~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/sched.h

Version: ~ [ linux-5.12-rc1 ] ~ [ linux-5.11.2 ] ~ [ linux-5.10.19 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.101 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.177 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.222 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.258 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.258 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /* SPDX-License-Identifier: GPL-2.0 */
  2 #ifndef _LINUX_SCHED_H
  3 #define _LINUX_SCHED_H
  4 
  5 /*
  6  * Define 'struct task_struct' and provide the main scheduler
  7  * APIs (schedule(), wakeup variants, etc.)
  8  */
  9 
 10 #include <uapi/linux/sched.h>
 11 
 12 #include <asm/current.h>
 13 
 14 #include <linux/pid.h>
 15 #include <linux/sem.h>
 16 #include <linux/shm.h>
 17 #include <linux/kcov.h>
 18 #include <linux/mutex.h>
 19 #include <linux/plist.h>
 20 #include <linux/hrtimer.h>
 21 #include <linux/seccomp.h>
 22 #include <linux/nodemask.h>
 23 #include <linux/rcupdate.h>
 24 #include <linux/resource.h>
 25 #include <linux/latencytop.h>
 26 #include <linux/sched/prio.h>
 27 #include <linux/signal_types.h>
 28 #include <linux/mm_types_task.h>
 29 #include <linux/task_io_accounting.h>
 30 
 31 /* task_struct member predeclarations (sorted alphabetically): */
 32 struct audit_context;
 33 struct backing_dev_info;
 34 struct bio_list;
 35 struct blk_plug;
 36 struct ccs_domain_info;
 37 struct cfs_rq;
 38 struct fs_struct;
 39 struct futex_pi_state;
 40 struct io_context;
 41 struct mempolicy;
 42 struct nameidata;
 43 struct nsproxy;
 44 struct perf_event_context;
 45 struct pid_namespace;
 46 struct pipe_inode_info;
 47 struct rcu_node;
 48 struct reclaim_state;
 49 struct robust_list_head;
 50 struct sched_attr;
 51 struct sched_param;
 52 struct seq_file;
 53 struct sighand_struct;
 54 struct signal_struct;
 55 struct task_delay_info;
 56 struct task_group;
 57 
 58 /*
 59  * Task state bitmask. NOTE! These bits are also
 60  * encoded in fs/proc/array.c: get_task_state().
 61  *
 62  * We have two separate sets of flags: task->state
 63  * is about runnability, while task->exit_state are
 64  * about the task exiting. Confusing, but this way
 65  * modifying one set can't modify the other one by
 66  * mistake.
 67  */
 68 
 69 /* Used in tsk->state: */
 70 #define TASK_RUNNING                    0x0000
 71 #define TASK_INTERRUPTIBLE              0x0001
 72 #define TASK_UNINTERRUPTIBLE            0x0002
 73 #define __TASK_STOPPED                  0x0004
 74 #define __TASK_TRACED                   0x0008
 75 /* Used in tsk->exit_state: */
 76 #define EXIT_DEAD                       0x0010
 77 #define EXIT_ZOMBIE                     0x0020
 78 #define EXIT_TRACE                      (EXIT_ZOMBIE | EXIT_DEAD)
 79 /* Used in tsk->state again: */
 80 #define TASK_PARKED                     0x0040
 81 #define TASK_DEAD                       0x0080
 82 #define TASK_WAKEKILL                   0x0100
 83 #define TASK_WAKING                     0x0200
 84 #define TASK_NOLOAD                     0x0400
 85 #define TASK_NEW                        0x0800
 86 #define TASK_STATE_MAX                  0x1000
 87 
 88 /* Convenience macros for the sake of set_current_state: */
 89 #define TASK_KILLABLE                   (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
 90 #define TASK_STOPPED                    (TASK_WAKEKILL | __TASK_STOPPED)
 91 #define TASK_TRACED                     (TASK_WAKEKILL | __TASK_TRACED)
 92 
 93 #define TASK_IDLE                       (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
 94 
 95 /* Convenience macros for the sake of wake_up(): */
 96 #define TASK_NORMAL                     (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
 97 
 98 /* get_task_state(): */
 99 #define TASK_REPORT                     (TASK_RUNNING | TASK_INTERRUPTIBLE | \
100                                          TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
101                                          __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
102                                          TASK_PARKED)
103 
104 #define task_is_traced(task)            ((task->state & __TASK_TRACED) != 0)
105 
106 #define task_is_stopped(task)           ((task->state & __TASK_STOPPED) != 0)
107 
108 #define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
109 
110 #define task_contributes_to_load(task)  ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
111                                          (task->flags & PF_FROZEN) == 0 && \
112                                          (task->state & TASK_NOLOAD) == 0)
113 
114 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
115 
116 /*
117  * Special states are those that do not use the normal wait-loop pattern. See
118  * the comment with set_special_state().
119  */
120 #define is_special_task_state(state)                            \
121         ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
122 
123 #define __set_current_state(state_value)                        \
124         do {                                                    \
125                 WARN_ON_ONCE(is_special_task_state(state_value));\
126                 current->task_state_change = _THIS_IP_;         \
127                 current->state = (state_value);                 \
128         } while (0)
129 
130 #define set_current_state(state_value)                          \
131         do {                                                    \
132                 WARN_ON_ONCE(is_special_task_state(state_value));\
133                 current->task_state_change = _THIS_IP_;         \
134                 smp_store_mb(current->state, (state_value));    \
135         } while (0)
136 
137 #define set_special_state(state_value)                                  \
138         do {                                                            \
139                 unsigned long flags; /* may shadow */                   \
140                 WARN_ON_ONCE(!is_special_task_state(state_value));      \
141                 raw_spin_lock_irqsave(&current->pi_lock, flags);        \
142                 current->task_state_change = _THIS_IP_;                 \
143                 current->state = (state_value);                         \
144                 raw_spin_unlock_irqrestore(&current->pi_lock, flags);   \
145         } while (0)
146 #else
147 /*
148  * set_current_state() includes a barrier so that the write of current->state
149  * is correctly serialised wrt the caller's subsequent test of whether to
150  * actually sleep:
151  *
152  *   for (;;) {
153  *      set_current_state(TASK_UNINTERRUPTIBLE);
154  *      if (!need_sleep)
155  *              break;
156  *
157  *      schedule();
158  *   }
159  *   __set_current_state(TASK_RUNNING);
160  *
161  * If the caller does not need such serialisation (because, for instance, the
162  * condition test and condition change and wakeup are under the same lock) then
163  * use __set_current_state().
164  *
165  * The above is typically ordered against the wakeup, which does:
166  *
167  *   need_sleep = false;
168  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
169  *
170  * Where wake_up_state() (and all other wakeup primitives) imply enough
171  * barriers to order the store of the variable against wakeup.
172  *
173  * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
174  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
175  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
176  *
177  * However, with slightly different timing the wakeup TASK_RUNNING store can
178  * also collide with the TASK_UNINTERRUPTIBLE store. Loosing that store is not
179  * a problem either because that will result in one extra go around the loop
180  * and our @cond test will save the day.
181  *
182  * Also see the comments of try_to_wake_up().
183  */
184 #define __set_current_state(state_value)                                \
185         current->state = (state_value)
186 
187 #define set_current_state(state_value)                                  \
188         smp_store_mb(current->state, (state_value))
189 
190 /*
191  * set_special_state() should be used for those states when the blocking task
192  * can not use the regular condition based wait-loop. In that case we must
193  * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
194  * will not collide with our state change.
195  */
196 #define set_special_state(state_value)                                  \
197         do {                                                            \
198                 unsigned long flags; /* may shadow */                   \
199                 raw_spin_lock_irqsave(&current->pi_lock, flags);        \
200                 current->state = (state_value);                         \
201                 raw_spin_unlock_irqrestore(&current->pi_lock, flags);   \
202         } while (0)
203 
204 #endif
205 
206 /* Task command name length: */
207 #define TASK_COMM_LEN                   16
208 
209 extern void scheduler_tick(void);
210 
211 #define MAX_SCHEDULE_TIMEOUT            LONG_MAX
212 
213 extern long schedule_timeout(long timeout);
214 extern long schedule_timeout_interruptible(long timeout);
215 extern long schedule_timeout_killable(long timeout);
216 extern long schedule_timeout_uninterruptible(long timeout);
217 extern long schedule_timeout_idle(long timeout);
218 asmlinkage void schedule(void);
219 extern void schedule_preempt_disabled(void);
220 
221 extern int __must_check io_schedule_prepare(void);
222 extern void io_schedule_finish(int token);
223 extern long io_schedule_timeout(long timeout);
224 extern void io_schedule(void);
225 
226 /**
227  * struct prev_cputime - snapshot of system and user cputime
228  * @utime: time spent in user mode
229  * @stime: time spent in system mode
230  * @lock: protects the above two fields
231  *
232  * Stores previous user/system time values such that we can guarantee
233  * monotonicity.
234  */
235 struct prev_cputime {
236 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
237         u64                             utime;
238         u64                             stime;
239         raw_spinlock_t                  lock;
240 #endif
241 };
242 
243 /**
244  * struct task_cputime - collected CPU time counts
245  * @utime:              time spent in user mode, in nanoseconds
246  * @stime:              time spent in kernel mode, in nanoseconds
247  * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
248  *
249  * This structure groups together three kinds of CPU time that are tracked for
250  * threads and thread groups.  Most things considering CPU time want to group
251  * these counts together and treat all three of them in parallel.
252  */
253 struct task_cputime {
254         u64                             utime;
255         u64                             stime;
256         unsigned long long              sum_exec_runtime;
257 };
258 
259 /* Alternate field names when used on cache expirations: */
260 #define virt_exp                        utime
261 #define prof_exp                        stime
262 #define sched_exp                       sum_exec_runtime
263 
264 enum vtime_state {
265         /* Task is sleeping or running in a CPU with VTIME inactive: */
266         VTIME_INACTIVE = 0,
267         /* Task runs in userspace in a CPU with VTIME active: */
268         VTIME_USER,
269         /* Task runs in kernelspace in a CPU with VTIME active: */
270         VTIME_SYS,
271 };
272 
273 struct vtime {
274         seqcount_t              seqcount;
275         unsigned long long      starttime;
276         enum vtime_state        state;
277         u64                     utime;
278         u64                     stime;
279         u64                     gtime;
280 };
281 
282 struct sched_info {
283 #ifdef CONFIG_SCHED_INFO
284         /* Cumulative counters: */
285 
286         /* # of times we have run on this CPU: */
287         unsigned long                   pcount;
288 
289         /* Time spent waiting on a runqueue: */
290         unsigned long long              run_delay;
291 
292         /* Timestamps: */
293 
294         /* When did we last run on a CPU? */
295         unsigned long long              last_arrival;
296 
297         /* When were we last queued to run? */
298         unsigned long long              last_queued;
299 
300 #endif /* CONFIG_SCHED_INFO */
301 };
302 
303 /*
304  * Integer metrics need fixed point arithmetic, e.g., sched/fair
305  * has a few: load, load_avg, util_avg, freq, and capacity.
306  *
307  * We define a basic fixed point arithmetic range, and then formalize
308  * all these metrics based on that basic range.
309  */
310 # define SCHED_FIXEDPOINT_SHIFT         10
311 # define SCHED_FIXEDPOINT_SCALE         (1L << SCHED_FIXEDPOINT_SHIFT)
312 
313 struct load_weight {
314         unsigned long                   weight;
315         u32                             inv_weight;
316 };
317 
318 /**
319  * struct util_est - Estimation utilization of FAIR tasks
320  * @enqueued: instantaneous estimated utilization of a task/cpu
321  * @ewma:     the Exponential Weighted Moving Average (EWMA)
322  *            utilization of a task
323  *
324  * Support data structure to track an Exponential Weighted Moving Average
325  * (EWMA) of a FAIR task's utilization. New samples are added to the moving
326  * average each time a task completes an activation. Sample's weight is chosen
327  * so that the EWMA will be relatively insensitive to transient changes to the
328  * task's workload.
329  *
330  * The enqueued attribute has a slightly different meaning for tasks and cpus:
331  * - task:   the task's util_avg at last task dequeue time
332  * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
333  * Thus, the util_est.enqueued of a task represents the contribution on the
334  * estimated utilization of the CPU where that task is currently enqueued.
335  *
336  * Only for tasks we track a moving average of the past instantaneous
337  * estimated utilization. This allows to absorb sporadic drops in utilization
338  * of an otherwise almost periodic task.
339  */
340 struct util_est {
341         unsigned int                    enqueued;
342         unsigned int                    ewma;
343 #define UTIL_EST_WEIGHT_SHIFT           2
344 } __attribute__((__aligned__(sizeof(u64))));
345 
346 /*
347  * The load_avg/util_avg accumulates an infinite geometric series
348  * (see __update_load_avg() in kernel/sched/fair.c).
349  *
350  * [load_avg definition]
351  *
352  *   load_avg = runnable% * scale_load_down(load)
353  *
354  * where runnable% is the time ratio that a sched_entity is runnable.
355  * For cfs_rq, it is the aggregated load_avg of all runnable and
356  * blocked sched_entities.
357  *
358  * load_avg may also take frequency scaling into account:
359  *
360  *   load_avg = runnable% * scale_load_down(load) * freq%
361  *
362  * where freq% is the CPU frequency normalized to the highest frequency.
363  *
364  * [util_avg definition]
365  *
366  *   util_avg = running% * SCHED_CAPACITY_SCALE
367  *
368  * where running% is the time ratio that a sched_entity is running on
369  * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
370  * and blocked sched_entities.
371  *
372  * util_avg may also factor frequency scaling and CPU capacity scaling:
373  *
374  *   util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
375  *
376  * where freq% is the same as above, and capacity% is the CPU capacity
377  * normalized to the greatest capacity (due to uarch differences, etc).
378  *
379  * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
380  * themselves are in the range of [0, 1]. To do fixed point arithmetics,
381  * we therefore scale them to as large a range as necessary. This is for
382  * example reflected by util_avg's SCHED_CAPACITY_SCALE.
383  *
384  * [Overflow issue]
385  *
386  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
387  * with the highest load (=88761), always runnable on a single cfs_rq,
388  * and should not overflow as the number already hits PID_MAX_LIMIT.
389  *
390  * For all other cases (including 32-bit kernels), struct load_weight's
391  * weight will overflow first before we do, because:
392  *
393  *    Max(load_avg) <= Max(load.weight)
394  *
395  * Then it is the load_weight's responsibility to consider overflow
396  * issues.
397  */
398 struct sched_avg {
399         u64                             last_update_time;
400         u64                             load_sum;
401         u64                             runnable_load_sum;
402         u32                             util_sum;
403         u32                             period_contrib;
404         unsigned long                   load_avg;
405         unsigned long                   runnable_load_avg;
406         unsigned long                   util_avg;
407         struct util_est                 util_est;
408 } ____cacheline_aligned;
409 
410 struct sched_statistics {
411 #ifdef CONFIG_SCHEDSTATS
412         u64                             wait_start;
413         u64                             wait_max;
414         u64                             wait_count;
415         u64                             wait_sum;
416         u64                             iowait_count;
417         u64                             iowait_sum;
418 
419         u64                             sleep_start;
420         u64                             sleep_max;
421         s64                             sum_sleep_runtime;
422 
423         u64                             block_start;
424         u64                             block_max;
425         u64                             exec_max;
426         u64                             slice_max;
427 
428         u64                             nr_migrations_cold;
429         u64                             nr_failed_migrations_affine;
430         u64                             nr_failed_migrations_running;
431         u64                             nr_failed_migrations_hot;
432         u64                             nr_forced_migrations;
433 
434         u64                             nr_wakeups;
435         u64                             nr_wakeups_sync;
436         u64                             nr_wakeups_migrate;
437         u64                             nr_wakeups_local;
438         u64                             nr_wakeups_remote;
439         u64                             nr_wakeups_affine;
440         u64                             nr_wakeups_affine_attempts;
441         u64                             nr_wakeups_passive;
442         u64                             nr_wakeups_idle;
443 #endif
444 };
445 
446 struct sched_entity {
447         /* For load-balancing: */
448         struct load_weight              load;
449         unsigned long                   runnable_weight;
450         struct rb_node                  run_node;
451         struct list_head                group_node;
452         unsigned int                    on_rq;
453 
454         u64                             exec_start;
455         u64                             sum_exec_runtime;
456         u64                             vruntime;
457         u64                             prev_sum_exec_runtime;
458 
459         u64                             nr_migrations;
460 
461         struct sched_statistics         statistics;
462 
463 #ifdef CONFIG_FAIR_GROUP_SCHED
464         int                             depth;
465         struct sched_entity             *parent;
466         /* rq on which this entity is (to be) queued: */
467         struct cfs_rq                   *cfs_rq;
468         /* rq "owned" by this entity/group: */
469         struct cfs_rq                   *my_q;
470 #endif
471 
472 #ifdef CONFIG_SMP
473         /*
474          * Per entity load average tracking.
475          *
476          * Put into separate cache line so it does not
477          * collide with read-mostly values above.
478          */
479         struct sched_avg                avg;
480 #endif
481 };
482 
483 struct sched_rt_entity {
484         struct list_head                run_list;
485         unsigned long                   timeout;
486         unsigned long                   watchdog_stamp;
487         unsigned int                    time_slice;
488         unsigned short                  on_rq;
489         unsigned short                  on_list;
490 
491         struct sched_rt_entity          *back;
492 #ifdef CONFIG_RT_GROUP_SCHED
493         struct sched_rt_entity          *parent;
494         /* rq on which this entity is (to be) queued: */
495         struct rt_rq                    *rt_rq;
496         /* rq "owned" by this entity/group: */
497         struct rt_rq                    *my_q;
498 #endif
499 } __randomize_layout;
500 
501 struct sched_dl_entity {
502         struct rb_node                  rb_node;
503 
504         /*
505          * Original scheduling parameters. Copied here from sched_attr
506          * during sched_setattr(), they will remain the same until
507          * the next sched_setattr().
508          */
509         u64                             dl_runtime;     /* Maximum runtime for each instance    */
510         u64                             dl_deadline;    /* Relative deadline of each instance   */
511         u64                             dl_period;      /* Separation of two instances (period) */
512         u64                             dl_bw;          /* dl_runtime / dl_period               */
513         u64                             dl_density;     /* dl_runtime / dl_deadline             */
514 
515         /*
516          * Actual scheduling parameters. Initialized with the values above,
517          * they are continously updated during task execution. Note that
518          * the remaining runtime could be < 0 in case we are in overrun.
519          */
520         s64                             runtime;        /* Remaining runtime for this instance  */
521         u64                             deadline;       /* Absolute deadline for this instance  */
522         unsigned int                    flags;          /* Specifying the scheduler behaviour   */
523 
524         /*
525          * Some bool flags:
526          *
527          * @dl_throttled tells if we exhausted the runtime. If so, the
528          * task has to wait for a replenishment to be performed at the
529          * next firing of dl_timer.
530          *
531          * @dl_boosted tells if we are boosted due to DI. If so we are
532          * outside bandwidth enforcement mechanism (but only until we
533          * exit the critical section);
534          *
535          * @dl_yielded tells if task gave up the CPU before consuming
536          * all its available runtime during the last job.
537          *
538          * @dl_non_contending tells if the task is inactive while still
539          * contributing to the active utilization. In other words, it
540          * indicates if the inactive timer has been armed and its handler
541          * has not been executed yet. This flag is useful to avoid race
542          * conditions between the inactive timer handler and the wakeup
543          * code.
544          *
545          * @dl_overrun tells if the task asked to be informed about runtime
546          * overruns.
547          */
548         unsigned int                    dl_throttled      : 1;
549         unsigned int                    dl_boosted        : 1;
550         unsigned int                    dl_yielded        : 1;
551         unsigned int                    dl_non_contending : 1;
552         unsigned int                    dl_overrun        : 1;
553 
554         /*
555          * Bandwidth enforcement timer. Each -deadline task has its
556          * own bandwidth to be enforced, thus we need one timer per task.
557          */
558         struct hrtimer                  dl_timer;
559 
560         /*
561          * Inactive timer, responsible for decreasing the active utilization
562          * at the "0-lag time". When a -deadline task blocks, it contributes
563          * to GRUB's active utilization until the "0-lag time", hence a
564          * timer is needed to decrease the active utilization at the correct
565          * time.
566          */
567         struct hrtimer inactive_timer;
568 };
569 
570 union rcu_special {
571         struct {
572                 u8                      blocked;
573                 u8                      need_qs;
574                 u8                      exp_need_qs;
575 
576                 /* Otherwise the compiler can store garbage here: */
577                 u8                      pad;
578         } b; /* Bits. */
579         u32 s; /* Set of bits. */
580 };
581 
582 enum perf_event_task_context {
583         perf_invalid_context = -1,
584         perf_hw_context = 0,
585         perf_sw_context,
586         perf_nr_task_contexts,
587 };
588 
589 struct wake_q_node {
590         struct wake_q_node *next;
591 };
592 
593 struct task_struct {
594 #ifdef CONFIG_THREAD_INFO_IN_TASK
595         /*
596          * For reasons of header soup (see current_thread_info()), this
597          * must be the first element of task_struct.
598          */
599         struct thread_info              thread_info;
600 #endif
601         /* -1 unrunnable, 0 runnable, >0 stopped: */
602         volatile long                   state;
603 
604         /*
605          * This begins the randomizable portion of task_struct. Only
606          * scheduling-critical items should be added above here.
607          */
608         randomized_struct_fields_start
609 
610         void                            *stack;
611         atomic_t                        usage;
612         /* Per task flags (PF_*), defined further below: */
613         unsigned int                    flags;
614         unsigned int                    ptrace;
615 
616 #ifdef CONFIG_SMP
617         struct llist_node               wake_entry;
618         int                             on_cpu;
619 #ifdef CONFIG_THREAD_INFO_IN_TASK
620         /* Current CPU: */
621         unsigned int                    cpu;
622 #endif
623         unsigned int                    wakee_flips;
624         unsigned long                   wakee_flip_decay_ts;
625         struct task_struct              *last_wakee;
626 
627         /*
628          * recent_used_cpu is initially set as the last CPU used by a task
629          * that wakes affine another task. Waker/wakee relationships can
630          * push tasks around a CPU where each wakeup moves to the next one.
631          * Tracking a recently used CPU allows a quick search for a recently
632          * used CPU that may be idle.
633          */
634         int                             recent_used_cpu;
635         int                             wake_cpu;
636 #endif
637         int                             on_rq;
638 
639         int                             prio;
640         int                             static_prio;
641         int                             normal_prio;
642         unsigned int                    rt_priority;
643 
644         const struct sched_class        *sched_class;
645         struct sched_entity             se;
646         struct sched_rt_entity          rt;
647 #ifdef CONFIG_CGROUP_SCHED
648         struct task_group               *sched_task_group;
649 #endif
650         struct sched_dl_entity          dl;
651 
652 #ifdef CONFIG_PREEMPT_NOTIFIERS
653         /* List of struct preempt_notifier: */
654         struct hlist_head               preempt_notifiers;
655 #endif
656 
657 #ifdef CONFIG_BLK_DEV_IO_TRACE
658         unsigned int                    btrace_seq;
659 #endif
660 
661         unsigned int                    policy;
662         int                             nr_cpus_allowed;
663         cpumask_t                       cpus_allowed;
664 
665 #ifdef CONFIG_PREEMPT_RCU
666         int                             rcu_read_lock_nesting;
667         union rcu_special               rcu_read_unlock_special;
668         struct list_head                rcu_node_entry;
669         struct rcu_node                 *rcu_blocked_node;
670 #endif /* #ifdef CONFIG_PREEMPT_RCU */
671 
672 #ifdef CONFIG_TASKS_RCU
673         unsigned long                   rcu_tasks_nvcsw;
674         u8                              rcu_tasks_holdout;
675         u8                              rcu_tasks_idx;
676         int                             rcu_tasks_idle_cpu;
677         struct list_head                rcu_tasks_holdout_list;
678 #endif /* #ifdef CONFIG_TASKS_RCU */
679 
680         struct sched_info               sched_info;
681 
682         struct list_head                tasks;
683 #ifdef CONFIG_SMP
684         struct plist_node               pushable_tasks;
685         struct rb_node                  pushable_dl_tasks;
686 #endif
687 
688         struct mm_struct                *mm;
689         struct mm_struct                *active_mm;
690 
691         /* Per-thread vma caching: */
692         struct vmacache                 vmacache;
693 
694 #ifdef SPLIT_RSS_COUNTING
695         struct task_rss_stat            rss_stat;
696 #endif
697         int                             exit_state;
698         int                             exit_code;
699         int                             exit_signal;
700         /* The signal sent when the parent dies: */
701         int                             pdeath_signal;
702         /* JOBCTL_*, siglock protected: */
703         unsigned long                   jobctl;
704 
705         /* Used for emulating ABI behavior of previous Linux versions: */
706         unsigned int                    personality;
707 
708         /* Scheduler bits, serialized by scheduler locks: */
709         unsigned                        sched_reset_on_fork:1;
710         unsigned                        sched_contributes_to_load:1;
711         unsigned                        sched_migrated:1;
712         unsigned                        sched_remote_wakeup:1;
713         /* Force alignment to the next boundary: */
714         unsigned                        :0;
715 
716         /* Unserialized, strictly 'current' */
717 
718         /* Bit to tell LSMs we're in execve(): */
719         unsigned                        in_execve:1;
720         unsigned                        in_iowait:1;
721 #ifndef TIF_RESTORE_SIGMASK
722         unsigned                        restore_sigmask:1;
723 #endif
724 #ifdef CONFIG_MEMCG
725         unsigned                        memcg_may_oom:1;
726 #ifndef CONFIG_SLOB
727         unsigned                        memcg_kmem_skip_account:1;
728 #endif
729 #endif
730 #ifdef CONFIG_COMPAT_BRK
731         unsigned                        brk_randomized:1;
732 #endif
733 #ifdef CONFIG_CGROUPS
734         /* disallow userland-initiated cgroup migration */
735         unsigned                        no_cgroup_migration:1;
736 #endif
737 
738         unsigned long                   atomic_flags; /* Flags requiring atomic access. */
739 
740         struct restart_block            restart_block;
741 
742         pid_t                           pid;
743         pid_t                           tgid;
744 
745 #ifdef CONFIG_CC_STACKPROTECTOR
746         /* Canary value for the -fstack-protector GCC feature: */
747         unsigned long                   stack_canary;
748 #endif
749         /*
750          * Pointers to the (original) parent process, youngest child, younger sibling,
751          * older sibling, respectively.  (p->father can be replaced with
752          * p->real_parent->pid)
753          */
754 
755         /* Real parent process: */
756         struct task_struct __rcu        *real_parent;
757 
758         /* Recipient of SIGCHLD, wait4() reports: */
759         struct task_struct __rcu        *parent;
760 
761         /*
762          * Children/sibling form the list of natural children:
763          */
764         struct list_head                children;
765         struct list_head                sibling;
766         struct task_struct              *group_leader;
767 
768         /*
769          * 'ptraced' is the list of tasks this task is using ptrace() on.
770          *
771          * This includes both natural children and PTRACE_ATTACH targets.
772          * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
773          */
774         struct list_head                ptraced;
775         struct list_head                ptrace_entry;
776 
777         /* PID/PID hash table linkage. */
778         struct pid_link                 pids[PIDTYPE_MAX];
779         struct list_head                thread_group;
780         struct list_head                thread_node;
781 
782         struct completion               *vfork_done;
783 
784         /* CLONE_CHILD_SETTID: */
785         int __user                      *set_child_tid;
786 
787         /* CLONE_CHILD_CLEARTID: */
788         int __user                      *clear_child_tid;
789 
790         u64                             utime;
791         u64                             stime;
792 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
793         u64                             utimescaled;
794         u64                             stimescaled;
795 #endif
796         u64                             gtime;
797         struct prev_cputime             prev_cputime;
798 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
799         struct vtime                    vtime;
800 #endif
801 
802 #ifdef CONFIG_NO_HZ_FULL
803         atomic_t                        tick_dep_mask;
804 #endif
805         /* Context switch counts: */
806         unsigned long                   nvcsw;
807         unsigned long                   nivcsw;
808 
809         /* Monotonic time in nsecs: */
810         u64                             start_time;
811 
812         /* Boot based time in nsecs: */
813         u64                             real_start_time;
814 
815         /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
816         unsigned long                   min_flt;
817         unsigned long                   maj_flt;
818 
819 #ifdef CONFIG_POSIX_TIMERS
820         struct task_cputime             cputime_expires;
821         struct list_head                cpu_timers[3];
822 #endif
823 
824         /* Process credentials: */
825 
826         /* Tracer's credentials at attach: */
827         const struct cred __rcu         *ptracer_cred;
828 
829         /* Objective and real subjective task credentials (COW): */
830         const struct cred __rcu         *real_cred;
831 
832         /* Effective (overridable) subjective task credentials (COW): */
833         const struct cred __rcu         *cred;
834 
835         /*
836          * executable name, excluding path.
837          *
838          * - normally initialized setup_new_exec()
839          * - access it with [gs]et_task_comm()
840          * - lock it with task_lock()
841          */
842         char                            comm[TASK_COMM_LEN];
843 
844         struct nameidata                *nameidata;
845 
846 #ifdef CONFIG_SYSVIPC
847         struct sysv_sem                 sysvsem;
848         struct sysv_shm                 sysvshm;
849 #endif
850 #ifdef CONFIG_DETECT_HUNG_TASK
851         unsigned long                   last_switch_count;
852 #endif
853         /* Filesystem information: */
854         struct fs_struct                *fs;
855 
856         /* Open file information: */
857         struct files_struct             *files;
858 
859         /* Namespaces: */
860         struct nsproxy                  *nsproxy;
861 
862         /* Signal handlers: */
863         struct signal_struct            *signal;
864         struct sighand_struct           *sighand;
865         sigset_t                        blocked;
866         sigset_t                        real_blocked;
867         /* Restored if set_restore_sigmask() was used: */
868         sigset_t                        saved_sigmask;
869         struct sigpending               pending;
870         unsigned long                   sas_ss_sp;
871         size_t                          sas_ss_size;
872         unsigned int                    sas_ss_flags;
873 
874         struct callback_head            *task_works;
875 
876         struct audit_context            *audit_context;
877 #ifdef CONFIG_AUDITSYSCALL
878         kuid_t                          loginuid;
879         unsigned int                    sessionid;
880 #endif
881         struct seccomp                  seccomp;
882 
883         /* Thread group tracking: */
884         u32                             parent_exec_id;
885         u32                             self_exec_id;
886 
887         /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
888         spinlock_t                      alloc_lock;
889 
890         /* Protection of the PI data structures: */
891         raw_spinlock_t                  pi_lock;
892 
893         struct wake_q_node              wake_q;
894 
895 #ifdef CONFIG_RT_MUTEXES
896         /* PI waiters blocked on a rt_mutex held by this task: */
897         struct rb_root_cached           pi_waiters;
898         /* Updated under owner's pi_lock and rq lock */
899         struct task_struct              *pi_top_task;
900         /* Deadlock detection and priority inheritance handling: */
901         struct rt_mutex_waiter          *pi_blocked_on;
902 #endif
903 
904 #ifdef CONFIG_DEBUG_MUTEXES
905         /* Mutex deadlock detection: */
906         struct mutex_waiter             *blocked_on;
907 #endif
908 
909 #ifdef CONFIG_TRACE_IRQFLAGS
910         unsigned int                    irq_events;
911         unsigned long                   hardirq_enable_ip;
912         unsigned long                   hardirq_disable_ip;
913         unsigned int                    hardirq_enable_event;
914         unsigned int                    hardirq_disable_event;
915         int                             hardirqs_enabled;
916         int                             hardirq_context;
917         unsigned long                   softirq_disable_ip;
918         unsigned long                   softirq_enable_ip;
919         unsigned int                    softirq_disable_event;
920         unsigned int                    softirq_enable_event;
921         int                             softirqs_enabled;
922         int                             softirq_context;
923 #endif
924 
925 #ifdef CONFIG_LOCKDEP
926 # define MAX_LOCK_DEPTH                 48UL
927         u64                             curr_chain_key;
928         int                             lockdep_depth;
929         unsigned int                    lockdep_recursion;
930         struct held_lock                held_locks[MAX_LOCK_DEPTH];
931 #endif
932 
933 #ifdef CONFIG_UBSAN
934         unsigned int                    in_ubsan;
935 #endif
936 
937         /* Journalling filesystem info: */
938         void                            *journal_info;
939 
940         /* Stacked block device info: */
941         struct bio_list                 *bio_list;
942 
943 #ifdef CONFIG_BLOCK
944         /* Stack plugging: */
945         struct blk_plug                 *plug;
946 #endif
947 
948         /* VM state: */
949         struct reclaim_state            *reclaim_state;
950 
951         struct backing_dev_info         *backing_dev_info;
952 
953         struct io_context               *io_context;
954 
955         /* Ptrace state: */
956         unsigned long                   ptrace_message;
957         siginfo_t                       *last_siginfo;
958 
959         struct task_io_accounting       ioac;
960 #ifdef CONFIG_TASK_XACCT
961         /* Accumulated RSS usage: */
962         u64                             acct_rss_mem1;
963         /* Accumulated virtual memory usage: */
964         u64                             acct_vm_mem1;
965         /* stime + utime since last update: */
966         u64                             acct_timexpd;
967 #endif
968 #ifdef CONFIG_CPUSETS
969         /* Protected by ->alloc_lock: */
970         nodemask_t                      mems_allowed;
971         /* Seqence number to catch updates: */
972         seqcount_t                      mems_allowed_seq;
973         int                             cpuset_mem_spread_rotor;
974         int                             cpuset_slab_spread_rotor;
975 #endif
976 #ifdef CONFIG_CGROUPS
977         /* Control Group info protected by css_set_lock: */
978         struct css_set __rcu            *cgroups;
979         /* cg_list protected by css_set_lock and tsk->alloc_lock: */
980         struct list_head                cg_list;
981 #endif
982 #ifdef CONFIG_INTEL_RDT
983         u32                             closid;
984         u32                             rmid;
985 #endif
986 #ifdef CONFIG_FUTEX
987         struct robust_list_head __user  *robust_list;
988 #ifdef CONFIG_COMPAT
989         struct compat_robust_list_head __user *compat_robust_list;
990 #endif
991         struct list_head                pi_state_list;
992         struct futex_pi_state           *pi_state_cache;
993 #endif
994 #ifdef CONFIG_PERF_EVENTS
995         struct perf_event_context       *perf_event_ctxp[perf_nr_task_contexts];
996         struct mutex                    perf_event_mutex;
997         struct list_head                perf_event_list;
998 #endif
999 #ifdef CONFIG_DEBUG_PREEMPT
1000         unsigned long                   preempt_disable_ip;
1001 #endif
1002 #ifdef CONFIG_NUMA
1003         /* Protected by alloc_lock: */
1004         struct mempolicy                *mempolicy;
1005         short                           il_prev;
1006         short                           pref_node_fork;
1007 #endif
1008 #ifdef CONFIG_NUMA_BALANCING
1009         int                             numa_scan_seq;
1010         unsigned int                    numa_scan_period;
1011         unsigned int                    numa_scan_period_max;
1012         int                             numa_preferred_nid;
1013         unsigned long                   numa_migrate_retry;
1014         /* Migration stamp: */
1015         u64                             node_stamp;
1016         u64                             last_task_numa_placement;
1017         u64                             last_sum_exec_runtime;
1018         struct callback_head            numa_work;
1019 
1020         struct list_head                numa_entry;
1021         struct numa_group               *numa_group;
1022 
1023         /*
1024          * numa_faults is an array split into four regions:
1025          * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1026          * in this precise order.
1027          *
1028          * faults_memory: Exponential decaying average of faults on a per-node
1029          * basis. Scheduling placement decisions are made based on these
1030          * counts. The values remain static for the duration of a PTE scan.
1031          * faults_cpu: Track the nodes the process was running on when a NUMA
1032          * hinting fault was incurred.
1033          * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1034          * during the current scan window. When the scan completes, the counts
1035          * in faults_memory and faults_cpu decay and these values are copied.
1036          */
1037         unsigned long                   *numa_faults;
1038         unsigned long                   total_numa_faults;
1039 
1040         /*
1041          * numa_faults_locality tracks if faults recorded during the last
1042          * scan window were remote/local or failed to migrate. The task scan
1043          * period is adapted based on the locality of the faults with different
1044          * weights depending on whether they were shared or private faults
1045          */
1046         unsigned long                   numa_faults_locality[3];
1047 
1048         unsigned long                   numa_pages_migrated;
1049 #endif /* CONFIG_NUMA_BALANCING */
1050 
1051         struct tlbflush_unmap_batch     tlb_ubc;
1052 
1053         struct rcu_head                 rcu;
1054 
1055         /* Cache last used pipe for splice(): */
1056         struct pipe_inode_info          *splice_pipe;
1057 
1058         struct page_frag                task_frag;
1059 
1060 #ifdef CONFIG_TASK_DELAY_ACCT
1061         struct task_delay_info          *delays;
1062 #endif
1063 
1064 #ifdef CONFIG_FAULT_INJECTION
1065         int                             make_it_fail;
1066         unsigned int                    fail_nth;
1067 #endif
1068         /*
1069          * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1070          * balance_dirty_pages() for a dirty throttling pause:
1071          */
1072         int                             nr_dirtied;
1073         int                             nr_dirtied_pause;
1074         /* Start of a write-and-pause period: */
1075         unsigned long                   dirty_paused_when;
1076 
1077 #ifdef CONFIG_LATENCYTOP
1078         int                             latency_record_count;
1079         struct latency_record           latency_record[LT_SAVECOUNT];
1080 #endif
1081         /*
1082          * Time slack values; these are used to round up poll() and
1083          * select() etc timeout values. These are in nanoseconds.
1084          */
1085         u64                             timer_slack_ns;
1086         u64                             default_timer_slack_ns;
1087 
1088 #ifdef CONFIG_KASAN
1089         unsigned int                    kasan_depth;
1090 #endif
1091 
1092 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1093         /* Index of current stored address in ret_stack: */
1094         int                             curr_ret_stack;
1095 
1096         /* Stack of return addresses for return function tracing: */
1097         struct ftrace_ret_stack         *ret_stack;
1098 
1099         /* Timestamp for last schedule: */
1100         unsigned long long              ftrace_timestamp;
1101 
1102         /*
1103          * Number of functions that haven't been traced
1104          * because of depth overrun:
1105          */
1106         atomic_t                        trace_overrun;
1107 
1108         /* Pause tracing: */
1109         atomic_t                        tracing_graph_pause;
1110 #endif
1111 
1112 #ifdef CONFIG_TRACING
1113         /* State flags for use by tracers: */
1114         unsigned long                   trace;
1115 
1116         /* Bitmask and counter of trace recursion: */
1117         unsigned long                   trace_recursion;
1118 #endif /* CONFIG_TRACING */
1119 
1120 #ifdef CONFIG_KCOV
1121         /* Coverage collection mode enabled for this task (0 if disabled): */
1122         enum kcov_mode                  kcov_mode;
1123 
1124         /* Size of the kcov_area: */
1125         unsigned int                    kcov_size;
1126 
1127         /* Buffer for coverage collection: */
1128         void                            *kcov_area;
1129 
1130         /* KCOV descriptor wired with this task or NULL: */
1131         struct kcov                     *kcov;
1132 #endif
1133 
1134 #ifdef CONFIG_MEMCG
1135         struct mem_cgroup               *memcg_in_oom;
1136         gfp_t                           memcg_oom_gfp_mask;
1137         int                             memcg_oom_order;
1138 
1139         /* Number of pages to reclaim on returning to userland: */
1140         unsigned int                    memcg_nr_pages_over_high;
1141 #endif
1142 
1143 #ifdef CONFIG_UPROBES
1144         struct uprobe_task              *utask;
1145 #endif
1146 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1147         unsigned int                    sequential_io;
1148         unsigned int                    sequential_io_avg;
1149 #endif
1150 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1151         unsigned long                   task_state_change;
1152 #endif
1153         int                             pagefault_disabled;
1154 #ifdef CONFIG_MMU
1155         struct task_struct              *oom_reaper_list;
1156 #endif
1157 #ifdef CONFIG_VMAP_STACK
1158         struct vm_struct                *stack_vm_area;
1159 #endif
1160 #ifdef CONFIG_THREAD_INFO_IN_TASK
1161         /* A live task holds one reference: */
1162         atomic_t                        stack_refcount;
1163 #endif
1164 #ifdef CONFIG_LIVEPATCH
1165         int patch_state;
1166 #endif
1167 #ifdef CONFIG_SECURITY
1168         /* Used by LSM modules for access restriction: */
1169         void                            *security;
1170 #endif
1171 #if defined(CONFIG_CCSECURITY) && !defined(CONFIG_CCSECURITY_USE_EXTERNAL_TASK_SECURITY)
1172         struct ccs_domain_info          *ccs_domain_info;
1173         u32                             ccs_flags;
1174 #endif
1175 
1176         /*
1177          * New fields for task_struct should be added above here, so that
1178          * they are included in the randomized portion of task_struct.
1179          */
1180         randomized_struct_fields_end
1181 
1182         /* CPU-specific state of this task: */
1183         struct thread_struct            thread;
1184 
1185         /*
1186          * WARNING: on x86, 'thread_struct' contains a variable-sized
1187          * structure.  It *MUST* be at the end of 'task_struct'.
1188          *
1189          * Do not put anything below here!
1190          */
1191 };
1192 
1193 static inline struct pid *task_pid(struct task_struct *task)
1194 {
1195         return task->pids[PIDTYPE_PID].pid;
1196 }
1197 
1198 static inline struct pid *task_tgid(struct task_struct *task)
1199 {
1200         return task->group_leader->pids[PIDTYPE_PID].pid;
1201 }
1202 
1203 /*
1204  * Without tasklist or RCU lock it is not safe to dereference
1205  * the result of task_pgrp/task_session even if task == current,
1206  * we can race with another thread doing sys_setsid/sys_setpgid.
1207  */
1208 static inline struct pid *task_pgrp(struct task_struct *task)
1209 {
1210         return task->group_leader->pids[PIDTYPE_PGID].pid;
1211 }
1212 
1213 static inline struct pid *task_session(struct task_struct *task)
1214 {
1215         return task->group_leader->pids[PIDTYPE_SID].pid;
1216 }
1217 
1218 /*
1219  * the helpers to get the task's different pids as they are seen
1220  * from various namespaces
1221  *
1222  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1223  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1224  *                     current.
1225  * task_xid_nr_ns()  : id seen from the ns specified;
1226  *
1227  * see also pid_nr() etc in include/linux/pid.h
1228  */
1229 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1230 
1231 static inline pid_t task_pid_nr(struct task_struct *tsk)
1232 {
1233         return tsk->pid;
1234 }
1235 
1236 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1237 {
1238         return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1239 }
1240 
1241 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1242 {
1243         return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1244 }
1245 
1246 
1247 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1248 {
1249         return tsk->tgid;
1250 }
1251 
1252 /**
1253  * pid_alive - check that a task structure is not stale
1254  * @p: Task structure to be checked.
1255  *
1256  * Test if a process is not yet dead (at most zombie state)
1257  * If pid_alive fails, then pointers within the task structure
1258  * can be stale and must not be dereferenced.
1259  *
1260  * Return: 1 if the process is alive. 0 otherwise.
1261  */
1262 static inline int pid_alive(const struct task_struct *p)
1263 {
1264         return p->pids[PIDTYPE_PID].pid != NULL;
1265 }
1266 
1267 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1268 {
1269         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1270 }
1271 
1272 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1273 {
1274         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1275 }
1276 
1277 
1278 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1279 {
1280         return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1281 }
1282 
1283 static inline pid_t task_session_vnr(struct task_struct *tsk)
1284 {
1285         return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1286 }
1287 
1288 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1289 {
1290         return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, ns);
1291 }
1292 
1293 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1294 {
1295         return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, NULL);
1296 }
1297 
1298 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1299 {
1300         pid_t pid = 0;
1301 
1302         rcu_read_lock();
1303         if (pid_alive(tsk))
1304                 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1305         rcu_read_unlock();
1306 
1307         return pid;
1308 }
1309 
1310 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1311 {
1312         return task_ppid_nr_ns(tsk, &init_pid_ns);
1313 }
1314 
1315 /* Obsolete, do not use: */
1316 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1317 {
1318         return task_pgrp_nr_ns(tsk, &init_pid_ns);
1319 }
1320 
1321 #define TASK_REPORT_IDLE        (TASK_REPORT + 1)
1322 #define TASK_REPORT_MAX         (TASK_REPORT_IDLE << 1)
1323 
1324 static inline unsigned int task_state_index(struct task_struct *tsk)
1325 {
1326         unsigned int tsk_state = READ_ONCE(tsk->state);
1327         unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1328 
1329         BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1330 
1331         if (tsk_state == TASK_IDLE)
1332                 state = TASK_REPORT_IDLE;
1333 
1334         return fls(state);
1335 }
1336 
1337 static inline char task_index_to_char(unsigned int state)
1338 {
1339         static const char state_char[] = "RSDTtXZPI";
1340 
1341         BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1342 
1343         return state_char[state];
1344 }
1345 
1346 static inline char task_state_to_char(struct task_struct *tsk)
1347 {
1348         return task_index_to_char(task_state_index(tsk));
1349 }
1350 
1351 /**
1352  * is_global_init - check if a task structure is init. Since init
1353  * is free to have sub-threads we need to check tgid.
1354  * @tsk: Task structure to be checked.
1355  *
1356  * Check if a task structure is the first user space task the kernel created.
1357  *
1358  * Return: 1 if the task structure is init. 0 otherwise.
1359  */
1360 static inline int is_global_init(struct task_struct *tsk)
1361 {
1362         return task_tgid_nr(tsk) == 1;
1363 }
1364 
1365 extern struct pid *cad_pid;
1366 
1367 /*
1368  * Per process flags
1369  */
1370 #define PF_IDLE                 0x00000002      /* I am an IDLE thread */
1371 #define PF_EXITING              0x00000004      /* Getting shut down */
1372 #define PF_EXITPIDONE           0x00000008      /* PI exit done on shut down */
1373 #define PF_VCPU                 0x00000010      /* I'm a virtual CPU */
1374 #define PF_WQ_WORKER            0x00000020      /* I'm a workqueue worker */
1375 #define PF_FORKNOEXEC           0x00000040      /* Forked but didn't exec */
1376 #define PF_MCE_PROCESS          0x00000080      /* Process policy on mce errors */
1377 #define PF_SUPERPRIV            0x00000100      /* Used super-user privileges */
1378 #define PF_DUMPCORE             0x00000200      /* Dumped core */
1379 #define PF_SIGNALED             0x00000400      /* Killed by a signal */
1380 #define PF_MEMALLOC             0x00000800      /* Allocating memory */
1381 #define PF_NPROC_EXCEEDED       0x00001000      /* set_user() noticed that RLIMIT_NPROC was exceeded */
1382 #define PF_USED_MATH            0x00002000      /* If unset the fpu must be initialized before use */
1383 #define PF_USED_ASYNC           0x00004000      /* Used async_schedule*(), used by module init */
1384 #define PF_NOFREEZE             0x00008000      /* This thread should not be frozen */
1385 #define PF_FROZEN               0x00010000      /* Frozen for system suspend */
1386 #define PF_KSWAPD               0x00020000      /* I am kswapd */
1387 #define PF_MEMALLOC_NOFS        0x00040000      /* All allocation requests will inherit GFP_NOFS */
1388 #define PF_MEMALLOC_NOIO        0x00080000      /* All allocation requests will inherit GFP_NOIO */
1389 #define PF_LESS_THROTTLE        0x00100000      /* Throttle me less: I clean memory */
1390 #define PF_KTHREAD              0x00200000      /* I am a kernel thread */
1391 #define PF_RANDOMIZE            0x00400000      /* Randomize virtual address space */
1392 #define PF_SWAPWRITE            0x00800000      /* Allowed to write to swap */
1393 #define PF_NO_SETAFFINITY       0x04000000      /* Userland is not allowed to meddle with cpus_allowed */
1394 #define PF_MCE_EARLY            0x08000000      /* Early kill for mce process policy */
1395 #define PF_MUTEX_TESTER         0x20000000      /* Thread belongs to the rt mutex tester */
1396 #define PF_FREEZER_SKIP         0x40000000      /* Freezer should not count it as freezable */
1397 #define PF_SUSPEND_TASK         0x80000000      /* This thread called freeze_processes() and should not be frozen */
1398 
1399 /*
1400  * Only the _current_ task can read/write to tsk->flags, but other
1401  * tasks can access tsk->flags in readonly mode for example
1402  * with tsk_used_math (like during threaded core dumping).
1403  * There is however an exception to this rule during ptrace
1404  * or during fork: the ptracer task is allowed to write to the
1405  * child->flags of its traced child (same goes for fork, the parent
1406  * can write to the child->flags), because we're guaranteed the
1407  * child is not running and in turn not changing child->flags
1408  * at the same time the parent does it.
1409  */
1410 #define clear_stopped_child_used_math(child)    do { (child)->flags &= ~PF_USED_MATH; } while (0)
1411 #define set_stopped_child_used_math(child)      do { (child)->flags |= PF_USED_MATH; } while (0)
1412 #define clear_used_math()                       clear_stopped_child_used_math(current)
1413 #define set_used_math()                         set_stopped_child_used_math(current)
1414 
1415 #define conditional_stopped_child_used_math(condition, child) \
1416         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1417 
1418 #define conditional_used_math(condition)        conditional_stopped_child_used_math(condition, current)
1419 
1420 #define copy_to_stopped_child_used_math(child) \
1421         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1422 
1423 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1424 #define tsk_used_math(p)                        ((p)->flags & PF_USED_MATH)
1425 #define used_math()                             tsk_used_math(current)
1426 
1427 static inline bool is_percpu_thread(void)
1428 {
1429 #ifdef CONFIG_SMP
1430         return (current->flags & PF_NO_SETAFFINITY) &&
1431                 (current->nr_cpus_allowed  == 1);
1432 #else
1433         return true;
1434 #endif
1435 }
1436 
1437 /* Per-process atomic flags. */
1438 #define PFA_NO_NEW_PRIVS                0       /* May not gain new privileges. */
1439 #define PFA_SPREAD_PAGE                 1       /* Spread page cache over cpuset */
1440 #define PFA_SPREAD_SLAB                 2       /* Spread some slab caches over cpuset */
1441 #define PFA_SPEC_SSB_DISABLE            3       /* Speculative Store Bypass disabled */
1442 #define PFA_SPEC_SSB_FORCE_DISABLE      4       /* Speculative Store Bypass force disabled*/
1443 
1444 #define TASK_PFA_TEST(name, func)                                       \
1445         static inline bool task_##func(struct task_struct *p)           \
1446         { return test_bit(PFA_##name, &p->atomic_flags); }
1447 
1448 #define TASK_PFA_SET(name, func)                                        \
1449         static inline void task_set_##func(struct task_struct *p)       \
1450         { set_bit(PFA_##name, &p->atomic_flags); }
1451 
1452 #define TASK_PFA_CLEAR(name, func)                                      \
1453         static inline void task_clear_##func(struct task_struct *p)     \
1454         { clear_bit(PFA_##name, &p->atomic_flags); }
1455 
1456 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1457 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1458 
1459 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1460 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1461 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1462 
1463 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1464 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1465 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1466 
1467 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1468 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1469 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1470 
1471 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1472 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1473 
1474 static inline void
1475 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1476 {
1477         current->flags &= ~flags;
1478         current->flags |= orig_flags & flags;
1479 }
1480 
1481 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1482 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1483 #ifdef CONFIG_SMP
1484 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1485 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1486 #else
1487 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1488 {
1489 }
1490 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1491 {
1492         if (!cpumask_test_cpu(0, new_mask))
1493                 return -EINVAL;
1494         return 0;
1495 }
1496 #endif
1497 
1498 #ifndef cpu_relax_yield
1499 #define cpu_relax_yield() cpu_relax()
1500 #endif
1501 
1502 extern int yield_to(struct task_struct *p, bool preempt);
1503 extern void set_user_nice(struct task_struct *p, long nice);
1504 extern int task_prio(const struct task_struct *p);
1505 
1506 /**
1507  * task_nice - return the nice value of a given task.
1508  * @p: the task in question.
1509  *
1510  * Return: The nice value [ -20 ... 0 ... 19 ].
1511  */
1512 static inline int task_nice(const struct task_struct *p)
1513 {
1514         return PRIO_TO_NICE((p)->static_prio);
1515 }
1516 
1517 extern int can_nice(const struct task_struct *p, const int nice);
1518 extern int task_curr(const struct task_struct *p);
1519 extern int idle_cpu(int cpu);
1520 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1521 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1522 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1523 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1524 extern struct task_struct *idle_task(int cpu);
1525 
1526 /**
1527  * is_idle_task - is the specified task an idle task?
1528  * @p: the task in question.
1529  *
1530  * Return: 1 if @p is an idle task. 0 otherwise.
1531  */
1532 static inline bool is_idle_task(const struct task_struct *p)
1533 {
1534         return !!(p->flags & PF_IDLE);
1535 }
1536 
1537 extern struct task_struct *curr_task(int cpu);
1538 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1539 
1540 void yield(void);
1541 
1542 union thread_union {
1543 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1544         struct task_struct task;
1545 #endif
1546 #ifndef CONFIG_THREAD_INFO_IN_TASK
1547         struct thread_info thread_info;
1548 #endif
1549         unsigned long stack[THREAD_SIZE/sizeof(long)];
1550 };
1551 
1552 #ifndef CONFIG_THREAD_INFO_IN_TASK
1553 extern struct thread_info init_thread_info;
1554 #endif
1555 
1556 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1557 
1558 #ifdef CONFIG_THREAD_INFO_IN_TASK
1559 static inline struct thread_info *task_thread_info(struct task_struct *task)
1560 {
1561         return &task->thread_info;
1562 }
1563 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1564 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1565 #endif
1566 
1567 /*
1568  * find a task by one of its numerical ids
1569  *
1570  * find_task_by_pid_ns():
1571  *      finds a task by its pid in the specified namespace
1572  * find_task_by_vpid():
1573  *      finds a task by its virtual pid
1574  *
1575  * see also find_vpid() etc in include/linux/pid.h
1576  */
1577 
1578 extern struct task_struct *find_task_by_vpid(pid_t nr);
1579 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1580 
1581 /*
1582  * find a task by its virtual pid and get the task struct
1583  */
1584 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1585 
1586 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1587 extern int wake_up_process(struct task_struct *tsk);
1588 extern void wake_up_new_task(struct task_struct *tsk);
1589 
1590 #ifdef CONFIG_SMP
1591 extern void kick_process(struct task_struct *tsk);
1592 #else
1593 static inline void kick_process(struct task_struct *tsk) { }
1594 #endif
1595 
1596 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1597 
1598 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1599 {
1600         __set_task_comm(tsk, from, false);
1601 }
1602 
1603 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1604 #define get_task_comm(buf, tsk) ({                      \
1605         BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);     \
1606         __get_task_comm(buf, sizeof(buf), tsk);         \
1607 })
1608 
1609 #ifdef CONFIG_SMP
1610 void scheduler_ipi(void);
1611 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1612 #else
1613 static inline void scheduler_ipi(void) { }
1614 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1615 {
1616         return 1;
1617 }
1618 #endif
1619 
1620 /*
1621  * Set thread flags in other task's structures.
1622  * See asm/thread_info.h for TIF_xxxx flags available:
1623  */
1624 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1625 {
1626         set_ti_thread_flag(task_thread_info(tsk), flag);
1627 }
1628 
1629 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1630 {
1631         clear_ti_thread_flag(task_thread_info(tsk), flag);
1632 }
1633 
1634 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1635 {
1636         return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1637 }
1638 
1639 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1640 {
1641         return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1642 }
1643 
1644 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1645 {
1646         return test_ti_thread_flag(task_thread_info(tsk), flag);
1647 }
1648 
1649 static inline void set_tsk_need_resched(struct task_struct *tsk)
1650 {
1651         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1652 }
1653 
1654 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1655 {
1656         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1657 }
1658 
1659 static inline int test_tsk_need_resched(struct task_struct *tsk)
1660 {
1661         return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1662 }
1663 
1664 /*
1665  * cond_resched() and cond_resched_lock(): latency reduction via
1666  * explicit rescheduling in places that are safe. The return
1667  * value indicates whether a reschedule was done in fact.
1668  * cond_resched_lock() will drop the spinlock before scheduling,
1669  * cond_resched_softirq() will enable bhs before scheduling.
1670  */
1671 #ifndef CONFIG_PREEMPT
1672 extern int _cond_resched(void);
1673 #else
1674 static inline int _cond_resched(void) { return 0; }
1675 #endif
1676 
1677 #define cond_resched() ({                       \
1678         ___might_sleep(__FILE__, __LINE__, 0);  \
1679         _cond_resched();                        \
1680 })
1681 
1682 extern int __cond_resched_lock(spinlock_t *lock);
1683 
1684 #define cond_resched_lock(lock) ({                              \
1685         ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1686         __cond_resched_lock(lock);                              \
1687 })
1688 
1689 extern int __cond_resched_softirq(void);
1690 
1691 #define cond_resched_softirq() ({                                       \
1692         ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);     \
1693         __cond_resched_softirq();                                       \
1694 })
1695 
1696 static inline void cond_resched_rcu(void)
1697 {
1698 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1699         rcu_read_unlock();
1700         cond_resched();
1701         rcu_read_lock();
1702 #endif
1703 }
1704 
1705 /*
1706  * Does a critical section need to be broken due to another
1707  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
1708  * but a general need for low latency)
1709  */
1710 static inline int spin_needbreak(spinlock_t *lock)
1711 {
1712 #ifdef CONFIG_PREEMPT
1713         return spin_is_contended(lock);
1714 #else
1715         return 0;
1716 #endif
1717 }
1718 
1719 static __always_inline bool need_resched(void)
1720 {
1721         return unlikely(tif_need_resched());
1722 }
1723 
1724 /*
1725  * Wrappers for p->thread_info->cpu access. No-op on UP.
1726  */
1727 #ifdef CONFIG_SMP
1728 
1729 static inline unsigned int task_cpu(const struct task_struct *p)
1730 {
1731 #ifdef CONFIG_THREAD_INFO_IN_TASK
1732         return p->cpu;
1733 #else
1734         return task_thread_info(p)->cpu;
1735 #endif
1736 }
1737 
1738 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
1739 
1740 #else
1741 
1742 static inline unsigned int task_cpu(const struct task_struct *p)
1743 {
1744         return 0;
1745 }
1746 
1747 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1748 {
1749 }
1750 
1751 #endif /* CONFIG_SMP */
1752 
1753 /*
1754  * In order to reduce various lock holder preemption latencies provide an
1755  * interface to see if a vCPU is currently running or not.
1756  *
1757  * This allows us to terminate optimistic spin loops and block, analogous to
1758  * the native optimistic spin heuristic of testing if the lock owner task is
1759  * running or not.
1760  */
1761 #ifndef vcpu_is_preempted
1762 # define vcpu_is_preempted(cpu) false
1763 #endif
1764 
1765 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
1766 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
1767 
1768 #ifndef TASK_SIZE_OF
1769 #define TASK_SIZE_OF(tsk)       TASK_SIZE
1770 #endif
1771 
1772 #endif
1773 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp