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