include/linux/sched.h

   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
  16 #include <asm/system.h>
  17 #include <asm/semaphore.h>
  18 #include <asm/page.h>
  19 #include <asm/ptrace.h>
  20 #include <asm/mmu.h>
  21
  22 #include <linux/smp.h>
  23 #include <linux/sem.h>
  24 #include <linux/signal.h>
  25 #include <linux/securebits.h>
  26 #include <linux/fs_struct.h>
  27 #include <linux/compiler.h>
  28 #include <linux/completion.h>
  29 #include <linux/pid.h>
  30 #include <linux/percpu.h>
  31
  32 struct exec_domain;
  33
  34 /*
  35  * cloning flags:
  36  */
  37 #define CSIGNAL         0x000000ff      /* signal mask to be sent at exit */
  38 #define CLONE_VM        0x00000100      /* set if VM shared between processes */
  39 #define CLONE_FS        0x00000200      /* set if fs info shared between processes */
  40 #define CLONE_FILES     0x00000400      /* set if open files shared between processes */
  41 #define CLONE_SIGHAND   0x00000800      /* set if signal handlers and blocked signals shared */
  42 #define CLONE_IDLETASK  0x00001000      /* set if new pid should be 0 (kernel only)*/
  43 #define CLONE_PTRACE    0x00002000      /* set if we want to let tracing continue on the child too */
  44 #define CLONE_VFORK     0x00004000      /* set if the parent wants the child to wake it up on mm_release */
  45 #define CLONE_PARENT    0x00008000      /* set if we want to have the same parent as the cloner */
  46 #define CLONE_THREAD    0x00010000      /* Same thread group? */
  47 #define CLONE_NEWNS     0x00020000      /* New namespace group? */
  48 #define CLONE_SYSVSEM   0x00040000      /* share system V SEM_UNDO semantics */
  49 #define CLONE_SETTLS    0x00080000      /* create a new TLS for the child */
  50 #define CLONE_PARENT_SETTID     0x00100000      /* set the TID in the parent */
  51 #define CLONE_CHILD_CLEARTID    0x00200000      /* clear the TID in the child */
  52 #define CLONE_DETACHED          0x00400000      /* parent wants no child-exit signal */
  53 #define CLONE_UNTRACED          0x00800000      /* set if the tracing process can't force CLONE_PTRACE on this clone */
  54 #define CLONE_CHILD_SETTID      0x01000000      /* set the TID in the child */
  55
  56 /*
  57  * List of flags we want to share for kernel threads,
  58  * if only because they are not used by them anyway.
  59  */
  60 #define CLONE_KERNEL    (CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
  61
  62 /*
  63  * These are the constant used to fake the fixed-point load-average
  64  * counting. Some notes:
  65  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
  66  *    a load-average precision of 10 bits integer + 11 bits fractional
  67  *  - if you want to count load-averages more often, you need more
  68  *    precision, or rounding will get you. With 2-second counting freq,
  69  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
  70  *    11 bit fractions.
  71  */
  72 extern unsigned long avenrun[];         /* Load averages */
  73
  74 #define FSHIFT          11              /* nr of bits of precision */
  75 #define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
  76 #define LOAD_FREQ       (5*HZ)          /* 5 sec intervals */
  77 #define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
  78 #define EXP_5           2014            /* 1/exp(5sec/5min) */
  79 #define EXP_15          2037            /* 1/exp(5sec/15min) */
  80
  81 #define CALC_LOAD(load,exp,n) \
  82         load *= exp; \
  83         load += n*(FIXED_1-exp); \
  84         load >>= FSHIFT;
  85
  86 #define CT_TO_SECS(x)   ((x) / HZ)
  87 #define CT_TO_USECS(x)  (((x) % HZ) * 1000000/HZ)
  88
  89 extern int nr_threads;
  90 extern int last_pid;
  91 DECLARE_PER_CPU(unsigned long, process_counts);
  92 extern int nr_processes(void);
  93 extern unsigned long nr_running(void);
  94 extern unsigned long nr_uninterruptible(void);
  95 extern unsigned long nr_iowait(void);
  96
  97 #include <linux/time.h>
  98 #include <linux/param.h>
  99 #include <linux/resource.h>
 100 #include <linux/timer.h>
 101
 102 #include <asm/processor.h>
 103
 104 #define TASK_RUNNING            0
 105 #define TASK_INTERRUPTIBLE      1
 106 #define TASK_UNINTERRUPTIBLE    2
 107 #define TASK_STOPPED            4
 108 #define TASK_ZOMBIE             8
 109 #define TASK_DEAD               16
 110
 111 #define __set_task_state(tsk, state_value)              \
 112         do { (tsk)->state = (state_value); } while (0)
 113 #define set_task_state(tsk, state_value)                \
 114         set_mb((tsk)->state, (state_value))
 115
 116 #define __set_current_state(state_value)                        \
 117         do { current->state = (state_value); } while (0)
 118 #define set_current_state(state_value)          \
 119         set_mb(current->state, (state_value))
 120
 121 /*
 122  * Scheduling policies
 123  */
 124 #define SCHED_NORMAL            0
 125 #define SCHED_FIFO              1
 126 #define SCHED_RR                2
 127
 128 struct sched_param {
 129         int sched_priority;
 130 };
 131
 132 #ifdef __KERNEL__
 133
 134 #include <linux/spinlock.h>
 135
 136 /*
 137  * This serializes "schedule()" and also protects
 138  * the run-queue from deletions/modifications (but
 139  * _adding_ to the beginning of the run-queue has
 140  * a separate lock).
 141  */
 142 extern rwlock_t tasklist_lock;
 143 extern spinlock_t mmlist_lock;
 144
 145 typedef struct task_struct task_t;
 146
 147 extern void sched_init(void);
 148 extern void init_idle(task_t *idle, int cpu);
 149
 150 extern void show_state(void);
 151 extern void show_trace(unsigned long *stack);
 152 extern void show_stack(unsigned long *stack);
 153 extern void show_regs(struct pt_regs *);
 154
 155 void io_schedule(void);
 156 long io_schedule_timeout(long timeout);
 157
 158 extern void cpu_init (void);
 159 extern void trap_init(void);
 160 extern void update_process_times(int user);
 161 extern void update_one_process(struct task_struct *p, unsigned long user,
 162                                unsigned long system, int cpu);
 163 extern void scheduler_tick(int user_tick, int system);
 164 extern unsigned long cache_decay_ticks;
 165
 166
 167 #define MAX_SCHEDULE_TIMEOUT    LONG_MAX
 168 extern signed long FASTCALL(schedule_timeout(signed long timeout));
 169 asmlinkage void schedule(void);
 170
 171 struct namespace;
 172
 173 /* Maximum number of active map areas.. This is a random (large) number */
 174 #define MAX_MAP_COUNT   (65536)
 175
 176 #include <linux/aio.h>
 177
 178 struct mm_struct {
 179         struct vm_area_struct * mmap;           /* list of VMAs */
 180         struct rb_root mm_rb;
 181         struct vm_area_struct * mmap_cache;     /* last find_vma result */
 182         unsigned long free_area_cache;          /* first hole */
 183         pgd_t * pgd;
 184         atomic_t mm_users;                      /* How many users with user space? */
 185         atomic_t mm_count;                      /* How many references to "struct mm_struct" (users count as 1) */
 186         int map_count;                          /* number of VMAs */
 187         struct rw_semaphore mmap_sem;
 188         spinlock_t page_table_lock;             /* Protects task page tables and mm->rss */
 189
 190         struct list_head mmlist;                /* List of all active mm's.  These are globally strung
 191                                                  * together off init_mm.mmlist, and are protected
 192                                                  * by mmlist_lock
 193                                                  */
 194
 195         unsigned long start_code, end_code, start_data, end_data;
 196         unsigned long start_brk, brk, start_stack;
 197         unsigned long arg_start, arg_end, env_start, env_end;
 198         unsigned long rss, total_vm, locked_vm;
 199         unsigned long def_flags;
 200         unsigned long cpu_vm_mask;
 201         unsigned long swap_address;
 202
 203         unsigned dumpable:1;
 204
 205         /* Architecture-specific MM context */
 206         mm_context_t context;
 207
 208         /* coredumping support */
 209         int core_waiters;
 210         struct completion *core_startup_done, core_done;
 211
 212         /* aio bits */
 213         rwlock_t                ioctx_list_lock;
 214         struct kioctx           *ioctx_list;
 215
 216         struct kioctx           default_kioctx;
 217 };
 218
 219 extern int mmlist_nr;
 220
 221 struct signal_struct {
 222         atomic_t                count;
 223         struct k_sigaction      action[_NSIG];
 224         spinlock_t              siglock;
 225
 226         /* current thread group signal load-balancing target: */
 227         task_t                  *curr_target;
 228
 229         /* shared signal handling: */
 230         struct sigpending       shared_pending;
 231
 232         /* thread group exit support */
 233         int                     group_exit;
 234         int                     group_exit_code;
 235         struct task_struct      *group_exit_task;
 236 };
 237
 238 /*
 239  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
 240  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL tasks are
 241  * in the range MAX_RT_PRIO..MAX_PRIO-1. Priority values
 242  * are inverted: lower p->prio value means higher priority.
 243  *
 244  * The MAX_RT_USER_PRIO value allows the actual maximum
 245  * RT priority to be separate from the value exported to
 246  * user-space.  This allows kernel threads to set their
 247  * priority to a value higher than any user task. Note:
 248  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
 249  */
 250
 251 #define MAX_USER_RT_PRIO        100
 252 #define MAX_RT_PRIO             MAX_USER_RT_PRIO
 253
 254 #define MAX_PRIO                (MAX_RT_PRIO + 40)
 255
 256 /*
 257  * Some day this will be a full-fledged user tracking system..
 258  */
 259 struct user_struct {
 260         atomic_t __count;       /* reference count */
 261         atomic_t processes;     /* How many processes does this user have? */
 262         atomic_t files;         /* How many open files does this user have? */
 263
 264         /* Hash table maintenance information */
 265         struct list_head uidhash_list;
 266         uid_t uid;
 267 };
 268
 269 #define get_current_user() ({                           \
 270         struct user_struct *__user = current->user;     \
 271         atomic_inc(&__user->__count);                   \
 272         __user; })
 273
 274 extern struct user_struct *find_user(uid_t);
 275
 276 extern struct user_struct root_user;
 277 #define INIT_USER (&root_user)
 278
 279 typedef struct prio_array prio_array_t;
 280 struct backing_dev_info;
 281
 282 struct task_struct {
 283         volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
 284         struct thread_info *thread_info;
 285         atomic_t usage;
 286         unsigned long flags;    /* per process flags, defined below */
 287         unsigned long ptrace;
 288
 289         int lock_depth;         /* Lock depth */
 290
 291         int prio, static_prio;
 292         struct list_head run_list;
 293         prio_array_t *array;
 294
 295         unsigned long sleep_avg;
 296         unsigned long sleep_timestamp;
 297
 298         unsigned long policy;
 299         unsigned long cpus_allowed;
 300         unsigned int time_slice, first_time_slice;
 301
 302         struct list_head tasks;
 303         struct list_head ptrace_children;
 304         struct list_head ptrace_list;
 305
 306         struct mm_struct *mm, *active_mm;
 307
 308 /* task state */
 309         struct linux_binfmt *binfmt;
 310         int exit_code, exit_signal;
 311         int pdeath_signal;  /*  The signal sent when the parent dies  */
 312         /* ??? */
 313         unsigned long personality;
 314         int did_exec:1;
 315         pid_t pid;
 316         pid_t pgrp;
 317         pid_t tty_old_pgrp;
 318         pid_t session;
 319         pid_t tgid;
 320         /* boolean value for session group leader */
 321         int leader;
 322         /*
 323          * pointers to (original) parent process, youngest child, younger sibling,
 324          * older sibling, respectively.  (p->father can be replaced with
 325          * p->parent->pid)
 326          */
 327         struct task_struct *real_parent; /* real parent process (when being debugged) */
 328         struct task_struct *parent;     /* parent process */
 329         struct list_head children;      /* list of my children */
 330         struct list_head sibling;       /* linkage in my parent's children list */
 331         struct task_struct *group_leader;
 332
 333         /* PID/PID hash table linkage. */
 334         struct pid_link pids[PIDTYPE_MAX];
 335
 336         wait_queue_head_t wait_chldexit;        /* for wait4() */
 337         struct completion *vfork_done;          /* for vfork() */
 338         int *set_child_tid;                     /* CLONE_CHILD_SETTID */
 339         int *clear_child_tid;                   /* CLONE_CHILD_CLEARTID */
 340
 341         unsigned long rt_priority;
 342         unsigned long it_real_value, it_prof_value, it_virt_value;
 343         unsigned long it_real_incr, it_prof_incr, it_virt_incr;
 344         struct timer_list real_timer;
 345         unsigned long utime, stime, cutime, cstime;
 346         unsigned long start_time;
 347 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
 348         unsigned long min_flt, maj_flt, nswap, cmin_flt, cmaj_flt, cnswap;
 349 /* process credentials */
 350         uid_t uid,euid,suid,fsuid;
 351         gid_t gid,egid,sgid,fsgid;
 352         int ngroups;
 353         gid_t   groups[NGROUPS];
 354         kernel_cap_t   cap_effective, cap_inheritable, cap_permitted;
 355         int keep_capabilities:1;
 356         struct user_struct *user;
 357 /* limits */
 358         struct rlimit rlim[RLIM_NLIMITS];
 359         unsigned short used_math;
 360         char comm[16];
 361 /* file system info */
 362         int link_count, total_link_count;
 363         struct tty_struct *tty; /* NULL if no tty */
 364         unsigned int locks; /* How many file locks are being held */
 365 /* ipc stuff */
 366         struct sysv_sem sysvsem;
 367 /* CPU-specific state of this task */
 368         struct thread_struct thread;
 369 /* filesystem information */
 370         struct fs_struct *fs;
 371 /* open file information */
 372         struct files_struct *files;
 373 /* namespace */
 374         struct namespace *namespace;
 375 /* signal handlers */
 376         struct signal_struct *sig;
 377
 378         sigset_t blocked, real_blocked;
 379         struct sigpending pending;
 380
 381         unsigned long sas_ss_sp;
 382         size_t sas_ss_size;
 383         int (*notifier)(void *priv);
 384         void *notifier_data;
 385         sigset_t *notifier_mask;
 386
 387         void *security;
 388
 389 /* Thread group tracking */
 390         u32 parent_exec_id;
 391         u32 self_exec_id;
 392 /* Protection of (de-)allocation: mm, files, fs, tty */
 393         spinlock_t alloc_lock;
 394 /* context-switch lock */
 395         spinlock_t switch_lock;
 396
 397 /* journalling filesystem info */
 398         void *journal_info;
 399         struct dentry *proc_dentry;
 400         struct backing_dev_info *backing_dev_info;
 401
 402         unsigned long ptrace_message;
 403 };
 404
 405 extern void __put_task_struct(struct task_struct *tsk);
 406 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
 407 #define put_task_struct(tsk) \
 408 do { if (atomic_dec_and_test(&(tsk)->usage)) __put_task_struct(tsk); } while(0)
 409
 410 /*
 411  * Per process flags
 412  */
 413 #define PF_ALIGNWARN    0x00000001      /* Print alignment warning msgs */
 414                                         /* Not implemented yet, only for 486*/
 415 #define PF_STARTING     0x00000002      /* being created */
 416 #define PF_EXITING      0x00000004      /* getting shut down */
 417 #define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
 418 #define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
 419 #define PF_DUMPCORE     0x00000200      /* dumped core */
 420 #define PF_SIGNALED     0x00000400      /* killed by a signal */
 421 #define PF_MEMALLOC     0x00000800      /* Allocating memory */
 422 #define PF_MEMDIE       0x00001000      /* Killed for out-of-memory */
 423 #define PF_FLUSHER      0x00002000      /* responsible for disk writeback */
 424
 425 #define PF_FREEZE       0x00004000      /* this task should be frozen for suspend */
 426 #define PF_IOTHREAD     0x00008000      /* this thread is needed for doing I/O to swap */
 427 #define PF_FROZEN       0x00010000      /* frozen for system suspend */
 428 #define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
 429 #define PF_KSWAPD       0x00040000      /* I am kswapd */
 430
 431 /*
 432  * Ptrace flags
 433  */
 434
 435 #define PT_PTRACED      0x00000001
 436 #define PT_DTRACE       0x00000002      /* delayed trace (used on m68k, i386) */
 437 #define PT_TRACESYSGOOD 0x00000004
 438 #define PT_PTRACE_CAP   0x00000008      /* ptracer can follow suid-exec */
 439 #define PT_TRACE_FORK   0x00000010
 440 #define PT_TRACE_VFORK  0x00000020
 441 #define PT_TRACE_CLONE  0x00000040
 442 #define PT_TRACE_EXEC   0x00000080
 443
 444 #if CONFIG_SMP
 445 extern void set_cpus_allowed(task_t *p, unsigned long new_mask);
 446 #else
 447 # define set_cpus_allowed(p, new_mask) do { } while (0)
 448 #endif
 449
 450 #ifdef CONFIG_NUMA
 451 extern void sched_balance_exec(void);
 452 extern void node_nr_running_init(void);
 453 #else
 454 #define sched_balance_exec()   {}
 455 #define node_nr_running_init() {}
 456 #endif
 457
 458 extern void set_user_nice(task_t *p, long nice);
 459 extern int task_prio(task_t *p);
 460 extern int task_nice(task_t *p);
 461 extern int task_curr(task_t *p);
 462 extern int idle_cpu(int cpu);
 463
 464 void yield(void);
 465
 466 /*
 467  * The default (Linux) execution domain.
 468  */
 469 extern struct exec_domain       default_exec_domain;
 470
 471 #ifndef INIT_THREAD_SIZE
 472 # define INIT_THREAD_SIZE       2048*sizeof(long)
 473 #endif
 474
 475 union thread_union {
 476         struct thread_info thread_info;
 477         unsigned long stack[INIT_THREAD_SIZE/sizeof(long)];
 478 };
 479
 480 extern union thread_union init_thread_union;
 481 extern struct task_struct init_task;
 482
 483 extern struct   mm_struct init_mm;
 484
 485 extern struct task_struct *find_task_by_pid(int pid);
 486
 487 /* per-UID process charging. */
 488 extern struct user_struct * alloc_uid(uid_t);
 489 extern void free_uid(struct user_struct *);
 490
 491 #include <asm/current.h>
 492
 493 extern unsigned long itimer_ticks;
 494 extern unsigned long itimer_next;
 495 extern void do_timer(struct pt_regs *);
 496
 497 extern int FASTCALL(wake_up_process(struct task_struct * tsk));
 498 extern void FASTCALL(wake_up_forked_process(struct task_struct * tsk));
 499 extern void FASTCALL(sched_exit(task_t * p));
 500
 501 asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru);
 502
 503 extern int in_group_p(gid_t);
 504 extern int in_egroup_p(gid_t);
 505
 506 extern ATTRIB_NORET void cpu_idle(void);
 507
 508 extern void release_task(struct task_struct * p);
 509
 510 extern void proc_caches_init(void);
 511 extern void flush_signals(struct task_struct *);
 512 extern void flush_signal_handlers(struct task_struct *);
 513 extern void sig_exit(int, int, struct siginfo *);
 514 extern int dequeue_signal(sigset_t *mask, siginfo_t *info);
 515 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
 516                               sigset_t *mask);
 517 extern void unblock_all_signals(void);
 518 extern void release_task(struct task_struct * p);
 519 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
 520 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
 521 extern int __kill_pg_info(int sig, struct siginfo *info, pid_t pgrp);
 522 extern int kill_pg_info(int, struct siginfo *, pid_t);
 523 extern int kill_sl_info(int, struct siginfo *, pid_t);
 524 extern int kill_proc_info(int, struct siginfo *, pid_t);
 525 extern void notify_parent(struct task_struct *, int);
 526 extern void do_notify_parent(struct task_struct *, int);
 527 extern void force_sig(int, struct task_struct *);
 528 extern void force_sig_specific(int, struct task_struct *);
 529 extern int send_sig(int, struct task_struct *, int);
 530 extern int __broadcast_thread_group(struct task_struct *p, int sig);
 531 extern int kill_pg(pid_t, int, int);
 532 extern int kill_sl(pid_t, int, int);
 533 extern int kill_proc(pid_t, int, int);
 534 extern int do_sigaction(int, const struct k_sigaction *, struct k_sigaction *);
 535 extern int do_sigaltstack(const stack_t *, stack_t *, unsigned long);
 536
 537 /* True if we are on the alternate signal stack.  */
 538
 539 static inline int on_sig_stack(unsigned long sp)
 540 {
 541         return (sp - current->sas_ss_sp < current->sas_ss_size);
 542 }
 543
 544 static inline int sas_ss_flags(unsigned long sp)
 545 {
 546         return (current->sas_ss_size == 0 ? SS_DISABLE
 547                 : on_sig_stack(sp) ? SS_ONSTACK : 0);
 548 }
 549
 550
 551 #ifdef CONFIG_SECURITY
 552 /* code is in security.c */
 553 extern int capable(int cap);
 554 #else
 555 static inline int capable(int cap)
 556 {
 557         if (cap_raised(current->cap_effective, cap)) {
 558                 current->flags |= PF_SUPERPRIV;
 559                 return 1;
 560         }
 561         return 0;
 562 }
 563 #endif
 564
 565 /*
 566  * Routines for handling mm_structs
 567  */
 568 extern struct mm_struct * mm_alloc(void);
 569
 570 extern struct mm_struct * start_lazy_tlb(void);
 571 extern void end_lazy_tlb(struct mm_struct *mm);
 572
 573 /* mmdrop drops the mm and the page tables */
 574 extern inline void FASTCALL(__mmdrop(struct mm_struct *));
 575 static inline void mmdrop(struct mm_struct * mm)
 576 {
 577         if (atomic_dec_and_test(&mm->mm_count))
 578                 __mmdrop(mm);
 579 }
 580
 581 /* mmput gets rid of the mappings and all user-space */
 582 extern void mmput(struct mm_struct *);
 583 /* Remove the current tasks stale references to the old mm_struct */
 584 extern void mm_release(struct task_struct *, struct mm_struct *);
 585
 586 extern int  copy_thread(int, unsigned long, unsigned long, unsigned long, struct task_struct *, struct pt_regs *);
 587 extern void flush_thread(void);
 588 extern void exit_thread(void);
 589
 590 extern void exit_mm(struct task_struct *);
 591 extern void exit_files(struct task_struct *);
 592 extern void exit_sighand(struct task_struct *);
 593 extern void __exit_sighand(struct task_struct *);
 594
 595 extern void reparent_to_init(void);
 596 extern void daemonize(void);
 597 extern task_t *child_reaper;
 598
 599 extern int do_execve(char *, char **, char **, struct pt_regs *);
 600 extern struct task_struct *do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int *, int *);
 601
 602 #ifdef CONFIG_SMP
 603 extern void wait_task_inactive(task_t * p);
 604 #else
 605 #define wait_task_inactive(p)   do { } while (0)
 606 #endif
 607 extern void kick_if_running(task_t * p);
 608
 609 #define remove_parent(p)        list_del_init(&(p)->sibling)
 610 #define add_parent(p, parent)   list_add_tail(&(p)->sibling,&(parent)->children)
 611
 612 #define REMOVE_LINKS(p) do {                                    \
 613         if (thread_group_leader(p))                             \
 614                 list_del_init(&(p)->tasks);                     \
 615         remove_parent(p);                                       \
 616         } while (0)
 617
 618 #define SET_LINKS(p) do {                                       \
 619         if (thread_group_leader(p))                             \
 620                 list_add_tail(&(p)->tasks,&init_task.tasks);    \
 621         add_parent(p, (p)->parent);                             \
 622         } while (0)
 623
 624 #define next_task(p)    list_entry((p)->tasks.next, struct task_struct, tasks)
 625 #define prev_task(p)    list_entry((p)->tasks.prev, struct task_struct, tasks)
 626
 627 #define for_each_process(p) \
 628         for (p = &init_task ; (p = next_task(p)) != &init_task ; )
 629
 630 /*
 631  * Careful: do_each_thread/while_each_thread is a double loop so
 632  *          'break' will not work as expected - use goto instead.
 633  */
 634 #define do_each_thread(g, t) \
 635         for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
 636
 637 #define while_each_thread(g, t) \
 638         while ((t = next_thread(t)) != g)
 639
 640 extern task_t * FASTCALL(next_thread(task_t *p));
 641
 642 #define thread_group_leader(p)  (p->pid == p->tgid)
 643
 644 static inline int thread_group_empty(task_t *p)
 645 {
 646         struct pid *pid = p->pids[PIDTYPE_TGID].pidptr;
 647
 648         return pid->task_list.next->next == &pid->task_list;
 649 }
 650
 651 #define delay_group_leader(p) \
 652                 (thread_group_leader(p) && !thread_group_empty(p))
 653
 654 extern void unhash_process(struct task_struct *p);
 655
 656 /* Protects ->fs, ->files, ->mm, and synchronises with wait4().  Nests inside tasklist_lock */
 657 static inline void task_lock(struct task_struct *p)
 658 {
 659         spin_lock(&p->alloc_lock);
 660 }
 661
 662 static inline void task_unlock(struct task_struct *p)
 663 {
 664         spin_unlock(&p->alloc_lock);
 665 }
 666
 667 /**
 668  * get_task_mm - acquire a reference to the task's mm
 669  *
 670  * Returns %NULL if the task has no mm. User must release
 671  * the mm via mmput() after use.
 672  */
 673 static inline struct mm_struct * get_task_mm(struct task_struct * task)
 674 {
 675         struct mm_struct * mm;
 676
 677         task_lock(task);
 678         mm = task->mm;
 679         if (mm)
 680                 atomic_inc(&mm->mm_users);
 681         task_unlock(task);
 682
 683         return mm;
 684 }
 685
 686
 687 /* set thread flags in other task's structures
 688  * - see asm/thread_info.h for TIF_xxxx flags available
 689  */
 690 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
 691 {
 692         set_ti_thread_flag(tsk->thread_info,flag);
 693 }
 694
 695 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
 696 {
 697         clear_ti_thread_flag(tsk->thread_info,flag);
 698 }
 699
 700 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
 701 {
 702         return test_and_set_ti_thread_flag(tsk->thread_info,flag);
 703 }
 704
 705 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
 706 {
 707         return test_and_clear_ti_thread_flag(tsk->thread_info,flag);
 708 }
 709
 710 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
 711 {
 712         return test_ti_thread_flag(tsk->thread_info,flag);
 713 }
 714
 715 static inline void set_tsk_need_resched(struct task_struct *tsk)
 716 {
 717         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
 718 }
 719
 720 static inline void clear_tsk_need_resched(struct task_struct *tsk)
 721 {
 722         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
 723 }
 724
 725 static inline int signal_pending(struct task_struct *p)
 726 {
 727         return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
 728 }
 729
 730 static inline int need_resched(void)
 731 {
 732         return unlikely(test_thread_flag(TIF_NEED_RESCHED));
 733 }
 734
 735 extern void __cond_resched(void);
 736 static inline void cond_resched(void)
 737 {
 738         if (need_resched())
 739                 __cond_resched();
 740 }
 741
 742 /*
 743  * cond_resched_lock() - if a reschedule is pending, drop the given lock,
 744  * call schedule, and on return reacquire the lock.
 745  *
 746  * This works OK both with and without CONFIG_PREEMPT.  We do strange low-level
 747  * operations here to prevent schedule() from being called twice (once via
 748  * spin_unlock(), once by hand).
 749  */
 750 static inline void cond_resched_lock(spinlock_t * lock)
 751 {
 752         if (need_resched()) {
 753                 _raw_spin_unlock(lock);
 754                 preempt_enable_no_resched();
 755                 __cond_resched();
 756                 spin_lock(lock);
 757         }
 758 }
 759
 760 /* Reevaluate whether the task has signals pending delivery.
 761    This is required every time the blocked sigset_t changes.
 762    callers must hold sig->siglock.  */
 763
 764 extern FASTCALL(void recalc_sigpending_tsk(struct task_struct *t));
 765 extern void recalc_sigpending(void);
 766
 767 /*
 768  * Wrappers for p->thread_info->cpu access. No-op on UP.
 769  */
 770 #ifdef CONFIG_SMP
 771
 772 static inline unsigned int task_cpu(struct task_struct *p)
 773 {
 774         return p->thread_info->cpu;
 775 }
 776
 777 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
 778 {
 779         p->thread_info->cpu = cpu;
 780 }
 781
 782 #else
 783
 784 static inline unsigned int task_cpu(struct task_struct *p)
 785 {
 786         return 0;
 787 }
 788
 789 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
 790 {
 791 }
 792
 793 #endif /* CONFIG_SMP */
 794
 795 #endif /* __KERNEL__ */
 796
 797 #endif