1 #ifndef _LINUX_SCHED_H 2 #define _LINUX_SCHED_H 3 4 #include <asm/param.h> /* for HZ */ 5 6 #include <linux/config.h> 7 #include <linux/capability.h> 8 #include <linux/threads.h> 9 #include <linux/kernel.h> 10 #include <linux/types.h> 11 #include <linux/timex.h> 12 #include <linux/jiffies.h> 13 #include <linux/rbtree.h> 14 #include <linux/thread_info.h> 15 #include <linux/cpumask.h> 16 #include <linux/errno.h> 17 #include <linux/nodemask.h> 18 19 #include <asm/system.h> 20 #include <asm/semaphore.h> 21 #include <asm/page.h> 22 #include <asm/ptrace.h> 23 #include <asm/mmu.h> 24 #include <asm/cputime.h> 25 26 #include <linux/smp.h> 27 #include <linux/sem.h> 28 #include <linux/signal.h> 29 #include <linux/securebits.h> 30 #include <linux/fs_struct.h> 31 #include <linux/compiler.h> 32 #include <linux/completion.h> 33 #include <linux/pid.h> 34 #include <linux/percpu.h> 35 #include <linux/topology.h> 36 #include <linux/seccomp.h> 37 #include <linux/rcupdate.h> 38 #include <linux/futex.h> 39 40 #include <linux/auxvec.h> /* For AT_VECTOR_SIZE */ 41 42 struct exec_domain; 43 44 /* 45 * cloning flags: 46 */ 47 #define CSIGNAL 0x000000ff /* signal mask to be sent at exit */ 48 #define CLONE_VM 0x00000100 /* set if VM shared between processes */ 49 #define CLONE_FS 0x00000200 /* set if fs info shared between processes */ 50 #define CLONE_FILES 0x00000400 /* set if open files shared between processes */ 51 #define CLONE_SIGHAND 0x00000800 /* set if signal handlers and blocked signals shared */ 52 #define CLONE_PTRACE 0x00002000 /* set if we want to let tracing continue on the child too */ 53 #define CLONE_VFORK 0x00004000 /* set if the parent wants the child to wake it up on mm_release */ 54 #define CLONE_PARENT 0x00008000 /* set if we want to have the same parent as the cloner */ 55 #define CLONE_THREAD 0x00010000 /* Same thread group? */ 56 #define CLONE_NEWNS 0x00020000 /* New namespace group? */ 57 #define CLONE_SYSVSEM 0x00040000 /* share system V SEM_UNDO semantics */ 58 #define CLONE_SETTLS 0x00080000 /* create a new TLS for the child */ 59 #define CLONE_PARENT_SETTID 0x00100000 /* set the TID in the parent */ 60 #define CLONE_CHILD_CLEARTID 0x00200000 /* clear the TID in the child */ 61 #define CLONE_DETACHED 0x00400000 /* Unused, ignored */ 62 #define CLONE_UNTRACED 0x00800000 /* set if the tracing process can't force CLONE_PTRACE on this clone */ 63 #define CLONE_CHILD_SETTID 0x01000000 /* set the TID in the child */ 64 #define CLONE_STOPPED 0x02000000 /* Start in stopped state */ 65 66 /* 67 * List of flags we want to share for kernel threads, 68 * if only because they are not used by them anyway. 69 */ 70 #define CLONE_KERNEL (CLONE_FS | CLONE_FILES | CLONE_SIGHAND) 71 72 /* 73 * These are the constant used to fake the fixed-point load-average 74 * counting. Some notes: 75 * - 11 bit fractions expand to 22 bits by the multiplies: this gives 76 * a load-average precision of 10 bits integer + 11 bits fractional 77 * - if you want to count load-averages more often, you need more 78 * precision, or rounding will get you. With 2-second counting freq, 79 * the EXP_n values would be 1981, 2034 and 2043 if still using only 80 * 11 bit fractions. 81 */ 82 extern unsigned long avenrun[]; /* Load averages */ 83 84 #define FSHIFT 11 /* nr of bits of precision */ 85 #define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */ 86 #define LOAD_FREQ (5*HZ) /* 5 sec intervals */ 87 #define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */ 88 #define EXP_5 2014 /* 1/exp(5sec/5min) */ 89 #define EXP_15 2037 /* 1/exp(5sec/15min) */ 90 91 #define CALC_LOAD(load,exp,n) \ 92 load *= exp; \ 93 load += n*(FIXED_1-exp); \ 94 load >>= FSHIFT; 95 96 extern unsigned long total_forks; 97 extern int nr_threads; 98 extern int last_pid; 99 DECLARE_PER_CPU(unsigned long, process_counts); 100 extern int nr_processes(void); 101 extern unsigned long nr_running(void); 102 extern unsigned long nr_uninterruptible(void); 103 extern unsigned long nr_iowait(void); 104 105 #include <linux/time.h> 106 #include <linux/param.h> 107 #include <linux/resource.h> 108 #include <linux/timer.h> 109 #include <linux/hrtimer.h> 110 111 #include <asm/processor.h> 112 113 /* 114 * Task state bitmask. NOTE! These bits are also 115 * encoded in fs/proc/array.c: get_task_state(). 116 * 117 * We have two separate sets of flags: task->state 118 * is about runnability, while task->exit_state are 119 * about the task exiting. Confusing, but this way 120 * modifying one set can't modify the other one by 121 * mistake. 122 */ 123 #define TASK_RUNNING 0 124 #define TASK_INTERRUPTIBLE 1 125 #define TASK_UNINTERRUPTIBLE 2 126 #define TASK_STOPPED 4 127 #define TASK_TRACED 8 128 /* in tsk->exit_state */ 129 #define EXIT_ZOMBIE 16 130 #define EXIT_DEAD 32 131 /* in tsk->state again */ 132 #define TASK_NONINTERACTIVE 64 133 134 #define __set_task_state(tsk, state_value) \ 135 do { (tsk)->state = (state_value); } while (0) 136 #define set_task_state(tsk, state_value) \ 137 set_mb((tsk)->state, (state_value)) 138 139 /* 140 * set_current_state() includes a barrier so that the write of current->state 141 * is correctly serialised wrt the caller's subsequent test of whether to 142 * actually sleep: 143 * 144 * set_current_state(TASK_UNINTERRUPTIBLE); 145 * if (do_i_need_to_sleep()) 146 * schedule(); 147 * 148 * If the caller does not need such serialisation then use __set_current_state() 149 */ 150 #define __set_current_state(state_value) \ 151 do { current->state = (state_value); } while (0) 152 #define set_current_state(state_value) \ 153 set_mb(current->state, (state_value)) 154 155 /* Task command name length */ 156 #define TASK_COMM_LEN 16 157 158 /* 159 * Scheduling policies 160 */ 161 #define SCHED_NORMAL 0 162 #define SCHED_FIFO 1 163 #define SCHED_RR 2 164 #define SCHED_BATCH 3 165 166 struct sched_param { 167 int sched_priority; 168 }; 169 170 #ifdef __KERNEL__ 171 172 #include <linux/spinlock.h> 173 174 /* 175 * This serializes "schedule()" and also protects 176 * the run-queue from deletions/modifications (but 177 * _adding_ to the beginning of the run-queue has 178 * a separate lock). 179 */ 180 extern rwlock_t tasklist_lock; 181 extern spinlock_t mmlist_lock; 182 183 typedef struct task_struct task_t; 184 185 extern void sched_init(void); 186 extern void sched_init_smp(void); 187 extern void init_idle(task_t *idle, int cpu); 188 189 extern cpumask_t nohz_cpu_mask; 190 191 extern void show_state(void); 192 extern void show_regs(struct pt_regs *); 193 194 /* 195 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current 196 * task), SP is the stack pointer of the first frame that should be shown in the back 197 * trace (or NULL if the entire call-chain of the task should be shown). 198 */ 199 extern void show_stack(struct task_struct *task, unsigned long *sp); 200 201 void io_schedule(void); 202 long io_schedule_timeout(long timeout); 203 204 extern void cpu_init (void); 205 extern void trap_init(void); 206 extern void update_process_times(int user); 207 extern void scheduler_tick(void); 208 209 #ifdef CONFIG_DETECT_SOFTLOCKUP 210 extern void softlockup_tick(void); 211 extern void spawn_softlockup_task(void); 212 extern void touch_softlockup_watchdog(void); 213 #else 214 static inline void softlockup_tick(void) 215 { 216 } 217 static inline void spawn_softlockup_task(void) 218 { 219 } 220 static inline void touch_softlockup_watchdog(void) 221 { 222 } 223 #endif 224 225 226 /* Attach to any functions which should be ignored in wchan output. */ 227 #define __sched __attribute__((__section__(".sched.text"))) 228 /* Is this address in the __sched functions? */ 229 extern int in_sched_functions(unsigned long addr); 230 231 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 232 extern signed long FASTCALL(schedule_timeout(signed long timeout)); 233 extern signed long schedule_timeout_interruptible(signed long timeout); 234 extern signed long schedule_timeout_uninterruptible(signed long timeout); 235 asmlinkage void schedule(void); 236 237 struct namespace; 238 239 /* Maximum number of active map areas.. This is a random (large) number */ 240 #define DEFAULT_MAX_MAP_COUNT 65536 241 242 extern int sysctl_max_map_count; 243 244 #include <linux/aio.h> 245 246 extern unsigned long 247 arch_get_unmapped_area(struct file *, unsigned long, unsigned long, 248 unsigned long, unsigned long); 249 extern unsigned long 250 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr, 251 unsigned long len, unsigned long pgoff, 252 unsigned long flags); 253 extern void arch_unmap_area(struct mm_struct *, unsigned long); 254 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long); 255 256 #if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS 257 /* 258 * The mm counters are not protected by its page_table_lock, 259 * so must be incremented atomically. 260 */ 261 #define set_mm_counter(mm, member, value) atomic_long_set(&(mm)->_##member, value) 262 #define get_mm_counter(mm, member) ((unsigned long)atomic_long_read(&(mm)->_##member)) 263 #define add_mm_counter(mm, member, value) atomic_long_add(value, &(mm)->_##member) 264 #define inc_mm_counter(mm, member) atomic_long_inc(&(mm)->_##member) 265 #define dec_mm_counter(mm, member) atomic_long_dec(&(mm)->_##member) 266 typedef atomic_long_t mm_counter_t; 267 268 #else /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */ 269 /* 270 * The mm counters are protected by its page_table_lock, 271 * so can be incremented directly. 272 */ 273 #define set_mm_counter(mm, member, value) (mm)->_##member = (value) 274 #define get_mm_counter(mm, member) ((mm)->_##member) 275 #define add_mm_counter(mm, member, value) (mm)->_##member += (value) 276 #define inc_mm_counter(mm, member) (mm)->_##member++ 277 #define dec_mm_counter(mm, member) (mm)->_##member-- 278 typedef unsigned long mm_counter_t; 279 280 #endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */ 281 282 #define get_mm_rss(mm) \ 283 (get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss)) 284 #define update_hiwater_rss(mm) do { \ 285 unsigned long _rss = get_mm_rss(mm); \ 286 if ((mm)->hiwater_rss < _rss) \ 287 (mm)->hiwater_rss = _rss; \ 288 } while (0) 289 #define update_hiwater_vm(mm) do { \ 290 if ((mm)->hiwater_vm < (mm)->total_vm) \ 291 (mm)->hiwater_vm = (mm)->total_vm; \ 292 } while (0) 293 294 struct mm_struct { 295 struct vm_area_struct * mmap; /* list of VMAs */ 296 struct rb_root mm_rb; 297 struct vm_area_struct * mmap_cache; /* last find_vma result */ 298 unsigned long (*get_unmapped_area) (struct file *filp, 299 unsigned long addr, unsigned long len, 300 unsigned long pgoff, unsigned long flags); 301 void (*unmap_area) (struct mm_struct *mm, unsigned long addr); 302 unsigned long mmap_base; /* base of mmap area */ 303 unsigned long task_size; /* size of task vm space */ 304 unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */ 305 unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */ 306 pgd_t * pgd; 307 atomic_t mm_users; /* How many users with user space? */ 308 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ 309 int map_count; /* number of VMAs */ 310 struct rw_semaphore mmap_sem; 311 spinlock_t page_table_lock; /* Protects page tables and some counters */ 312 313 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung 314 * together off init_mm.mmlist, and are protected 315 * by mmlist_lock 316 */ 317 318 /* Special counters, in some configurations protected by the 319 * page_table_lock, in other configurations by being atomic. 320 */ 321 mm_counter_t _file_rss; 322 mm_counter_t _anon_rss; 323 324 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 325 unsigned long hiwater_vm; /* High-water virtual memory usage */ 326 327 unsigned long total_vm, locked_vm, shared_vm, exec_vm; 328 unsigned long stack_vm, reserved_vm, def_flags, nr_ptes; 329 unsigned long start_code, end_code, start_data, end_data; 330 unsigned long start_brk, brk, start_stack; 331 unsigned long arg_start, arg_end, env_start, env_end; 332 333 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 334 335 unsigned dumpable:2; 336 cpumask_t cpu_vm_mask; 337 338 /* Architecture-specific MM context */ 339 mm_context_t context; 340 341 /* Token based thrashing protection. */ 342 unsigned long swap_token_time; 343 char recent_pagein; 344 345 /* coredumping support */ 346 int core_waiters; 347 struct completion *core_startup_done, core_done; 348 349 /* aio bits */ 350 rwlock_t ioctx_list_lock; 351 struct kioctx *ioctx_list; 352 }; 353 354 struct sighand_struct { 355 atomic_t count; 356 struct k_sigaction action[_NSIG]; 357 spinlock_t siglock; 358 }; 359 360 /* 361 * NOTE! "signal_struct" does not have it's own 362 * locking, because a shared signal_struct always 363 * implies a shared sighand_struct, so locking 364 * sighand_struct is always a proper superset of 365 * the locking of signal_struct. 366 */ 367 struct signal_struct { 368 atomic_t count; 369 atomic_t live; 370 371 wait_queue_head_t wait_chldexit; /* for wait4() */ 372 373 /* current thread group signal load-balancing target: */ 374 task_t *curr_target; 375 376 /* shared signal handling: */ 377 struct sigpending shared_pending; 378 379 /* thread group exit support */ 380 int group_exit_code; 381 /* overloaded: 382 * - notify group_exit_task when ->count is equal to notify_count 383 * - everyone except group_exit_task is stopped during signal delivery 384 * of fatal signals, group_exit_task processes the signal. 385 */ 386 struct task_struct *group_exit_task; 387 int notify_count; 388 389 /* thread group stop support, overloads group_exit_code too */ 390 int group_stop_count; 391 unsigned int flags; /* see SIGNAL_* flags below */ 392 393 /* POSIX.1b Interval Timers */ 394 struct list_head posix_timers; 395 396 /* ITIMER_REAL timer for the process */ 397 struct hrtimer real_timer; 398 struct task_struct *tsk; 399 ktime_t it_real_incr; 400 401 /* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */ 402 cputime_t it_prof_expires, it_virt_expires; 403 cputime_t it_prof_incr, it_virt_incr; 404 405 /* job control IDs */ 406 pid_t pgrp; 407 pid_t tty_old_pgrp; 408 pid_t session; 409 /* boolean value for session group leader */ 410 int leader; 411 412 struct tty_struct *tty; /* NULL if no tty */ 413 414 /* 415 * Cumulative resource counters for dead threads in the group, 416 * and for reaped dead child processes forked by this group. 417 * Live threads maintain their own counters and add to these 418 * in __exit_signal, except for the group leader. 419 */ 420 cputime_t utime, stime, cutime, cstime; 421 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw; 422 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt; 423 424 /* 425 * Cumulative ns of scheduled CPU time for dead threads in the 426 * group, not including a zombie group leader. (This only differs 427 * from jiffies_to_ns(utime + stime) if sched_clock uses something 428 * other than jiffies.) 429 */ 430 unsigned long long sched_time; 431 432 /* 433 * We don't bother to synchronize most readers of this at all, 434 * because there is no reader checking a limit that actually needs 435 * to get both rlim_cur and rlim_max atomically, and either one 436 * alone is a single word that can safely be read normally. 437 * getrlimit/setrlimit use task_lock(current->group_leader) to 438 * protect this instead of the siglock, because they really 439 * have no need to disable irqs. 440 */ 441 struct rlimit rlim[RLIM_NLIMITS]; 442 443 struct list_head cpu_timers[3]; 444 445 /* keep the process-shared keyrings here so that they do the right 446 * thing in threads created with CLONE_THREAD */ 447 #ifdef CONFIG_KEYS 448 struct key *session_keyring; /* keyring inherited over fork */ 449 struct key *process_keyring; /* keyring private to this process */ 450 #endif 451 }; 452 453 /* Context switch must be unlocked if interrupts are to be enabled */ 454 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW 455 # define __ARCH_WANT_UNLOCKED_CTXSW 456 #endif 457 458 /* 459 * Bits in flags field of signal_struct. 460 */ 461 #define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */ 462 #define SIGNAL_STOP_DEQUEUED 0x00000002 /* stop signal dequeued */ 463 #define SIGNAL_STOP_CONTINUED 0x00000004 /* SIGCONT since WCONTINUED reap */ 464 #define SIGNAL_GROUP_EXIT 0x00000008 /* group exit in progress */ 465 466 467 /* 468 * Priority of a process goes from 0..MAX_PRIO-1, valid RT 469 * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH 470 * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority 471 * values are inverted: lower p->prio value means higher priority. 472 * 473 * The MAX_USER_RT_PRIO value allows the actual maximum 474 * RT priority to be separate from the value exported to 475 * user-space. This allows kernel threads to set their 476 * priority to a value higher than any user task. Note: 477 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO. 478 */ 479 480 #define MAX_USER_RT_PRIO 100 481 #define MAX_RT_PRIO MAX_USER_RT_PRIO 482 483 #define MAX_PRIO (MAX_RT_PRIO + 40) 484 485 #define rt_task(p) (unlikely((p)->prio < MAX_RT_PRIO)) 486 487 /* 488 * Some day this will be a full-fledged user tracking system.. 489 */ 490 struct user_struct { 491 atomic_t __count; /* reference count */ 492 atomic_t processes; /* How many processes does this user have? */ 493 atomic_t files; /* How many open files does this user have? */ 494 atomic_t sigpending; /* How many pending signals does this user have? */ 495 #ifdef CONFIG_INOTIFY 496 atomic_t inotify_watches; /* How many inotify watches does this user have? */ 497 atomic_t inotify_devs; /* How many inotify devs does this user have opened? */ 498 #endif 499 /* protected by mq_lock */ 500 unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */ 501 unsigned long locked_shm; /* How many pages of mlocked shm ? */ 502 503 #ifdef CONFIG_KEYS 504 struct key *uid_keyring; /* UID specific keyring */ 505 struct key *session_keyring; /* UID's default session keyring */ 506 #endif 507 508 /* Hash table maintenance information */ 509 struct list_head uidhash_list; 510 uid_t uid; 511 }; 512 513 extern struct user_struct *find_user(uid_t); 514 515 extern struct user_struct root_user; 516 #define INIT_USER (&root_user) 517 518 typedef struct prio_array prio_array_t; 519 struct backing_dev_info; 520 struct reclaim_state; 521 522 #ifdef CONFIG_SCHEDSTATS 523 struct sched_info { 524 /* cumulative counters */ 525 unsigned long cpu_time, /* time spent on the cpu */ 526 run_delay, /* time spent waiting on a runqueue */ 527 pcnt; /* # of timeslices run on this cpu */ 528 529 /* timestamps */ 530 unsigned long last_arrival, /* when we last ran on a cpu */ 531 last_queued; /* when we were last queued to run */ 532 }; 533 534 extern struct file_operations proc_schedstat_operations; 535 #endif 536 537 enum idle_type 538 { 539 SCHED_IDLE, 540 NOT_IDLE, 541 NEWLY_IDLE, 542 MAX_IDLE_TYPES 543 }; 544 545 /* 546 * sched-domains (multiprocessor balancing) declarations: 547 */ 548 #ifdef CONFIG_SMP 549 #define SCHED_LOAD_SCALE 128UL /* increase resolution of load */ 550 551 #define SD_LOAD_BALANCE 1 /* Do load balancing on this domain. */ 552 #define SD_BALANCE_NEWIDLE 2 /* Balance when about to become idle */ 553 #define SD_BALANCE_EXEC 4 /* Balance on exec */ 554 #define SD_BALANCE_FORK 8 /* Balance on fork, clone */ 555 #define SD_WAKE_IDLE 16 /* Wake to idle CPU on task wakeup */ 556 #define SD_WAKE_AFFINE 32 /* Wake task to waking CPU */ 557 #define SD_WAKE_BALANCE 64 /* Perform balancing at task wakeup */ 558 #define SD_SHARE_CPUPOWER 128 /* Domain members share cpu power */ 559 560 struct sched_group { 561 struct sched_group *next; /* Must be a circular list */ 562 cpumask_t cpumask; 563 564 /* 565 * CPU power of this group, SCHED_LOAD_SCALE being max power for a 566 * single CPU. This is read only (except for setup, hotplug CPU). 567 */ 568 unsigned long cpu_power; 569 }; 570 571 struct sched_domain { 572 /* These fields must be setup */ 573 struct sched_domain *parent; /* top domain must be null terminated */ 574 struct sched_group *groups; /* the balancing groups of the domain */ 575 cpumask_t span; /* span of all CPUs in this domain */ 576 unsigned long min_interval; /* Minimum balance interval ms */ 577 unsigned long max_interval; /* Maximum balance interval ms */ 578 unsigned int busy_factor; /* less balancing by factor if busy */ 579 unsigned int imbalance_pct; /* No balance until over watermark */ 580 unsigned long long cache_hot_time; /* Task considered cache hot (ns) */ 581 unsigned int cache_nice_tries; /* Leave cache hot tasks for # tries */ 582 unsigned int per_cpu_gain; /* CPU % gained by adding domain cpus */ 583 unsigned int busy_idx; 584 unsigned int idle_idx; 585 unsigned int newidle_idx; 586 unsigned int wake_idx; 587 unsigned int forkexec_idx; 588 int flags; /* See SD_* */ 589 590 /* Runtime fields. */ 591 unsigned long last_balance; /* init to jiffies. units in jiffies */ 592 unsigned int balance_interval; /* initialise to 1. units in ms. */ 593 unsigned int nr_balance_failed; /* initialise to 0 */ 594 595 #ifdef CONFIG_SCHEDSTATS 596 /* load_balance() stats */ 597 unsigned long lb_cnt[MAX_IDLE_TYPES]; 598 unsigned long lb_failed[MAX_IDLE_TYPES]; 599 unsigned long lb_balanced[MAX_IDLE_TYPES]; 600 unsigned long lb_imbalance[MAX_IDLE_TYPES]; 601 unsigned long lb_gained[MAX_IDLE_TYPES]; 602 unsigned long lb_hot_gained[MAX_IDLE_TYPES]; 603 unsigned long lb_nobusyg[MAX_IDLE_TYPES]; 604 unsigned long lb_nobusyq[MAX_IDLE_TYPES]; 605 606 /* Active load balancing */ 607 unsigned long alb_cnt; 608 unsigned long alb_failed; 609 unsigned long alb_pushed; 610 611 /* SD_BALANCE_EXEC stats */ 612 unsigned long sbe_cnt; 613 unsigned long sbe_balanced; 614 unsigned long sbe_pushed; 615 616 /* SD_BALANCE_FORK stats */ 617 unsigned long sbf_cnt; 618 unsigned long sbf_balanced; 619 unsigned long sbf_pushed; 620 621 /* try_to_wake_up() stats */ 622 unsigned long ttwu_wake_remote; 623 unsigned long ttwu_move_affine; 624 unsigned long ttwu_move_balance; 625 #endif 626 }; 627 628 extern void partition_sched_domains(cpumask_t *partition1, 629 cpumask_t *partition2); 630 631 /* 632 * Maximum cache size the migration-costs auto-tuning code will 633 * search from: 634 */ 635 extern unsigned int max_cache_size; 636 637 #endif /* CONFIG_SMP */ 638 639 640 struct io_context; /* See blkdev.h */ 641 void exit_io_context(void); 642 struct cpuset; 643 644 #define NGROUPS_SMALL 32 645 #define NGROUPS_PER_BLOCK ((int)(PAGE_SIZE / sizeof(gid_t))) 646 struct group_info { 647 int ngroups; 648 atomic_t usage; 649 gid_t small_block[NGROUPS_SMALL]; 650 int nblocks; 651 gid_t *blocks[0]; 652 }; 653 654 /* 655 * get_group_info() must be called with the owning task locked (via task_lock()) 656 * when task != current. The reason being that the vast majority of callers are 657 * looking at current->group_info, which can not be changed except by the 658 * current task. Changing current->group_info requires the task lock, too. 659 */ 660 #define get_group_info(group_info) do { \ 661 atomic_inc(&(group_info)->usage); \ 662 } while (0) 663 664 #define put_group_info(group_info) do { \ 665 if (atomic_dec_and_test(&(group_info)->usage)) \ 666 groups_free(group_info); \ 667 } while (0) 668 669 extern struct group_info *groups_alloc(int gidsetsize); 670 extern void groups_free(struct group_info *group_info); 671 extern int set_current_groups(struct group_info *group_info); 672 extern int groups_search(struct group_info *group_info, gid_t grp); 673 /* access the groups "array" with this macro */ 674 #define GROUP_AT(gi, i) \ 675 ((gi)->blocks[(i)/NGROUPS_PER_BLOCK][(i)%NGROUPS_PER_BLOCK]) 676 677 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK 678 extern void prefetch_stack(struct task_struct*); 679 #else 680 static inline void prefetch_stack(struct task_struct *t) { } 681 #endif 682 683 struct audit_context; /* See audit.c */ 684 struct mempolicy; 685 686 struct task_struct { 687 volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */ 688 struct thread_info *thread_info; 689 atomic_t usage; 690 unsigned long flags; /* per process flags, defined below */ 691 unsigned long ptrace; 692 693 int lock_depth; /* BKL lock depth */ 694 695 #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) 696 int oncpu; 697 #endif 698 int prio, static_prio; 699 struct list_head run_list; 700 prio_array_t *array; 701 702 unsigned short ioprio; 703 unsigned int btrace_seq; 704 705 unsigned long sleep_avg; 706 unsigned long long timestamp, last_ran; 707 unsigned long long sched_time; /* sched_clock time spent running */ 708 int activated; 709 710 unsigned long policy; 711 cpumask_t cpus_allowed; 712 unsigned int time_slice, first_time_slice; 713 714 #ifdef CONFIG_SCHEDSTATS 715 struct sched_info sched_info; 716 #endif 717 718 struct list_head tasks; 719 /* 720 * ptrace_list/ptrace_children forms the list of my children 721 * that were stolen by a ptracer. 722 */ 723 struct list_head ptrace_children; 724 struct list_head ptrace_list; 725 726 struct mm_struct *mm, *active_mm; 727 728 /* task state */ 729 struct linux_binfmt *binfmt; 730 long exit_state; 731 int exit_code, exit_signal; 732 int pdeath_signal; /* The signal sent when the parent dies */ 733 /* ??? */ 734 unsigned long personality; 735 unsigned did_exec:1; 736 pid_t pid; 737 pid_t tgid; 738 /* 739 * pointers to (original) parent process, youngest child, younger sibling, 740 * older sibling, respectively. (p->father can be replaced with 741 * p->parent->pid) 742 */ 743 struct task_struct *real_parent; /* real parent process (when being debugged) */ 744 struct task_struct *parent; /* parent process */ 745 /* 746 * children/sibling forms the list of my children plus the 747 * tasks I'm ptracing. 748 */ 749 struct list_head children; /* list of my children */ 750 struct list_head sibling; /* linkage in my parent's children list */ 751 struct task_struct *group_leader; /* threadgroup leader */ 752 753 /* PID/PID hash table linkage. */ 754 struct pid pids[PIDTYPE_MAX]; 755 struct list_head thread_group; 756 757 struct completion *vfork_done; /* for vfork() */ 758 int __user *set_child_tid; /* CLONE_CHILD_SETTID */ 759 int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */ 760 761 unsigned long rt_priority; 762 cputime_t utime, stime; 763 unsigned long nvcsw, nivcsw; /* context switch counts */ 764 struct timespec start_time; 765 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */ 766 unsigned long min_flt, maj_flt; 767 768 cputime_t it_prof_expires, it_virt_expires; 769 unsigned long long it_sched_expires; 770 struct list_head cpu_timers[3]; 771 772 /* process credentials */ 773 uid_t uid,euid,suid,fsuid; 774 gid_t gid,egid,sgid,fsgid; 775 struct group_info *group_info; 776 kernel_cap_t cap_effective, cap_inheritable, cap_permitted; 777 unsigned keep_capabilities:1; 778 struct user_struct *user; 779 #ifdef CONFIG_KEYS 780 struct key *request_key_auth; /* assumed request_key authority */ 781 struct key *thread_keyring; /* keyring private to this thread */ 782 unsigned char jit_keyring; /* default keyring to attach requested keys to */ 783 #endif 784 int oomkilladj; /* OOM kill score adjustment (bit shift). */ 785 char comm[TASK_COMM_LEN]; /* executable name excluding path 786 - access with [gs]et_task_comm (which lock 787 it with task_lock()) 788 - initialized normally by flush_old_exec */ 789 /* file system info */ 790 int link_count, total_link_count; 791 /* ipc stuff */ 792 struct sysv_sem sysvsem; 793 /* CPU-specific state of this task */ 794 struct thread_struct thread; 795 /* filesystem information */ 796 struct fs_struct *fs; 797 /* open file information */ 798 struct files_struct *files; 799 /* namespace */ 800 struct namespace *namespace; 801 /* signal handlers */ 802 struct signal_struct *signal; 803 struct sighand_struct *sighand; 804 805 sigset_t blocked, real_blocked; 806 sigset_t saved_sigmask; /* To be restored with TIF_RESTORE_SIGMASK */ 807 struct sigpending pending; 808 809 unsigned long sas_ss_sp; 810 size_t sas_ss_size; 811 int (*notifier)(void *priv); 812 void *notifier_data; 813 sigset_t *notifier_mask; 814 815 void *security; 816 struct audit_context *audit_context; 817 seccomp_t seccomp; 818 819 /* Thread group tracking */ 820 u32 parent_exec_id; 821 u32 self_exec_id; 822 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings */ 823 spinlock_t alloc_lock; 824 /* Protection of proc_dentry: nesting proc_lock, dcache_lock, write_lock_irq(&tasklist_lock); */ 825 spinlock_t proc_lock; 826 827 #ifdef CONFIG_DEBUG_MUTEXES 828 /* mutex deadlock detection */ 829 struct mutex_waiter *blocked_on; 830 #endif 831 832 /* journalling filesystem info */ 833 void *journal_info; 834 835 /* VM state */ 836 struct reclaim_state *reclaim_state; 837 838 struct dentry *proc_dentry; 839 struct backing_dev_info *backing_dev_info; 840 841 struct io_context *io_context; 842 843 unsigned long ptrace_message; 844 siginfo_t *last_siginfo; /* For ptrace use. */ 845 /* 846 * current io wait handle: wait queue entry to use for io waits 847 * If this thread is processing aio, this points at the waitqueue 848 * inside the currently handled kiocb. It may be NULL (i.e. default 849 * to a stack based synchronous wait) if its doing sync IO. 850 */ 851 wait_queue_t *io_wait; 852 /* i/o counters(bytes read/written, #syscalls */ 853 u64 rchar, wchar, syscr, syscw; 854 #if defined(CONFIG_BSD_PROCESS_ACCT) 855 u64 acct_rss_mem1; /* accumulated rss usage */ 856 u64 acct_vm_mem1; /* accumulated virtual memory usage */ 857 clock_t acct_stimexpd; /* clock_t-converted stime since last update */ 858 #endif 859 #ifdef CONFIG_NUMA 860 struct mempolicy *mempolicy; 861 short il_next; 862 #endif 863 #ifdef CONFIG_CPUSETS 864 struct cpuset *cpuset; 865 nodemask_t mems_allowed; 866 int cpuset_mems_generation; 867 int cpuset_mem_spread_rotor; 868 #endif 869 struct robust_list_head __user *robust_list; 870 #ifdef CONFIG_COMPAT 871 struct compat_robust_list_head __user *compat_robust_list; 872 #endif 873 874 atomic_t fs_excl; /* holding fs exclusive resources */ 875 struct rcu_head rcu; 876 }; 877 878 static inline pid_t process_group(struct task_struct *tsk) 879 { 880 return tsk->signal->pgrp; 881 } 882 883 /** 884 * pid_alive - check that a task structure is not stale 885 * @p: Task structure to be checked. 886 * 887 * Test if a process is not yet dead (at most zombie state) 888 * If pid_alive fails, then pointers within the task structure 889 * can be stale and must not be dereferenced. 890 */ 891 static inline int pid_alive(struct task_struct *p) 892 { 893 return p->pids[PIDTYPE_PID].nr != 0; 894 } 895 896 extern void free_task(struct task_struct *tsk); 897 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0) 898 899 extern void __put_task_struct_cb(struct rcu_head *rhp); 900 901 static inline void put_task_struct(struct task_struct *t) 902 { 903 if (atomic_dec_and_test(&t->usage)) 904 call_rcu(&t->rcu, __put_task_struct_cb); 905 } 906 907 /* 908 * Per process flags 909 */ 910 #define PF_ALIGNWARN 0x00000001 /* Print alignment warning msgs */ 911 /* Not implemented yet, only for 486*/ 912 #define PF_STARTING 0x00000002 /* being created */ 913 #define PF_EXITING 0x00000004 /* getting shut down */ 914 #define PF_DEAD 0x00000008 /* Dead */ 915 #define PF_FORKNOEXEC 0x00000040 /* forked but didn't exec */ 916 #define PF_SUPERPRIV 0x00000100 /* used super-user privileges */ 917 #define PF_DUMPCORE 0x00000200 /* dumped core */ 918 #define PF_SIGNALED 0x00000400 /* killed by a signal */ 919 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 920 #define PF_FLUSHER 0x00001000 /* responsible for disk writeback */ 921 #define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */ 922 #define PF_FREEZE 0x00004000 /* this task is being frozen for suspend now */ 923 #define PF_NOFREEZE 0x00008000 /* this thread should not be frozen */ 924 #define PF_FROZEN 0x00010000 /* frozen for system suspend */ 925 #define PF_FSTRANS 0x00020000 /* inside a filesystem transaction */ 926 #define PF_KSWAPD 0x00040000 /* I am kswapd */ 927 #define PF_SWAPOFF 0x00080000 /* I am in swapoff */ 928 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */ 929 #define PF_SYNCWRITE 0x00200000 /* I am doing a sync write */ 930 #define PF_BORROWED_MM 0x00400000 /* I am a kthread doing use_mm */ 931 #define PF_RANDOMIZE 0x00800000 /* randomize virtual address space */ 932 #define PF_SWAPWRITE 0x01000000 /* Allowed to write to swap */ 933 #define PF_SPREAD_PAGE 0x04000000 /* Spread page cache over cpuset */ 934 #define PF_SPREAD_SLAB 0x08000000 /* Spread some slab caches over cpuset */ 935 #define PF_MEMPOLICY 0x10000000 /* Non-default NUMA mempolicy */ 936 937 /* 938 * Only the _current_ task can read/write to tsk->flags, but other 939 * tasks can access tsk->flags in readonly mode for example 940 * with tsk_used_math (like during threaded core dumping). 941 * There is however an exception to this rule during ptrace 942 * or during fork: the ptracer task is allowed to write to the 943 * child->flags of its traced child (same goes for fork, the parent 944 * can write to the child->flags), because we're guaranteed the 945 * child is not running and in turn not changing child->flags 946 * at the same time the parent does it. 947 */ 948 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 949 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 950 #define clear_used_math() clear_stopped_child_used_math(current) 951 #define set_used_math() set_stopped_child_used_math(current) 952 #define conditional_stopped_child_used_math(condition, child) \ 953 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 954 #define conditional_used_math(condition) \ 955 conditional_stopped_child_used_math(condition, current) 956 #define copy_to_stopped_child_used_math(child) \ 957 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 958 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 959 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 960 #define used_math() tsk_used_math(current) 961 962 #ifdef CONFIG_SMP 963 extern int set_cpus_allowed(task_t *p, cpumask_t new_mask); 964 #else 965 static inline int set_cpus_allowed(task_t *p, cpumask_t new_mask) 966 { 967 if (!cpu_isset(0, new_mask)) 968 return -EINVAL; 969 return 0; 970 } 971 #endif 972 973 extern unsigned long long sched_clock(void); 974 extern unsigned long long current_sched_time(const task_t *current_task); 975 976 /* sched_exec is called by processes performing an exec */ 977 #ifdef CONFIG_SMP 978 extern void sched_exec(void); 979 #else 980 #define sched_exec() {} 981 #endif 982 983 #ifdef CONFIG_HOTPLUG_CPU 984 extern void idle_task_exit(void); 985 #else 986 static inline void idle_task_exit(void) {} 987 #endif 988 989 extern void sched_idle_next(void); 990 extern void set_user_nice(task_t *p, long nice); 991 extern int task_prio(const task_t *p); 992 extern int task_nice(const task_t *p); 993 extern int can_nice(const task_t *p, const int nice); 994 extern int task_curr(const task_t *p); 995 extern int idle_cpu(int cpu); 996 extern int sched_setscheduler(struct task_struct *, int, struct sched_param *); 997 extern task_t *idle_task(int cpu); 998 extern task_t *curr_task(int cpu); 999 extern void set_curr_task(int cpu, task_t *p); 1000 1001 void yield(void); 1002 1003 /* 1004 * The default (Linux) execution domain. 1005 */ 1006 extern struct exec_domain default_exec_domain; 1007 1008 union thread_union { 1009 struct thread_info thread_info; 1010 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1011 }; 1012 1013 #ifndef __HAVE_ARCH_KSTACK_END 1014 static inline int kstack_end(void *addr) 1015 { 1016 /* Reliable end of stack detection: 1017 * Some APM bios versions misalign the stack 1018 */ 1019 return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*))); 1020 } 1021 #endif 1022 1023 extern union thread_union init_thread_union; 1024 extern struct task_struct init_task; 1025 1026 extern struct mm_struct init_mm; 1027 1028 #define find_task_by_pid(nr) find_task_by_pid_type(PIDTYPE_PID, nr) 1029 extern struct task_struct *find_task_by_pid_type(int type, int pid); 1030 extern void set_special_pids(pid_t session, pid_t pgrp); 1031 extern void __set_special_pids(pid_t session, pid_t pgrp); 1032 1033 /* per-UID process charging. */ 1034 extern struct user_struct * alloc_uid(uid_t); 1035 static inline struct user_struct *get_uid(struct user_struct *u) 1036 { 1037 atomic_inc(&u->__count); 1038 return u; 1039 } 1040 extern void free_uid(struct user_struct *); 1041 extern void switch_uid(struct user_struct *); 1042 1043 #include <asm/current.h> 1044 1045 extern void do_timer(struct pt_regs *); 1046 1047 extern int FASTCALL(wake_up_state(struct task_struct * tsk, unsigned int state)); 1048 extern int FASTCALL(wake_up_process(struct task_struct * tsk)); 1049 extern void FASTCALL(wake_up_new_task(struct task_struct * tsk, 1050 unsigned long clone_flags)); 1051 #ifdef CONFIG_SMP 1052 extern void kick_process(struct task_struct *tsk); 1053 #else 1054 static inline void kick_process(struct task_struct *tsk) { } 1055 #endif 1056 extern void FASTCALL(sched_fork(task_t * p, int clone_flags)); 1057 extern void FASTCALL(sched_exit(task_t * p)); 1058 1059 extern int in_group_p(gid_t); 1060 extern int in_egroup_p(gid_t); 1061 1062 extern void proc_caches_init(void); 1063 extern void flush_signals(struct task_struct *); 1064 extern void flush_signal_handlers(struct task_struct *, int force_default); 1065 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info); 1066 1067 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) 1068 { 1069 unsigned long flags; 1070 int ret; 1071 1072 spin_lock_irqsave(&tsk->sighand->siglock, flags); 1073 ret = dequeue_signal(tsk, mask, info); 1074 spin_unlock_irqrestore(&tsk->sighand->siglock, flags); 1075 1076 return ret; 1077 } 1078 1079 extern void block_all_signals(int (*notifier)(void *priv), void *priv, 1080 sigset_t *mask); 1081 extern void unblock_all_signals(void); 1082 extern void release_task(struct task_struct * p); 1083 extern int send_sig_info(int, struct siginfo *, struct task_struct *); 1084 extern int send_group_sig_info(int, struct siginfo *, struct task_struct *); 1085 extern int force_sigsegv(int, struct task_struct *); 1086 extern int force_sig_info(int, struct siginfo *, struct task_struct *); 1087 extern int __kill_pg_info(int sig, struct siginfo *info, pid_t pgrp); 1088 extern int kill_pg_info(int, struct siginfo *, pid_t); 1089 extern int kill_proc_info(int, struct siginfo *, pid_t); 1090 extern int kill_proc_info_as_uid(int, struct siginfo *, pid_t, uid_t, uid_t); 1091 extern void do_notify_parent(struct task_struct *, int); 1092 extern void force_sig(int, struct task_struct *); 1093 extern void force_sig_specific(int, struct task_struct *); 1094 extern int send_sig(int, struct task_struct *, int); 1095 extern void zap_other_threads(struct task_struct *p); 1096 extern int kill_pg(pid_t, int, int); 1097 extern int kill_proc(pid_t, int, int); 1098 extern struct sigqueue *sigqueue_alloc(void); 1099 extern void sigqueue_free(struct sigqueue *); 1100 extern int send_sigqueue(int, struct sigqueue *, struct task_struct *); 1101 extern int send_group_sigqueue(int, struct sigqueue *, struct task_struct *); 1102 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *); 1103 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long); 1104 1105 /* These can be the second arg to send_sig_info/send_group_sig_info. */ 1106 #define SEND_SIG_NOINFO ((struct siginfo *) 0) 1107 #define SEND_SIG_PRIV ((struct siginfo *) 1) 1108 #define SEND_SIG_FORCED ((struct siginfo *) 2) 1109 1110 static inline int is_si_special(const struct siginfo *info) 1111 { 1112 return info <= SEND_SIG_FORCED; 1113 } 1114 1115 /* True if we are on the alternate signal stack. */ 1116 1117 static inline int on_sig_stack(unsigned long sp) 1118 { 1119 return (sp - current->sas_ss_sp < current->sas_ss_size); 1120 } 1121 1122 static inline int sas_ss_flags(unsigned long sp) 1123 { 1124 return (current->sas_ss_size == 0 ? SS_DISABLE 1125 : on_sig_stack(sp) ? SS_ONSTACK : 0); 1126 } 1127 1128 /* 1129 * Routines for handling mm_structs 1130 */ 1131 extern struct mm_struct * mm_alloc(void); 1132 1133 /* mmdrop drops the mm and the page tables */ 1134 extern void FASTCALL(__mmdrop(struct mm_struct *)); 1135 static inline void mmdrop(struct mm_struct * mm) 1136 { 1137 if (atomic_dec_and_test(&mm->mm_count)) 1138 __mmdrop(mm); 1139 } 1140 1141 /* mmput gets rid of the mappings and all user-space */ 1142 extern void mmput(struct mm_struct *); 1143 /* Grab a reference to a task's mm, if it is not already going away */ 1144 extern struct mm_struct *get_task_mm(struct task_struct *task); 1145 /* Remove the current tasks stale references to the old mm_struct */ 1146 extern void mm_release(struct task_struct *, struct mm_struct *); 1147 1148 extern int copy_thread(int, unsigned long, unsigned long, unsigned long, struct task_struct *, struct pt_regs *); 1149 extern void flush_thread(void); 1150 extern void exit_thread(void); 1151 1152 extern void exit_files(struct task_struct *); 1153 extern void __cleanup_signal(struct signal_struct *); 1154 extern void __cleanup_sighand(struct sighand_struct *); 1155 extern void exit_itimers(struct signal_struct *); 1156 1157 extern NORET_TYPE void do_group_exit(int); 1158 1159 extern void daemonize(const char *, ...); 1160 extern int allow_signal(int); 1161 extern int disallow_signal(int); 1162 extern task_t *child_reaper; 1163 1164 extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *); 1165 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *); 1166 task_t *fork_idle(int); 1167 1168 extern void set_task_comm(struct task_struct *tsk, char *from); 1169 extern void get_task_comm(char *to, struct task_struct *tsk); 1170 1171 #ifdef CONFIG_SMP 1172 extern void wait_task_inactive(task_t * p); 1173 #else 1174 #define wait_task_inactive(p) do { } while (0) 1175 #endif 1176 1177 #define remove_parent(p) list_del_init(&(p)->sibling) 1178 #define add_parent(p) list_add_tail(&(p)->sibling,&(p)->parent->children) 1179 1180 #define next_task(p) list_entry((p)->tasks.next, struct task_struct, tasks) 1181 #define prev_task(p) list_entry((p)->tasks.prev, struct task_struct, tasks) 1182 1183 #define for_each_process(p) \ 1184 for (p = &init_task ; (p = next_task(p)) != &init_task ; ) 1185 1186 /* 1187 * Careful: do_each_thread/while_each_thread is a double loop so 1188 * 'break' will not work as expected - use goto instead. 1189 */ 1190 #define do_each_thread(g, t) \ 1191 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do 1192 1193 #define while_each_thread(g, t) \ 1194 while ((t = next_thread(t)) != g) 1195 1196 #define thread_group_leader(p) (p->pid == p->tgid) 1197 1198 static inline task_t *next_thread(task_t *p) 1199 { 1200 return list_entry(rcu_dereference(p->thread_group.next), 1201 task_t, thread_group); 1202 } 1203 1204 static inline int thread_group_empty(task_t *p) 1205 { 1206 return list_empty(&p->thread_group); 1207 } 1208 1209 #define delay_group_leader(p) \ 1210 (thread_group_leader(p) && !thread_group_empty(p)) 1211 1212 /* 1213 * Protects ->fs, ->files, ->mm, ->ptrace, ->group_info, ->comm, keyring 1214 * subscriptions and synchronises with wait4(). Also used in procfs. Also 1215 * pins the final release of task.io_context. Also protects ->cpuset. 1216 * 1217 * Nests both inside and outside of read_lock(&tasklist_lock). 1218 * It must not be nested with write_lock_irq(&tasklist_lock), 1219 * neither inside nor outside. 1220 */ 1221 static inline void task_lock(struct task_struct *p) 1222 { 1223 spin_lock(&p->alloc_lock); 1224 } 1225 1226 static inline void task_unlock(struct task_struct *p) 1227 { 1228 spin_unlock(&p->alloc_lock); 1229 } 1230 1231 extern struct sighand_struct *lock_task_sighand(struct task_struct *tsk, 1232 unsigned long *flags); 1233 1234 static inline void unlock_task_sighand(struct task_struct *tsk, 1235 unsigned long *flags) 1236 { 1237 spin_unlock_irqrestore(&tsk->sighand->siglock, *flags); 1238 } 1239 1240 #ifndef __HAVE_THREAD_FUNCTIONS 1241 1242 #define task_thread_info(task) (task)->thread_info 1243 #define task_stack_page(task) ((void*)((task)->thread_info)) 1244 1245 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org) 1246 { 1247 *task_thread_info(p) = *task_thread_info(org); 1248 task_thread_info(p)->task = p; 1249 } 1250 1251 static inline unsigned long *end_of_stack(struct task_struct *p) 1252 { 1253 return (unsigned long *)(p->thread_info + 1); 1254 } 1255 1256 #endif 1257 1258 /* set thread flags in other task's structures 1259 * - see asm/thread_info.h for TIF_xxxx flags available 1260 */ 1261 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 1262 { 1263 set_ti_thread_flag(task_thread_info(tsk), flag); 1264 } 1265 1266 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1267 { 1268 clear_ti_thread_flag(task_thread_info(tsk), flag); 1269 } 1270 1271 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 1272 { 1273 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 1274 } 1275 1276 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1277 { 1278 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 1279 } 1280 1281 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 1282 { 1283 return test_ti_thread_flag(task_thread_info(tsk), flag); 1284 } 1285 1286 static inline void set_tsk_need_resched(struct task_struct *tsk) 1287 { 1288 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1289 } 1290 1291 static inline void clear_tsk_need_resched(struct task_struct *tsk) 1292 { 1293 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1294 } 1295 1296 static inline int signal_pending(struct task_struct *p) 1297 { 1298 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING)); 1299 } 1300 1301 static inline int need_resched(void) 1302 { 1303 return unlikely(test_thread_flag(TIF_NEED_RESCHED)); 1304 } 1305 1306 /* 1307 * cond_resched() and cond_resched_lock(): latency reduction via 1308 * explicit rescheduling in places that are safe. The return 1309 * value indicates whether a reschedule was done in fact. 1310 * cond_resched_lock() will drop the spinlock before scheduling, 1311 * cond_resched_softirq() will enable bhs before scheduling. 1312 */ 1313 extern int cond_resched(void); 1314 extern int cond_resched_lock(spinlock_t * lock); 1315 extern int cond_resched_softirq(void); 1316 1317 /* 1318 * Does a critical section need to be broken due to another 1319 * task waiting?: 1320 */ 1321 #if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP) 1322 # define need_lockbreak(lock) ((lock)->break_lock) 1323 #else 1324 # define need_lockbreak(lock) 0 1325 #endif 1326 1327 /* 1328 * Does a critical section need to be broken due to another 1329 * task waiting or preemption being signalled: 1330 */ 1331 static inline int lock_need_resched(spinlock_t *lock) 1332 { 1333 if (need_lockbreak(lock) || need_resched()) 1334 return 1; 1335 return 0; 1336 } 1337 1338 /* Reevaluate whether the task has signals pending delivery. 1339 This is required every time the blocked sigset_t changes. 1340 callers must hold sighand->siglock. */ 1341 1342 extern FASTCALL(void recalc_sigpending_tsk(struct task_struct *t)); 1343 extern void recalc_sigpending(void); 1344 1345 extern void signal_wake_up(struct task_struct *t, int resume_stopped); 1346 1347 /* 1348 * Wrappers for p->thread_info->cpu access. No-op on UP. 1349 */ 1350 #ifdef CONFIG_SMP 1351 1352 static inline unsigned int task_cpu(const struct task_struct *p) 1353 { 1354 return task_thread_info(p)->cpu; 1355 } 1356 1357 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 1358 { 1359 task_thread_info(p)->cpu = cpu; 1360 } 1361 1362 #else 1363 1364 static inline unsigned int task_cpu(const struct task_struct *p) 1365 { 1366 return 0; 1367 } 1368 1369 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 1370 { 1371 } 1372 1373 #endif /* CONFIG_SMP */ 1374 1375 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT 1376 extern void arch_pick_mmap_layout(struct mm_struct *mm); 1377 #else 1378 static inline void arch_pick_mmap_layout(struct mm_struct *mm) 1379 { 1380 mm->mmap_base = TASK_UNMAPPED_BASE; 1381 mm->get_unmapped_area = arch_get_unmapped_area; 1382 mm->unmap_area = arch_unmap_area; 1383 } 1384 #endif 1385 1386 extern long sched_setaffinity(pid_t pid, cpumask_t new_mask); 1387 extern long sched_getaffinity(pid_t pid, cpumask_t *mask); 1388 1389 extern void normalize_rt_tasks(void); 1390 1391 #ifdef CONFIG_PM 1392 /* 1393 * Check if a process has been frozen 1394 */ 1395 static inline int frozen(struct task_struct *p) 1396 { 1397 return p->flags & PF_FROZEN; 1398 } 1399 1400 /* 1401 * Check if there is a request to freeze a process 1402 */ 1403 static inline int freezing(struct task_struct *p) 1404 { 1405 return p->flags & PF_FREEZE; 1406 } 1407 1408 /* 1409 * Request that a process be frozen 1410 * FIXME: SMP problem. We may not modify other process' flags! 1411 */ 1412 static inline void freeze(struct task_struct *p) 1413 { 1414 p->flags |= PF_FREEZE; 1415 } 1416 1417 /* 1418 * Wake up a frozen process 1419 */ 1420 static inline int thaw_process(struct task_struct *p) 1421 { 1422 if (frozen(p)) { 1423 p->flags &= ~PF_FROZEN; 1424 wake_up_process(p); 1425 return 1; 1426 } 1427 return 0; 1428 } 1429 1430 /* 1431 * freezing is complete, mark process as frozen 1432 */ 1433 static inline void frozen_process(struct task_struct *p) 1434 { 1435 p->flags = (p->flags & ~PF_FREEZE) | PF_FROZEN; 1436 } 1437 1438 extern void refrigerator(void); 1439 extern int freeze_processes(void); 1440 extern void thaw_processes(void); 1441 1442 static inline int try_to_freeze(void) 1443 { 1444 if (freezing(current)) { 1445 refrigerator(); 1446 return 1; 1447 } else 1448 return 0; 1449 } 1450 #else 1451 static inline int frozen(struct task_struct *p) { return 0; } 1452 static inline int freezing(struct task_struct *p) { return 0; } 1453 static inline void freeze(struct task_struct *p) { BUG(); } 1454 static inline int thaw_process(struct task_struct *p) { return 1; } 1455 static inline void frozen_process(struct task_struct *p) { BUG(); } 1456 1457 static inline void refrigerator(void) {} 1458 static inline int freeze_processes(void) { BUG(); return 0; } 1459 static inline void thaw_processes(void) {} 1460 1461 static inline int try_to_freeze(void) { return 0; } 1462 1463 #endif /* CONFIG_PM */ 1464 #endif /* __KERNEL__ */ 1465 1466 #endif 1467