Linux核心数据结构--进程或任务

struct task_struct{

/* these are hardcoded - don't touch */

volatile long        state;          /* -1 unrunnable, 0 runnable, >0 stopped */

  long                 counter;

  long                 priority;

  unsigned             long signal;

  unsigned             long blocked;   /* bitmap of masked signals */

unsigned             long flags;     /* per process flags, defined below */

int errno;

  long                 debugreg[8];    /* Hardware debugging registers */

  struct exec_domain   *exec_domain;

/* various fields */

struct linux_binfmt  *binfmt;

struct task_struct   *next_task, *prev_task;

struct task_struct   *next_run,  *prev_run;

unsigned long        saved_kernel_stack;

unsigned long        kernel_stack_page;

  int                  exit_code, exit_signal;

  /* ??? 这里的注释不知道是什么？*/

  unsigned long        personality;

  int                  dumpable:1;

  int                  did_exec:1;

int                  pid;

  int                  pgrp;

int                  tty_old_pgrp;

int                  session;

  /* boolean value for session group leader */

  int                  leader;

  int                  groups[NGROUPS];

  /*

   * pointers to (original) parent process, youngest child, younger sibling,

   * older sibling, respectively.  (p->father can be replaced with

   * p->p_pptr->pid)

   */

  struct task_struct   *p_opptr, *p_pptr, *p_cptr,

                       *p_ysptr, *p_osptr;

  struct wait_queue    *wait_chldexit; 

  unsigned short       uid,euid,suid,fsuid;

  unsigned short       gid,egid,sgid,fsgid;

  unsigned long        timeout, policy, rt_priority;

  unsigned long        it_real_value, it_prof_value, it_virt_value;

  unsigned long        it_real_incr, it_prof_incr, it_virt_incr;

  struct timer_list    real_timer;

  long                 utime, stime, cutime, cstime, start_time;

/* mm fault and swap info: this can arguably be seen as either

   mm-specific or thread-specific */

  unsigned long        min_flt, maj_flt, nswap, cmin_flt, cmaj_flt, cnswap;

  int swappable:1;

  unsigned long        swap_address;

  unsigned long        old_maj_flt;    /* old value of maj_flt */

unsigned long        dec_flt;        /* page fault count of the last time */

  unsigned long        swap_cnt;       /* number of pages to swap on next pass */

/* limits */

  struct rlimit        rlim[RLIM_NLIMITS];

  unsigned short       used_math;

  char                 comm[16];

/* file system info */

  int                  link_count;

  struct tty_struct    *tty;           /* NULL if no tty */

/* ipc stuff */

struct sem_undo      *semundo;

  struct sem_queue     *semsleeping;

/* ldt for this task - used by Wine.  If NULL, default_ldt is used */

struct desc_struct *ldt;

/* tss for this task */

struct thread_struct tss;

/* filesystem information */

struct fs_struct     *fs;

/* open file information */

  struct files_struct  *files;

/* memory management info */

  struct mm_struct     *mm;

/* signal handlers */

struct signal_struct *sig;

#ifdef __SMP__

  int                  processor;

  int                  last_processor;

  int                  lock_depth;     /* Lock depth.

                                          We can context switch in and out

                                          of holding a syscall kernel lock... */ 

#endif  

};