linux进程控制块

linux进程控制块 struct task_struct { /* * offsets of these are hardcoded elsewhere - touch with care */ volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */ //进程当前的状态 unsigned long flags; /* per process flags, defined below */ //反应进程状态的信息，但不 是运行状态，定义见下 int sigpending; //进程收到了信号，但尚未处理 mm_segment_t addr_limit; /* thread address space: //虚存地址上限 0-0xBFFFFFFF for user-thead 0-0xFFFFFFFF for kernel-thread */ struct exec_domain *exec_domain; volatile long need_resched; //与进程调度有关 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 示用户从系统空间按返回用户空间要执 行的一次调度 unsigned long ptrace; int lock_depth; /* Lock depth */ /* * offset 32 begins here on 32-bit platforms. We keep * all fields in a single cacheline that are needed for * the goodness() loop in schedule(). */ long counter; //与进程调度相关 long nice; unsigned long policy; //实用于本进程的调度政策 struct mm_struct *mm; int processor; /* * cpus_runnable is ~0 if the process is not running on any * CPU. It's (1 << cpu) if it's running on a CPU. This mask * is updated under the runqueue lock. * * To determine whether a process might run on a CPU, this * mask is AND-ed with cpus_allowed. */ unsigned long cpus_runnable, cpus_allowed; /* * (only the 'next' pointer fits into the cacheline, but * that's just fine.) */ struct list_head run_list; unsigned long sleep_time; struct task_struct *next_task, *prev_task; //内核会对每一个进程做点什么事情的时候，常常 需要将其连成一个队列，这2个指针用于这个目的 struct mm_struct *active_mm; struct list_head local_pages; unsigned int allocation_order, nr_local_pages; /* task state */ struct linux_binfmt *binfmt;//应用文件 格式 pdf格式笔记格式下载页码格式下载公文格式下载简报格式下载 int exit_code, exit_signal; int pdeath_signal; /* The signal sent when the parent dies */ /* ??? */ unsigned long personality; //进程的个性化信息，详细见下 int did_exec:1; unsigned task_dumpable:1; pid_t pid; //进程号 pid_t pgrp; pid_t tty_old_pgrp; pid_t session; pid_t tgid; /* boolean value for session group leader */ int leader; /* * pointers to (original) parent process, youngest child, younger sibling, * older sibling, respectively. (p->father can be replaced with * p->p_ ppt 关于艾滋病ppt课件精益管理ppt下载地图下载ppt可编辑假如ppt教学课件下载triz基础知识ppt r->pid) */ struct task_struct *p_opptr, *p_pptr, *p_cptr, *p_ysptr, *p_osptr; //用于族谱信息的，例如 p_opptr指向父进程 struct list_head thread_group; /* PID hash table linkage. */ struct task_struct *pidhash_next; struct task_struct **pidhash_pprev; //pid是随机分配的，我们常常使用kill pid想进程发送 信号(大部分人认为是杀死进程，其实这是个发送信号的指令，默认的参数为杀死。如果想 暂停某进程，只需kill STOP 进程的PID)，这里可以看到根据pid寻找进程的操作是经常被 使用的，而pid又是随机分配，于是这里边用这2个指针指向一个杂凑数组，数组是按照杂 凑的算法，以pid为关键字建立，方便根据pid来寻找task_struct wait_queue_head_t wait_chldexit; /* for wait4() */ struct completion *vfork_done; /* for vfork() */ unsigned long rt_priority; //优先级 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; struct tms times; //运行时间的总汇 unsigned long start_time; long per_cpu_utime[NR_CPUS], per_cpu_stime[NR_CPUS]; //在多个处理器上运行于系统空间和用户空间的时间 /* 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;//发生页面异常的次数和换入换出的次数 int swappable:1; /* process credentials */ uid_t uid,euid,suid,fsuid; gid_t gid,egid,sgid,fsgid; //与文件权限有关的 int ngroups; gid_t groups[NGROUPS]; kernel_cap_t cap_effective, cap_inheritable, cap_permitted; //权限，比如该进程是否有权限从新引导系统，这里是大概介绍 int keep_capabilities:1; struct user_struct *user; //指向该进程拥有的用户 /* limits */ struct rlimit rlim[RLIM_NLIMITS]; //进程对各种资源使用数量的限制，详细见下 unsigned short used_math; char comm[16]; /* file system info */ int link_count, total_link_count; struct tty_struct *tty; /* NULL if no tty */ unsigned int locks; /* How many file locks are being held */ /* ipc stuff */ struct sem_undo *semundo; struct sem_queue *semsleeping; /* CPU-specific state of this task */ struct thread_struct thread; /* filesystem information */ struct fs_struct *fs; /* open file information */ struct files_struct *files; /* namespace */ struct namespace *namespace; /* signal handlers */ spinlock_t sigmask_lock; /* Protects signal and blocked */ struct signal_struct *sig; sigset_t blocked; struct sigpending pending; unsigned long sas_ss_sp; size_t sas_ss_size; int (*notifier)(void *priv); void *notifier_data; sigset_t *notifier_mask; /* Thread group tracking */ u32 parent_exec_id; u32 self_exec_id; /* Protection of (de-)allocation: mm, files, fs, tty */ spinlock_t alloc_lock; /* journalling filesystem info */ void *journal_info; };