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)(void *arg); 210 211 struct lwkt_cpusync { 212 cpumask_t cs_mask; /* cpus running the sync */ 213 cpumask_t cs_mack; /* mask acknowledge */ 214 cpusync_func_t cs_func; /* function to execute */ 215 void *cs_data; /* function data */ 216 }; 217 218 /* 219 * The standard message and queue structure used for communications between 220 * cpus. Messages are typically queued via a machine-specific non-linked 221 * FIFO matrix allowing any cpu to send a message to any other cpu without 222 * blocking. 223 */ 224 typedef struct lwkt_cpu_msg { 225 void (*cm_func)(lwkt_cpu_msg_t msg); /* primary dispatch function */ 226 int cm_code; /* request code if applicable */ 227 int cm_cpu; /* reply to cpu */ 228 thread_t cm_originator; /* originating thread for wakeup */ 229 } lwkt_cpu_msg; 230 231 /* 232 * Thread structure. Note that ownership of a thread structure is special 233 * cased and there is no 'token'. A thread is always owned by the cpu 234 * represented by td_gd, any manipulation of the thread by some other cpu 235 * must be done through cpu_*msg() functions. e.g. you could request 236 * ownership of a thread that way, or hand a thread off to another cpu. 237 * 238 * NOTE: td_ucred is synchronized from the p_ucred on user->kernel syscall, 239 * trap, and AST/signal transitions to provide a stable ucred for 240 * (primarily) system calls. This field will be NULL for pure kernel 241 * threads. 242 */ 243 struct md_intr_info; 244 struct caps_kinfo; 245 246 struct thread { 247 TAILQ_ENTRY(thread) td_threadq; 248 TAILQ_ENTRY(thread) td_allq; 249 TAILQ_ENTRY(thread) td_sleepq; 250 lwkt_port td_msgport; /* built-in message port for replies */ 251 struct lwp *td_lwp; /* (optional) associated lwp */ 252 struct proc *td_proc; /* (optional) associated process */ 253 struct pcb *td_pcb; /* points to pcb and top of kstack */ 254 struct globaldata *td_gd; /* associated with this cpu */ 255 const char *td_wmesg; /* string name for blockage */ 256 const volatile void *td_wchan; /* waiting on channel */ 257 int td_pri; /* 0-31, 31=highest priority (note 1) */ 258 int td_critcount; /* critical section priority */ 259 int td_flags; /* TDF flags */ 260 int td_wdomain; /* domain for wchan address (typ 0) */ 261 void (*td_preemptable)(struct thread *td, int critcount); 262 void (*td_release)(struct thread *td); 263 char *td_kstack; /* kernel stack */ 264 int td_kstack_size; /* size of kernel stack */ 265 char *td_sp; /* kernel stack pointer for LWKT restore */ 266 void (*td_switch)(struct thread *ntd); 267 __uint64_t td_uticks; /* Statclock hits in user mode (uS) */ 268 __uint64_t td_sticks; /* Statclock hits in system mode (uS) */ 269 __uint64_t td_iticks; /* Statclock hits processing intr (uS) */ 270 int td_locks; /* lockmgr lock debugging */ 271 void *td_dsched_priv1; /* priv data for I/O schedulers */ 272 int td_refs; /* hold position in gd_tdallq / hold free */ 273 int td_nest_count; /* prevent splz nesting */ 274 int td_unused01[2]; /* for future fields */ 275 #ifdef SMP 276 int td_cscount; /* cpu synchronization master */ 277 #else 278 int td_cscount_unused; 279 #endif 280 int td_unused02[4]; /* for future fields */ 281 int td_unused03[4]; /* for future fields */ 282 struct iosched_data td_iosdata; /* Dynamic I/O scheduling data */ 283 struct timeval td_start; /* start time for a thread/process */ 284 char td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */ 285 struct thread *td_preempted; /* we preempted this thread */ 286 struct ucred *td_ucred; /* synchronized from p_ucred */ 287 struct caps_kinfo *td_caps; /* list of client and server registrations */ 288 lwkt_tokref_t td_toks_stop; 289 struct lwkt_tokref td_toks_array[LWKT_MAXTOKENS]; 290 int td_fairq_lticks; /* fairq wakeup accumulator reset */ 291 int td_fairq_accum; /* fairq priority accumulator */ 292 const void *td_mplock_stallpc; /* last mplock stall address */ 293 #ifdef DEBUG_CRIT_SECTIONS 294 #define CRIT_DEBUG_ARRAY_SIZE 32 295 #define CRIT_DEBUG_ARRAY_MASK (CRIT_DEBUG_ARRAY_SIZE - 1) 296 const char *td_crit_debug_array[CRIT_DEBUG_ARRAY_SIZE]; 297 int td_crit_debug_index; 298 int td_in_crit_report; 299 #endif 300 struct md_thread td_mach; 301 #ifdef DEBUG_LOCKS 302 #define SPINLOCK_DEBUG_ARRAY_SIZE 32 303 int td_spinlock_stack_id[SPINLOCK_DEBUG_ARRAY_SIZE]; 304 struct spinlock *td_spinlock_stack[SPINLOCK_DEBUG_ARRAY_SIZE]; 305 void *td_spinlock_caller_pc[SPINLOCK_DEBUG_ARRAY_SIZE]; 306 #endif 307 }; 308 309 #define td_toks_base td_toks_array[0] 310 #define td_toks_end td_toks_array[LWKT_MAXTOKENS] 311 312 #define TD_TOKS_HELD(td) ((td)->td_toks_stop != &(td)->td_toks_base) 313 #define TD_TOKS_NOT_HELD(td) ((td)->td_toks_stop == &(td)->td_toks_base) 314 315 /* 316 * Thread flags. Note that TDF_RUNNING is cleared on the old thread after 317 * we switch to the new one, which is necessary because LWKTs don't need 318 * to hold the BGL. This flag is used by the exit code and the managed 319 * thread migration code. Note in addition that preemption will cause 320 * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING 321 * must also check TDF_PREEMPT_LOCK. 322 * 323 * LWKT threads stay on their (per-cpu) run queue while running, not to 324 * be confused with user processes which are removed from the user scheduling 325 * run queue while actually running. 326 * 327 * td_threadq can represent the thread on one of three queues... the LWKT 328 * run queue, a tsleep queue, or an lwkt blocking queue. The LWKT subsystem 329 * does not allow a thread to be scheduled if it already resides on some 330 * queue. 331 */ 332 #define TDF_RUNNING 0x0001 /* thread still active */ 333 #define TDF_RUNQ 0x0002 /* on an LWKT run queue */ 334 #define TDF_PREEMPT_LOCK 0x0004 /* I have been preempted */ 335 #define TDF_PREEMPT_DONE 0x0008 /* acknowledge preemption complete */ 336 #define TDF_UNUSED00000010 0x0010 337 #define TDF_MIGRATING 0x0020 /* thread is being migrated */ 338 #define TDF_SINTR 0x0040 /* interruptability hint for 'ps' */ 339 #define TDF_TSLEEPQ 0x0080 /* on a tsleep wait queue */ 340 341 #define TDF_SYSTHREAD 0x0100 /* allocations may use reserve */ 342 #define TDF_ALLOCATED_THREAD 0x0200 /* objcache allocated thread */ 343 #define TDF_ALLOCATED_STACK 0x0400 /* objcache allocated stack */ 344 #define TDF_VERBOSE 0x0800 /* verbose on exit */ 345 #define TDF_DEADLKTREAT 0x1000 /* special lockmgr deadlock treatment */ 346 #define TDF_STOPREQ 0x2000 /* suspend_kproc */ 347 #define TDF_WAKEREQ 0x4000 /* resume_kproc */ 348 #define TDF_TIMEOUT 0x8000 /* tsleep timeout */ 349 #define TDF_INTTHREAD 0x00010000 /* interrupt thread */ 350 #define TDF_TSLEEP_DESCHEDULED 0x00020000 /* tsleep core deschedule */ 351 #define TDF_BLOCKED 0x00040000 /* Thread is blocked */ 352 #define TDF_PANICWARN 0x00080000 /* panic warning in switch */ 353 #define TDF_BLOCKQ 0x00100000 /* on block queue */ 354 #define TDF_UNUSED00200000 0x00200000 355 #define TDF_EXITING 0x00400000 /* thread exiting */ 356 #define TDF_USINGFP 0x00800000 /* thread using fp coproc */ 357 #define TDF_KERNELFP 0x01000000 /* kernel using fp coproc */ 358 #define TDF_UNUSED02000000 0x02000000 359 #define TDF_CRYPTO 0x04000000 /* crypto thread */ 360 #define TDF_MARKER 0x80000000 /* fairq marker thread */ 361 362 /* 363 * Thread priorities. Typically only one thread from any given 364 * user process scheduling queue is on the LWKT run queue at a time. 365 * Remember that there is one LWKT run queue per cpu. 366 * 367 * Critical sections are handled by bumping td_pri above TDPRI_MAX, which 368 * causes interrupts to be masked as they occur. When this occurs a 369 * rollup flag will be set in mycpu->gd_reqflags. 370 */ 371 #define TDPRI_IDLE_THREAD 0 /* the idle thread */ 372 #define TDPRI_IDLE_WORK 1 /* idle work (page zero, etc) */ 373 #define TDPRI_USER_SCHEDULER 2 /* user scheduler helper */ 374 #define TDPRI_USER_IDLE 4 /* user scheduler idle */ 375 #define TDPRI_USER_NORM 6 /* user scheduler normal */ 376 #define TDPRI_USER_REAL 8 /* user scheduler real time */ 377 #define TDPRI_KERN_LPSCHED 9 /* scheduler helper for userland sch */ 378 #define TDPRI_KERN_USER 10 /* kernel / block in syscall */ 379 #define TDPRI_KERN_DAEMON 12 /* kernel daemon (pageout, etc) */ 380 #define TDPRI_SOFT_NORM 14 /* kernel / normal */ 381 #define TDPRI_SOFT_TIMER 16 /* kernel / timer */ 382 #define TDPRI_EXITING 19 /* exiting thread */ 383 #define TDPRI_INT_SUPPORT 20 /* kernel / high priority support */ 384 #define TDPRI_INT_LOW 27 /* low priority interrupt */ 385 #define TDPRI_INT_MED 28 /* medium priority interrupt */ 386 #define TDPRI_INT_HIGH 29 /* high priority interrupt */ 387 #define TDPRI_MAX 31 388 389 /* 390 * Scale is the approximate number of ticks for which we desire the 391 * entire gd_tdrunq to get service. With hz = 100 a scale of 8 is 80ms. 392 * 393 * Setting this value too small will result in inefficient switching 394 * rates. 395 */ 396 #define TDFAIRQ_SCALE 8 397 #define TDFAIRQ_MAX(gd) ((gd)->gd_fairq_total_pri * TDFAIRQ_SCALE) 398 399 #define LWKT_THREAD_STACK (UPAGES * PAGE_SIZE) 400 401 #define CACHE_NTHREADS 6 402 403 #define IN_CRITICAL_SECT(td) ((td)->td_critcount) 404 405 #ifdef _KERNEL 406 407 /* 408 * Global tokens 409 */ 410 extern struct lwkt_token mp_token; 411 extern struct lwkt_token pmap_token; 412 extern struct lwkt_token dev_token; 413 extern struct lwkt_token vm_token; 414 extern struct lwkt_token vmspace_token; 415 extern struct lwkt_token kvm_token; 416 extern struct lwkt_token proc_token; 417 extern struct lwkt_token tty_token; 418 extern struct lwkt_token vnode_token; 419 extern struct lwkt_token vmobj_token; 420 421 /* 422 * Procedures 423 */ 424 extern void lwkt_init(void); 425 extern struct thread *lwkt_alloc_thread(struct thread *, int, int, int); 426 extern void lwkt_init_thread(struct thread *, void *, int, int, 427 struct globaldata *); 428 extern void lwkt_set_comm(thread_t, const char *, ...) __printflike(2, 3); 429 extern void lwkt_wait_free(struct thread *); 430 extern void lwkt_free_thread(struct thread *); 431 extern void lwkt_gdinit(struct globaldata *); 432 extern void lwkt_switch(void); 433 extern void lwkt_preempt(thread_t, int); 434 extern void lwkt_schedule(thread_t); 435 extern void lwkt_schedule_noresched(thread_t); 436 extern void lwkt_schedule_self(thread_t); 437 extern void lwkt_deschedule(thread_t); 438 extern void lwkt_deschedule_self(thread_t); 439 extern void lwkt_yield(void); 440 extern void lwkt_user_yield(void); 441 extern void lwkt_token_wait(void); 442 extern void lwkt_hold(thread_t); 443 extern void lwkt_rele(thread_t); 444 extern void lwkt_passive_release(thread_t); 445 extern void lwkt_maybe_splz(thread_t); 446 447 extern void lwkt_gettoken(lwkt_token_t); 448 extern void lwkt_gettoken_hard(lwkt_token_t); 449 extern int lwkt_trytoken(lwkt_token_t); 450 extern void lwkt_reltoken(lwkt_token_t); 451 extern void lwkt_reltoken_hard(lwkt_token_t); 452 extern int lwkt_cnttoken(lwkt_token_t, thread_t); 453 extern int lwkt_getalltokens(thread_t); 454 extern void lwkt_relalltokens(thread_t); 455 extern void lwkt_drain_token_requests(void); 456 extern void lwkt_token_init(lwkt_token_t, int, const char *); 457 extern void lwkt_token_uninit(lwkt_token_t); 458 459 extern void lwkt_token_pool_init(void); 460 extern lwkt_token_t lwkt_token_pool_lookup(void *); 461 extern lwkt_token_t lwkt_getpooltoken(void *); 462 extern void lwkt_relpooltoken(void *); 463 464 extern void lwkt_setpri(thread_t, int); 465 extern void lwkt_setpri_initial(thread_t, int); 466 extern void lwkt_setpri_self(int); 467 extern void lwkt_fairq_schedulerclock(thread_t td); 468 extern void lwkt_fairq_setpri_self(int pri); 469 extern int lwkt_fairq_push(int pri); 470 extern void lwkt_fairq_pop(int pri); 471 extern void lwkt_fairq_yield(void); 472 extern void lwkt_setcpu_self(struct globaldata *); 473 extern void lwkt_migratecpu(int); 474 475 #ifdef SMP 476 477 extern void lwkt_giveaway(struct thread *); 478 extern void lwkt_acquire(struct thread *); 479 extern int lwkt_send_ipiq3(struct globaldata *, ipifunc3_t, void *, int); 480 extern int lwkt_send_ipiq3_passive(struct globaldata *, ipifunc3_t, 481 void *, int); 482 extern int lwkt_send_ipiq3_nowait(struct globaldata *, ipifunc3_t, 483 void *, int); 484 extern int lwkt_send_ipiq3_bycpu(int, ipifunc3_t, void *, int); 485 extern int lwkt_send_ipiq3_mask(cpumask_t, ipifunc3_t, void *, int); 486 extern void lwkt_wait_ipiq(struct globaldata *, int); 487 extern int lwkt_seq_ipiq(struct globaldata *); 488 extern void lwkt_process_ipiq(void); 489 extern void lwkt_process_ipiq_frame(struct intrframe *); 490 extern void lwkt_smp_stopped(void); 491 extern void lwkt_synchronize_ipiqs(const char *); 492 493 #endif /* SMP */ 494 495 /* lwkt_cpusync_init() - inline function in sys/thread2.h */ 496 extern void lwkt_cpusync_simple(cpumask_t, cpusync_func_t, void *); 497 extern void lwkt_cpusync_interlock(lwkt_cpusync_t); 498 extern void lwkt_cpusync_deinterlock(lwkt_cpusync_t); 499 500 extern void crit_panic(void) __dead2; 501 extern struct lwp *lwkt_preempted_proc(void); 502 503 extern int lwkt_create (void (*func)(void *), void *, struct thread **, 504 struct thread *, int, int, 505 const char *, ...) __printflike(7, 8); 506 extern void lwkt_exit (void) __dead2; 507 extern void lwkt_remove_tdallq (struct thread *); 508 509 #endif 510 511 #endif 512 513