1 /* 2 * SYS/THREAD.H 3 * 4 * Implements the architecture independant portion of the LWKT 5 * subsystem. 6 * 7 * Types which must already be defined when this header is included by 8 * userland: struct md_thread 9 * 10 * $DragonFly: src/sys/sys/thread.h,v 1.97 2008/09/20 04:31:02 sephe Exp $ 11 */ 12 13 #ifndef _SYS_THREAD_H_ 14 #define _SYS_THREAD_H_ 15 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 22 #ifndef _SYS_QUEUE_H_ 23 #include <sys/queue.h> /* TAILQ_* macros */ 24 #endif 25 #ifndef _SYS_MSGPORT_H_ 26 #include <sys/msgport.h> /* lwkt_port */ 27 #endif 28 #ifndef _SYS_TIME_H_ 29 #include <sys/time.h> /* struct timeval */ 30 #endif 31 #ifndef _SYS_SPINLOCK_H_ 32 #include <sys/spinlock.h> 33 #endif 34 #ifndef _SYS_IOSCHED_H_ 35 #include <sys/iosched.h> 36 #endif 37 #ifndef _MACHINE_THREAD_H_ 38 #include <machine/thread.h> 39 #endif 40 41 struct globaldata; 42 struct lwp; 43 struct proc; 44 struct thread; 45 struct lwkt_queue; 46 struct lwkt_token; 47 struct lwkt_tokref; 48 struct lwkt_ipiq; 49 struct lwkt_cpu_msg; 50 struct lwkt_cpu_port; 51 struct lwkt_msg; 52 struct lwkt_port; 53 struct lwkt_cpusync; 54 union sysunion; 55 56 typedef struct lwkt_queue *lwkt_queue_t; 57 typedef struct lwkt_token *lwkt_token_t; 58 typedef struct lwkt_tokref *lwkt_tokref_t; 59 typedef struct lwkt_cpu_msg *lwkt_cpu_msg_t; 60 typedef struct lwkt_cpu_port *lwkt_cpu_port_t; 61 typedef struct lwkt_ipiq *lwkt_ipiq_t; 62 typedef struct lwkt_cpusync *lwkt_cpusync_t; 63 typedef struct thread *thread_t; 64 65 typedef TAILQ_HEAD(lwkt_queue, thread) lwkt_queue; 66 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) 75 #ifndef _MACHINE_THREAD_H_ 76 #include <machine/thread.h> /* md_thread */ 77 #endif 78 #ifndef _MACHINE_FRAME_H_ 79 #include <machine/frame.h> 80 #endif 81 #else 82 struct intrframe; 83 #endif 84 85 /* 86 * Tokens are used to serialize access to information. They are 'soft' 87 * serialization entities that only stay in effect while a thread is 88 * running. If the thread blocks, other threads can run holding the same 89 * token(s). The tokens are reacquired when the original thread resumes. 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 95 * interrupts as well as other cpus. This means that your token can only 96 * be (temporarily) lost if you *explicitly* block. 97 * 98 * Tokens are managed through a helper reference structure, lwkt_tokref. Each 99 * thread has a stack of tokref's to keep track of acquired tokens. Multiple 100 * tokref's may reference the same token. 101 */ 102 103 typedef struct lwkt_token { 104 struct lwkt_tokref *t_ref; /* Owning ref or NULL */ 105 intptr_t t_flags; /* MP lock required */ 106 long t_collisions; /* Collision counter */ 107 cpumask_t t_collmask; /* Collision cpu mask for resched */ 108 const char *t_desc; /* Descriptive name */ 109 } lwkt_token; 110 111 #define LWKT_TOKEN_MPSAFE 0x0001 112 113 /* 114 * Static initialization for a lwkt_token. 115 * UP - Not MPSAFE (full MP lock will also be acquired) 116 * MP - Is MPSAFE (only the token will be acquired) 117 */ 118 #define LWKT_TOKEN_UP_INITIALIZER(name) \ 119 { \ 120 .t_ref = NULL, \ 121 .t_flags = 0, \ 122 .t_collisions = 0, \ 123 .t_collmask = 0, \ 124 .t_desc = #name \ 125 } 126 127 #define LWKT_TOKEN_MP_INITIALIZER(name) \ 128 { \ 129 .t_ref = NULL, \ 130 .t_flags = LWKT_TOKEN_MPSAFE, \ 131 .t_collisions = 0, \ 132 .t_collmask = 0, \ 133 .t_desc = #name \ 134 } 135 136 /* 137 * Assert that a particular token is held 138 */ 139 #define LWKT_TOKEN_HELD(tok) _lwkt_token_held(tok, curthread) 140 141 #define ASSERT_LWKT_TOKEN_HELD(tok) \ 142 KKASSERT(LWKT_TOKEN_HELD(tok)) 143 144 #define ASSERT_NO_TOKENS_HELD(td) \ 145 KKASSERT((td)->td_toks_stop == &td->td_toks_array[0]) 146 147 /* 148 * Assert that a particular token is held and we are in a hard 149 * code execution section (interrupt, ipi, or hard code section). 150 * Hard code sections are not allowed to block or potentially block. 151 * e.g. lwkt_gettoken() would only be ok if the token were already 152 * held. 153 */ 154 #define ASSERT_LWKT_TOKEN_HARD(tok) \ 155 do { \ 156 globaldata_t zgd __debugvar = mycpu; \ 157 KKASSERT((tok)->t_ref && \ 158 (tok)->t_ref->tr_owner == zgd->gd_curthread && \ 159 zgd->gd_intr_nesting_level > 0); \ 160 } while(0) 161 162 /* 163 * Assert that a particular token is held and we are in a normal 164 * critical section. Critical sections will not be preempted but 165 * can explicitly block (tsleep, lwkt_gettoken, etc). 166 */ 167 #define ASSERT_LWKT_TOKEN_CRIT(tok) \ 168 do { \ 169 globaldata_t zgd __debugvar = mycpu; \ 170 KKASSERT((tok)->t_ref && \ 171 (tok)->t_ref->tr_owner == zgd->gd_curthread && \ 172 zgd->gd_curthread->td_critcount > 0); \ 173 } while(0) 174 175 struct lwkt_tokref { 176 lwkt_token_t tr_tok; /* token in question */ 177 struct thread *tr_owner; /* me */ 178 intptr_t tr_flags; /* copy of t_flags */ 179 const void *tr_stallpc; /* stalled at pc */ 180 }; 181 182 #define MAXCPUFIFO 16 /* power of 2 */ 183 #define MAXCPUFIFO_MASK (MAXCPUFIFO - 1) 184 #define LWKT_MAXTOKENS 32 /* max tokens beneficially held by thread */ 185 186 /* 187 * Always cast to ipifunc_t when registering an ipi. The actual ipi function 188 * is called with both the data and an interrupt frame, but the ipi function 189 * that is registered might only declare a data argument. 190 */ 191 typedef void (*ipifunc1_t)(void *arg); 192 typedef void (*ipifunc2_t)(void *arg, int arg2); 193 typedef void (*ipifunc3_t)(void *arg, int arg2, struct intrframe *frame); 194 195 typedef struct lwkt_ipiq { 196 int ip_rindex; /* only written by target cpu */ 197 int ip_xindex; /* written by target, indicates completion */ 198 int ip_windex; /* only written by source cpu */ 199 ipifunc3_t ip_func[MAXCPUFIFO]; 200 void *ip_arg1[MAXCPUFIFO]; 201 int ip_arg2[MAXCPUFIFO]; 202 u_int ip_npoll; /* synchronization to avoid excess IPIs */ 203 } lwkt_ipiq; 204 205 /* 206 * CPU Synchronization structure. See lwkt_cpusync_start() and 207 * lwkt_cpusync_finish() for more information. 208 */ 209 typedef void (*cpusync_func_t)(lwkt_cpusync_t poll); 210 typedef void (*cpusync_func2_t)(void *data); 211 212 struct lwkt_cpusync { 213 cpusync_func_t cs_run_func; /* run (tandem w/ acquire) */ 214 cpusync_func_t cs_fin1_func; /* fin1 (synchronized) */ 215 cpusync_func2_t cs_fin2_func; /* fin2 (tandem w/ release) */ 216 void *cs_data; 217 int cs_maxcount; 218 volatile int cs_count; 219 cpumask_t cs_mask; 220 }; 221 222 /* 223 * The standard message and queue structure used for communications between 224 * cpus. Messages are typically queued via a machine-specific non-linked 225 * FIFO matrix allowing any cpu to send a message to any other cpu without 226 * blocking. 227 */ 228 typedef struct lwkt_cpu_msg { 229 void (*cm_func)(lwkt_cpu_msg_t msg); /* primary dispatch function */ 230 int cm_code; /* request code if applicable */ 231 int cm_cpu; /* reply to cpu */ 232 thread_t cm_originator; /* originating thread for wakeup */ 233 } lwkt_cpu_msg; 234 235 /* 236 * Thread structure. Note that ownership of a thread structure is special 237 * cased and there is no 'token'. A thread is always owned by the cpu 238 * represented by td_gd, any manipulation of the thread by some other cpu 239 * must be done through cpu_*msg() functions. e.g. you could request 240 * ownership of a thread that way, or hand a thread off to another cpu. 241 * 242 * NOTE: td_ucred is synchronized from the p_ucred on user->kernel syscall, 243 * trap, and AST/signal transitions to provide a stable ucred for 244 * (primarily) system calls. This field will be NULL for pure kernel 245 * threads. 246 */ 247 struct md_intr_info; 248 struct caps_kinfo; 249 250 struct thread { 251 TAILQ_ENTRY(thread) td_threadq; 252 TAILQ_ENTRY(thread) td_allq; 253 TAILQ_ENTRY(thread) td_sleepq; 254 lwkt_port td_msgport; /* built-in message port for replies */ 255 struct lwp *td_lwp; /* (optional) associated lwp */ 256 struct proc *td_proc; /* (optional) associated process */ 257 struct pcb *td_pcb; /* points to pcb and top of kstack */ 258 struct globaldata *td_gd; /* associated with this cpu */ 259 const char *td_wmesg; /* string name for blockage */ 260 const volatile void *td_wchan; /* waiting on channel */ 261 int td_pri; /* 0-31, 31=highest priority (note 1) */ 262 int td_critcount; /* critical section priority */ 263 int td_flags; /* TDF flags */ 264 int td_wdomain; /* domain for wchan address (typ 0) */ 265 void (*td_preemptable)(struct thread *td, int critcount); 266 void (*td_release)(struct thread *td); 267 char *td_kstack; /* kernel stack */ 268 int td_kstack_size; /* size of kernel stack */ 269 char *td_sp; /* kernel stack pointer for LWKT restore */ 270 void (*td_switch)(struct thread *ntd); 271 __uint64_t td_uticks; /* Statclock hits in user mode (uS) */ 272 __uint64_t td_sticks; /* Statclock hits in system mode (uS) */ 273 __uint64_t td_iticks; /* Statclock hits processing intr (uS) */ 274 int td_locks; /* lockmgr lock debugging */ 275 void *td_dsched_priv1; /* priv data for I/O schedulers */ 276 int td_refs; /* hold position in gd_tdallq / hold free */ 277 int td_nest_count; /* prevent splz nesting */ 278 int td_unused01[2]; /* for future fields */ 279 #ifdef SMP 280 int td_cscount; /* cpu synchronization master */ 281 #else 282 int td_cscount_unused; 283 #endif 284 int td_unused02[4]; /* for future fields */ 285 int td_unused03[4]; /* for future fields */ 286 struct iosched_data td_iosdata; /* Dynamic I/O scheduling data */ 287 struct timeval td_start; /* start time for a thread/process */ 288 char td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */ 289 struct thread *td_preempted; /* we preempted this thread */ 290 struct ucred *td_ucred; /* synchronized from p_ucred */ 291 struct caps_kinfo *td_caps; /* list of client and server registrations */ 292 lwkt_tokref_t td_toks_stop; 293 struct lwkt_tokref td_toks_array[LWKT_MAXTOKENS]; 294 int td_fairq_lticks; /* fairq wakeup accumulator reset */ 295 int td_fairq_accum; /* fairq priority accumulator */ 296 const void *td_mplock_stallpc; /* last mplock stall address */ 297 #ifdef DEBUG_CRIT_SECTIONS 298 #define CRIT_DEBUG_ARRAY_SIZE 32 299 #define CRIT_DEBUG_ARRAY_MASK (CRIT_DEBUG_ARRAY_SIZE - 1) 300 const char *td_crit_debug_array[CRIT_DEBUG_ARRAY_SIZE]; 301 int td_crit_debug_index; 302 int td_in_crit_report; 303 #endif 304 struct md_thread td_mach; 305 }; 306 307 #define td_toks_base td_toks_array[0] 308 #define td_toks_end td_toks_array[LWKT_MAXTOKENS] 309 310 #define TD_TOKS_HELD(td) ((td)->td_toks_stop != &(td)->td_toks_base) 311 #define TD_TOKS_NOT_HELD(td) ((td)->td_toks_stop == &(td)->td_toks_base) 312 313 /* 314 * Thread flags. Note that TDF_RUNNING is cleared on the old thread after 315 * we switch to the new one, which is necessary because LWKTs don't need 316 * to hold the BGL. This flag is used by the exit code and the managed 317 * thread migration code. Note in addition that preemption will cause 318 * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING 319 * must also check TDF_PREEMPT_LOCK. 320 * 321 * LWKT threads stay on their (per-cpu) run queue while running, not to 322 * be confused with user processes which are removed from the user scheduling 323 * run queue while actually running. 324 * 325 * td_threadq can represent the thread on one of three queues... the LWKT 326 * run queue, a tsleep queue, or an lwkt blocking queue. The LWKT subsystem 327 * does not allow a thread to be scheduled if it already resides on some 328 * queue. 329 */ 330 #define TDF_RUNNING 0x0001 /* thread still active */ 331 #define TDF_RUNQ 0x0002 /* on an LWKT run queue */ 332 #define TDF_PREEMPT_LOCK 0x0004 /* I have been preempted */ 333 #define TDF_PREEMPT_DONE 0x0008 /* acknowledge preemption complete */ 334 #define TDF_UNUSED00000010 0x0010 335 #define TDF_MIGRATING 0x0020 /* thread is being migrated */ 336 #define TDF_SINTR 0x0040 /* interruptability hint for 'ps' */ 337 #define TDF_TSLEEPQ 0x0080 /* on a tsleep wait queue */ 338 339 #define TDF_SYSTHREAD 0x0100 /* allocations may use reserve */ 340 #define TDF_ALLOCATED_THREAD 0x0200 /* objcache allocated thread */ 341 #define TDF_ALLOCATED_STACK 0x0400 /* objcache allocated stack */ 342 #define TDF_VERBOSE 0x0800 /* verbose on exit */ 343 #define TDF_DEADLKTREAT 0x1000 /* special lockmgr deadlock treatment */ 344 #define TDF_STOPREQ 0x2000 /* suspend_kproc */ 345 #define TDF_WAKEREQ 0x4000 /* resume_kproc */ 346 #define TDF_TIMEOUT 0x8000 /* tsleep timeout */ 347 #define TDF_INTTHREAD 0x00010000 /* interrupt thread */ 348 #define TDF_TSLEEP_DESCHEDULED 0x00020000 /* tsleep core deschedule */ 349 #define TDF_BLOCKED 0x00040000 /* Thread is blocked */ 350 #define TDF_PANICWARN 0x00080000 /* panic warning in switch */ 351 #define TDF_BLOCKQ 0x00100000 /* on block queue */ 352 #define TDF_UNUSED00200000 0x00200000 353 #define TDF_EXITING 0x00400000 /* thread exiting */ 354 #define TDF_USINGFP 0x00800000 /* thread using fp coproc */ 355 #define TDF_KERNELFP 0x01000000 /* kernel using fp coproc */ 356 #define TDF_UNUSED02000000 0x02000000 357 #define TDF_CRYPTO 0x04000000 /* crypto thread */ 358 #define TDF_MARKER 0x80000000 /* fairq marker thread */ 359 360 /* 361 * Thread priorities. Typically only one thread from any given 362 * user process scheduling queue is on the LWKT run queue at a time. 363 * Remember that there is one LWKT run queue per cpu. 364 * 365 * Critical sections are handled by bumping td_pri above TDPRI_MAX, which 366 * causes interrupts to be masked as they occur. When this occurs a 367 * rollup flag will be set in mycpu->gd_reqflags. 368 */ 369 #define TDPRI_IDLE_THREAD 0 /* the idle thread */ 370 #define TDPRI_IDLE_WORK 1 /* idle work (page zero, etc) */ 371 #define TDPRI_USER_SCHEDULER 2 /* user scheduler helper */ 372 #define TDPRI_USER_IDLE 4 /* user scheduler idle */ 373 #define TDPRI_USER_NORM 6 /* user scheduler normal */ 374 #define TDPRI_USER_REAL 8 /* user scheduler real time */ 375 #define TDPRI_KERN_LPSCHED 9 /* scheduler helper for userland sch */ 376 #define TDPRI_KERN_USER 10 /* kernel / block in syscall */ 377 #define TDPRI_KERN_DAEMON 12 /* kernel daemon (pageout, etc) */ 378 #define TDPRI_SOFT_NORM 14 /* kernel / normal */ 379 #define TDPRI_SOFT_TIMER 16 /* kernel / timer */ 380 #define TDPRI_EXITING 19 /* exiting thread */ 381 #define TDPRI_INT_SUPPORT 20 /* kernel / high priority support */ 382 #define TDPRI_INT_LOW 27 /* low priority interrupt */ 383 #define TDPRI_INT_MED 28 /* medium priority interrupt */ 384 #define TDPRI_INT_HIGH 29 /* high priority interrupt */ 385 #define TDPRI_MAX 31 386 387 /* 388 * Scale is the approximate number of ticks for which we desire the 389 * entire gd_tdrunq to get service. With hz = 100 a scale of 8 is 80ms. 390 * 391 * Setting this value too small will result in inefficient switching 392 * rates. 393 */ 394 #define TDFAIRQ_SCALE 8 395 #define TDFAIRQ_MAX(gd) ((gd)->gd_fairq_total_pri * TDFAIRQ_SCALE) 396 397 #define LWKT_THREAD_STACK (UPAGES * PAGE_SIZE) 398 399 #define CACHE_NTHREADS 6 400 401 #define IN_CRITICAL_SECT(td) ((td)->td_critcount) 402 403 #ifdef _KERNEL 404 405 /* 406 * Global tokens 407 */ 408 extern struct lwkt_token mp_token; 409 extern struct lwkt_token pmap_token; 410 extern struct lwkt_token dev_token; 411 extern struct lwkt_token vm_token; 412 extern struct lwkt_token vmspace_token; 413 extern struct lwkt_token kvm_token; 414 extern struct lwkt_token proc_token; 415 extern struct lwkt_token tty_token; 416 extern struct lwkt_token vnode_token; 417 extern struct lwkt_token vmobj_token; 418 419 /* 420 * Procedures 421 */ 422 extern void lwkt_init(void); 423 extern struct thread *lwkt_alloc_thread(struct thread *, int, int, int); 424 extern void lwkt_init_thread(struct thread *, void *, int, int, 425 struct globaldata *); 426 extern void lwkt_set_comm(thread_t, const char *, ...) __printflike(2, 3); 427 extern void lwkt_wait_free(struct thread *); 428 extern void lwkt_free_thread(struct thread *); 429 extern void lwkt_gdinit(struct globaldata *); 430 extern void lwkt_switch(void); 431 extern void lwkt_preempt(thread_t, int); 432 extern void lwkt_schedule(thread_t); 433 extern void lwkt_schedule_noresched(thread_t); 434 extern void lwkt_schedule_self(thread_t); 435 extern void lwkt_deschedule(thread_t); 436 extern void lwkt_deschedule_self(thread_t); 437 extern void lwkt_yield(void); 438 extern void lwkt_user_yield(void); 439 extern void lwkt_token_wait(void); 440 extern void lwkt_hold(thread_t); 441 extern void lwkt_rele(thread_t); 442 extern void lwkt_passive_release(thread_t); 443 extern void lwkt_maybe_splz(thread_t); 444 445 extern void lwkt_gettoken(lwkt_token_t); 446 extern void lwkt_gettoken_hard(lwkt_token_t); 447 extern int lwkt_trytoken(lwkt_token_t); 448 extern void lwkt_reltoken(lwkt_token_t); 449 extern void lwkt_reltoken_hard(lwkt_token_t); 450 extern int lwkt_cnttoken(lwkt_token_t, thread_t); 451 extern int lwkt_getalltokens(thread_t); 452 extern void lwkt_relalltokens(thread_t); 453 extern void lwkt_drain_token_requests(void); 454 extern void lwkt_token_init(lwkt_token_t, int, const char *); 455 extern void lwkt_token_uninit(lwkt_token_t); 456 457 extern void lwkt_token_pool_init(void); 458 extern lwkt_token_t lwkt_token_pool_lookup(void *); 459 extern lwkt_token_t lwkt_getpooltoken(void *); 460 extern void lwkt_relpooltoken(void *); 461 462 extern void lwkt_setpri(thread_t, int); 463 extern void lwkt_setpri_initial(thread_t, int); 464 extern void lwkt_setpri_self(int); 465 extern void lwkt_fairq_schedulerclock(thread_t td); 466 extern void lwkt_fairq_setpri_self(int pri); 467 extern int lwkt_fairq_push(int pri); 468 extern void lwkt_fairq_pop(int pri); 469 extern void lwkt_fairq_yield(void); 470 extern void lwkt_setcpu_self(struct globaldata *); 471 extern void lwkt_migratecpu(int); 472 473 #ifdef SMP 474 475 extern void lwkt_giveaway(struct thread *); 476 extern void lwkt_acquire(struct thread *); 477 extern int lwkt_send_ipiq3(struct globaldata *, ipifunc3_t, void *, int); 478 extern int lwkt_send_ipiq3_passive(struct globaldata *, ipifunc3_t, 479 void *, int); 480 extern int lwkt_send_ipiq3_nowait(struct globaldata *, ipifunc3_t, 481 void *, int); 482 extern int lwkt_send_ipiq3_bycpu(int, ipifunc3_t, void *, int); 483 extern int lwkt_send_ipiq3_mask(cpumask_t, ipifunc3_t, void *, int); 484 extern void lwkt_wait_ipiq(struct globaldata *, int); 485 extern int lwkt_seq_ipiq(struct globaldata *); 486 extern void lwkt_process_ipiq(void); 487 extern void lwkt_process_ipiq_frame(struct intrframe *); 488 extern void lwkt_smp_stopped(void); 489 extern void lwkt_synchronize_ipiqs(const char *); 490 491 #endif /* SMP */ 492 493 extern void lwkt_cpusync_simple(cpumask_t, cpusync_func_t, void *); 494 extern void lwkt_cpusync_fastdata(cpumask_t, cpusync_func2_t, void *); 495 extern void lwkt_cpusync_start(cpumask_t, lwkt_cpusync_t); 496 extern void lwkt_cpusync_add(cpumask_t, lwkt_cpusync_t); 497 extern void lwkt_cpusync_finish(lwkt_cpusync_t); 498 499 extern void crit_panic(void) __dead2; 500 extern struct lwp *lwkt_preempted_proc(void); 501 502 extern int lwkt_create (void (*func)(void *), void *, struct thread **, 503 struct thread *, int, int, 504 const char *, ...) __printflike(7, 8); 505 extern void lwkt_exit (void) __dead2; 506 extern void lwkt_remove_tdallq (struct thread *); 507 508 #endif 509 510 #endif 511 512