount; /* cpu synchronization master */
8a8d5d85 222#else
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223 int td_mpcount_unused; /* filler so size matches */
224 int td_cscount_unused;
8a8d5d85 225#endif
79eae878 226 struct iosched_data td_iosdata; /* Dynamic I/O scheduling data */
41f3429e 227 struct timeval td_start; /* start time for a thread/process */
0cfcada1 228 char td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */
99df837e 229 struct thread *td_preempted; /* we preempted this thread */
d86a23e0 230 struct ucred *td_ucred; /* synchronized from p_ucred */
f6bf3af1 231 struct caps_kinfo *td_caps; /* list of client and server registrations */
41a01a4d 232 lwkt_tokref_t td_toks; /* tokens beneficially held */
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233#ifdef DEBUG_CRIT_SECTIONS
234#define CRIT_DEBUG_ARRAY_SIZE 32
235#define CRIT_DEBUG_ARRAY_MASK (CRIT_DEBUG_ARRAY_SIZE - 1)
236 const char *td_crit_debug_array[CRIT_DEBUG_ARRAY_SIZE];
237 int td_crit_debug_index;
238 int td_in_crit_report;
239#endif
85100692 240 struct md_thread td_mach;
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241};
242
2df9fa87 243/*
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244 * Thread flags. Note that TDF_RUNNING is cleared on the old thread after
245 * we switch to the new one, which is necessary because LWKTs don't need
246 * to hold the BGL. This flag is used by the exit code and the managed
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247 * thread migration code. Note in addition that preemption will cause
248 * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING
249 * must also check TDF_PREEMPT_LOCK.
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250 *
251 * LWKT threads stay on their (per-cpu) run queue while running, not to
252 * be confused with user processes which are removed from the user scheduling
253 * run queue while actually running.
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254 *
255 * td_threadq can represent the thread on one of three queues... the LWKT
256 * run queue, a tsleep queue, or an lwkt blocking queue. The LWKT subsystem
257 * does not allow a thread to be scheduled if it already resides on some
258 * queue.
8ad65e08 259 */
d9eea1a5 260#define TDF_RUNNING 0x0001 /* thread still active */
a2a5ad0d 261#define TDF_RUNQ 0x0002 /* on an LWKT run queue */
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262#define TDF_PREEMPT_LOCK 0x0004 /* I have been preempted */
263#define TDF_PREEMPT_DONE 0x0008 /* acknowledge preemption complete */
a2a5ad0d 264#define TDF_IDLE_NOHLT 0x0010 /* we need to spin */
5d21b981 265#define TDF_MIGRATING 0x0020 /* thread is being migrated */
d9d6cb99 266#define TDF_SINTR 0x0040 /* interruptability hint for 'ps' */
344ad853 267#define TDF_TSLEEPQ 0x0080 /* on a tsleep wait queue */
26a0694b 268
4ecf7cc9 269#define TDF_SYSTHREAD 0x0100 /* allocations may use reserve */
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270#define TDF_ALLOCATED_THREAD 0x0200 /* objcache allocated thread */
271#define TDF_ALLOCATED_STACK 0x0400 /* objcache allocated stack */
99df837e 272#define TDF_VERBOSE 0x0800 /* verbose on exit */
dadab5e9 273#define TDF_DEADLKTREAT 0x1000 /* special lockmgr deadlock treatment */
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274#define TDF_STOPREQ 0x2000 /* suspend_kproc */
275#define TDF_WAKEREQ 0x4000 /* resume_kproc */
276#define TDF_TIMEOUT 0x8000 /* tsleep timeout */
03aa8d99 277#define TDF_INTTHREAD 0x00010000 /* interrupt thread */
ae8e83e6 278#define TDF_TSLEEP_DESCHEDULED 0x00020000 /* tsleep core deschedule */
8ec60c3f 279#define TDF_BLOCKED 0x00040000 /* Thread is blocked */
a7422615 280#define TDF_PANICWARN 0x00080000 /* panic warning in switch */
344ad853 281#define TDF_BLOCKQ 0x00100000 /* on block queue */
c2fba90b 282#define TDF_MPSAFE 0x00200000 /* (thread creation) */
c1102e9f 283#define TDF_EXITING 0x00400000 /* thread exiting */
1b251f0a 284#define TDF_USINGFP 0x00800000 /* thread using fp coproc */
aad81e48 285#define TDF_KERNELFP 0x01000000 /* kernel using fp coproc */
cbb1e737 286#define TDF_NETWORK 0x02000000 /* network proto thread */
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287
288/*
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289 * Thread priorities. Typically only one thread from any given
290 * user process scheduling queue is on the LWKT run queue at a time.
291 * Remember that there is one LWKT run queue per cpu.
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292 *
293 * Critical sections are handled by bumping td_pri above TDPRI_MAX, which
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294 * causes interrupts to be masked as they occur. When this occurs a
295 * rollup flag will be set in mycpu->gd_reqflags.
2df9fa87 296 */
f1d1c3fa 297#define TDPRI_IDLE_THREAD 0 /* the idle thread */
50017724 298#define TDPRI_USER_SCHEDULER 2 /* user scheduler helper */
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299#define TDPRI_USER_IDLE 4 /* user scheduler idle */
300#define TDPRI_USER_NORM 6 /* user scheduler normal */
301#define TDPRI_USER_REAL 8 /* user scheduler real time */
9ae9ee8d 302#define TDPRI_KERN_LPSCHED 9 /* scheduler helper for userland sch */
f1d1c3fa 303#define TDPRI_KERN_USER 10 /* kernel / block in syscall */
26a0694b 304#define TDPRI_KERN_DAEMON 12 /* kernel daemon (pageout, etc) */
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305#define TDPRI_SOFT_NORM 14 /* kernel / normal */
306#define TDPRI_SOFT_TIMER 16 /* kernel / timer */
ae8050a4 307#define TDPRI_EXITING 19 /* exiting thread */
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308#define TDPRI_INT_SUPPORT 20 /* kernel / high priority support */
309#define TDPRI_INT_LOW 27 /* low priority interrupt */
310#define TDPRI_INT_MED 28 /* medium priority interrupt */
311#define TDPRI_INT_HIGH 29 /* high priority interrupt */
312#define TDPRI_MAX 31
313
314#define TDPRI_MASK 31
315#define TDPRI_CRIT 32 /* high bits of td_pri used for crit */
2df9fa87 316
d9d13bd5 317#ifdef _KERNEL
f470d0c8 318#define LWKT_THREAD_STACK (UPAGES * PAGE_SIZE)
d9d13bd5 319#endif
f470d0c8 320
ef0fdad1 321#define CACHE_NTHREADS 6
7e1d4bf4 322
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323#define IN_CRITICAL_SECT(td) ((td)->td_pri >= TDPRI_CRIT)
324
40aaf5fc 325extern void lwkt_init(void);
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326extern struct thread *lwkt_alloc_thread(struct thread *, int, int, int);
327extern void lwkt_init_thread(struct thread *, void *, int, int,
328 struct globaldata *);
329extern void lwkt_set_comm(thread_t, const char *, ...);
330extern void lwkt_wait_free(struct thread *);
331extern void lwkt_free_thread(struct thread *);
332extern void lwkt_gdinit(struct globaldata *);
8ad65e08 333extern void lwkt_switch(void);
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334extern void lwkt_preempt(thread_t, int);
335extern void lwkt_schedule(thread_t);
361d01dd 336extern void lwkt_schedule_noresched(thread_t);
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337extern void lwkt_schedule_self(thread_t);
338extern void lwkt_deschedule(thread_t);
339extern void lwkt_deschedule_self(thread_t);
f1d1c3fa 340extern void lwkt_yield(void);
3824f392 341extern void lwkt_user_yield(void);
41a01a4d 342extern void lwkt_token_wait(void);
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343extern void lwkt_hold(thread_t);
344extern void lwkt_rele(thread_t);
3824f392 345extern void lwkt_passive_release(thread_t);
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346
347extern void lwkt_gettoken(lwkt_tokref_t, lwkt_token_t);
348extern int lwkt_trytoken(lwkt_tokref_t, lwkt_token_t);
349extern void lwkt_gettokref(lwkt_tokref_t);
350extern int lwkt_trytokref(lwkt_tokref_t);
351extern void lwkt_reltoken(lwkt_tokref_t);
352extern int lwkt_getalltokens(thread_t);
353extern void lwkt_relalltokens(thread_t);
41a01a4d 354extern void lwkt_drain_token_requests(void);
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355extern void lwkt_token_init(lwkt_token_t);
356extern void lwkt_token_uninit(lwkt_token_t);
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357
358extern void lwkt_token_pool_init(void);
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359extern lwkt_token_t lwkt_token_pool_lookup(void *);
360extern void lwkt_getpooltoken(lwkt_tokref_t, void *);
41a01a4d 361
b9665ad7 362extern void lwkt_setpri(thread_t, int);
03bd0a5e 363extern void lwkt_setpri_initial(thread_t, int);
b9665ad7 364extern void lwkt_setpri_self(int);
b9eb1c19 365extern int lwkt_check_resched(thread_t);
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366extern void lwkt_setcpu_self(struct globaldata *);
367extern void lwkt_migratecpu(int);
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368
369#ifdef SMP
370
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371extern void lwkt_giveaway(struct thread *);
372extern void lwkt_acquire(struct thread *);
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373extern int lwkt_send_ipiq3(struct globaldata *, ipifunc3_t, void *, int);
374extern int lwkt_send_ipiq3_passive(struct globaldata *, ipifunc3_t,
375 void *, int);
376extern int lwkt_send_ipiq3_nowait(struct globaldata *, ipifunc3_t,
377 void *, int);
378extern int lwkt_send_ipiq3_bycpu(int, ipifunc3_t, void *, int);
379extern int lwkt_send_ipiq3_mask(cpumask_t, ipifunc3_t, void *, int);
380extern void lwkt_wait_ipiq(struct globaldata *, int);
381extern int lwkt_seq_ipiq(struct globaldata *);
96728c05 382extern void lwkt_process_ipiq(void);
88c4d2f6 383#ifdef _KERNEL
b9665ad7 384extern void lwkt_process_ipiq_frame(struct intrframe *);
88c4d2f6 385#endif
b8a98473 386extern void lwkt_smp_stopped(void);
6c92c1f2 387extern void lwkt_synchronize_ipiqs(const char *);
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388
389#endif /* SMP */
390
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391extern void lwkt_cpusync_simple(cpumask_t, cpusync_func_t, void *);
392extern void lwkt_cpusync_fastdata(cpumask_t, cpusync_func2_t, void *);
393extern void lwkt_cpusync_start(cpumask_t, lwkt_cpusync_t);
394extern void lwkt_cpusync_add(cpumask_t, lwkt_cpusync_t);
395extern void lwkt_cpusync_finish(lwkt_cpusync_t);
b8a98473 396
26a0694b 397extern void crit_panic(void);
553ea3c8 398extern struct lwp *lwkt_preempted_proc(void);
4b5f931b 399
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400extern int lwkt_create (void (*func)(void *), void *, struct thread **,
401 struct thread *, int, int, const char *, ...);
b153f746 402extern void lwkt_exit (void) __dead2;
e56e4dea 403extern void lwkt_remove_tdallq (struct thread *);
99df837e 404
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405#endif
406