LINUX 内核之 (第十四章)
第14章 Linux数据结构
--------------------------------------------------------------------------------
该附录描述了Linux使用的主要数据结构。 block_dev_struct block_dev_struct 数据结构用来登记块设备以被缓冲区使用。这些结构被存放在blk_dev vector中。
struct blk_dev_struct {
void (*request_fn)(void);
struct request * current_request;
struct request plug;
struct tq_struct plug_tq;
};
buffer_head The buffer_head 数据结构用来存放缓冲区中的一个数据块的信息。 /* bh state bits */
#define BH_Uptodate 0 /* 1 if the buffer contains valide data*/ #define BH_Dirty 1 /* 1 if the buffer is dirty */
#define BH_Lock 2 /* 1 if the buffer is locked */
#define BH_Req 3 /* 0 if the buffer has been invalidated */ #define BH_Touched 4 /* 1 if the buffer has been touched (aging) */ #define BH_Has_aged 5 /* 1 if the buffer has been aged (aging) */
#define BH_Protected 6 /* 1 if the buffer is protected */ #define BH_FreeOnIO 7 /* 1 to discard the buffer_head after IO */
struct buffer_head { /* First cache line: */
unsigned long b_blocknr; /* block number */ kdev_t b_dev; /* device (B_FREE = free) */ kdev_t b_rdev; /* Real device */ unsigned long b_rsector; /* Real buffer location on disk */
struct buffer_head *b_next; /* Hash queue list */ struct buffer_head *b_this_page; /* circular list of buffers in one page */ /* Second cache line: */
unsigned long b_state; /* buffer state bitmap (above) */
struct buffer_head *b_next_free;
unsigned int b_count; /* users using this block */
unsigned long b_size; /* block size */ /*
Non-performance-critical data follows. */ char *b_data; /* pointer to data block */
unsigned int b_list; /* List that this buffer appears */ unsigned long b_flushtime; /* Time when this (dirty) buffer * should be written */
unsigned long b_lru_time; /* Time when this buffer was * last used. */
struct wait_queue *b_wait; struct buffer_head *b_prev; /* doubly linked hash list */
struct buffer_head *b_prev_free; /* doubly linked list of buffers */ struct buffer_head *b_reqnext; /* request queue */ };
device 系统中每一个网络设备都对应于一个设备数据结构。
struct device { /* * This is the first field of the \"visible\" part of this structure * (i.e. as seen by users in the \"Space.c\" file). It is the name * the interface. */ char *name; /* I/O specific fields */ unsigned long rmem_end; /* shmem \"recv\" end */ unsigned long rmem_start; /* shmem \"recv\" start */ unsigned long mem_end; /* shared mem end */ unsigned long mem_start; /* shared mem start */ unsigned long base_addr; /* device I/O address */ unsigned char irq; /* device IRQ number */ /* Low-level status flags. */ volatile unsigned char start, /* start an operation */ interrupt; /* interrupt arrived */ unsigned long tbusy; /* transmitter busy */ struct device *next; /* The device initialization function. Called only once. */ int (*init)(struct device *dev); /* Some hardware also needs these fields, but they are not part of the usual set specified in Space.c. */ unsigned char if_port; /* Selectable AUI,TP, */ unsigned char dma; /* DMA channel */ struct enet_statistics* (*get_stats)(struct device *dev); /* * This marks the end of the \"visible\" part of the structure. All * fields hereafter are internal to the system, and may change at * will (read: may be cleaned up at will). */ /* These may be needed for future network-power-down code. */ unsigned long trans_start; /* Time (jiffies) of last transmit */ unsigned long last_rx; /* Time of last Rx */ unsigned short flags; /* interface flags (BSD)*/ unsigned short family; /* address family ID */ unsigned short metric; /* routing metric */ unsigned short mtu; /* MTU value */ unsigned short type; /* hardware type */ unsigned short hard_header_len; /* hardware hdr len */ void *priv; /* private data */ /* Interface address info. */ unsigned char broadcast[MAX_ADDR_LEN]; unsigned char pad; unsigned char dev_addr[MAX_ADDR_LEN]; unsigned char addr_len; /* hardware addr len */ unsigned long pa_addr; /* protocol address */ unsigned long pa_brdaddr; /* protocol broadcast addr*/ unsigned long pa_dstaddr; /* protocol P-P other addr*/ unsigned long pa_mask; /* protocol netmask */ unsigned short pa_alen; /* protocol address len */ struct dev_mc_list *mc_list; /* M\"cast mac addrs */ int mc_count; /* No installed mcasts */ struct ip_mc_list *ip_mc_list; /* IP m\"cast filter chain */ __u32 tx_queue_len; /* Max frames per queue */ /* For load balancing driver pair support */ unsigned long pkt_queue; /* Packets queued */ struct device *slave; /* Slave device */ struct net_alias_info *alias_info; /* main dev alias info */ struct net_alias *my_alias; /* alias devs */ /* Pointer to the interface buffers. */ struct sk_buff_head buffs[DEV_NUMBUFFS]; /* Pointers to interface service routines. */ int (*open)(struct device *dev); int (*stop)(struct device *dev); int (*hard_start_xmit) (struct sk_buff *skb, struct device *dev); int (*hard_header) (struct sk_buff *skb, struct device *dev, unsigned short type, void *daddr, void *saddr, unsigned len); int (*rebuild_header)(void *eth, struct device *dev, unsigned long raddr, struct sk_buff *skb); void (*set_multicast_list)(struct device *dev); int (*set_mac_address)(struct device *dev, void *addr); int (*do_ioctl)(struct device *dev, struct ifreq *ifr, int cmd); int (*set_config)(struct device *dev, struct ifmap *map); void (*header_cache_bind)(struct hh_cache **hhp, struct device *dev, unsigned short htype, __u32 daddr); void (*header_cache_update)(struct hh_cache *hh, struct device *dev, unsigned char * haddr); int (*change_mtu)(struct device *dev, int new_mtu); struct iw_statistics* (*get_wireless_stats)(struct device *dev); }; device_struct device_struct 数据结构用来登记字符和块设备(含有相应的名字和对此设备的文件操作集)。每一个chrdevs and blkdevs向量的入口对应一个字符或块设备。 struct device_struct { const char * name; struct file_operations * fops; }; file 每个打开的文件， socket 接口都对应一个文件数据结构。 struct file { mode_t f_mode; loff_t f_pos; unsigned short f_flags; unsigned short f_count; unsigned long f_reada, f_ramax, f_raend, f_ralen, f_rawin; struct file *f_next, *f_prev; int f_owner; /* pid or -pgrp where SIGIO should be sent */ struct inode * f_inode; struct file_operations * f_op; unsigned long f_version; void *private_data; /* needed for tty driver, and maybe others */ }; files_struct files_struct 数据结构描述一个正被打开的文件。 struct files_struct { int count; fd_set close_on_exec; fd_set open_fds; struct file * fd[NR_OPEN]; }; fs_struct struct fs_struct { int count; unsigned short umask; struct inode * root, * pwd; }; gendisk gendisk 数据结构含有一个硬盘的信息。当系统初始化，发现硬盘和检测分区参数时，此结构被填充。 struct hd_struct { long start_sect; long nr_sects; }; struct gendisk { int major; /* major number of driver */ const char *major_name; /* name of major driver */ int minor_shift; /* number of times minor is shifted to get real minor */ int max_p; /* maximum partitions per device */ int max_nr; /* maximum number of real devices */ void (*init)(struct gendisk *); /* Initialization called before we do our thing */ struct hd_struct *part; /* partition table */ int *sizes; /* device size in blocks, copied to blk_size[] */ int nr_real; /* number of real devices */ void *real_devices; /* internal use */ struct gendisk *next; }; inode VFS inode 数据结构包含一个磁盘中的文件或目录的信息。(译者注：从逻辑概念 “文件到物理上的”数据块“映射。) struct inode { kdev_t i_dev; unsigned long i_ino; umode_t i_mode; nlink_t i_nlink; uid_t i_uid; gid_t i_gid; kdev_t i_rdev; off_t i_size; time_t i_atime; time_t i_mtime; time_t i_ctime; unsigned long i_blksize; unsigned long i_blocks; unsigned long i_version; unsigned long i_nrpages; struct semaphore i_sem; struct inode_operations *i_op; struct super_block *i_sb; struct wait_queue *i_wait; struct file_lock *i_flock; struct vm_area_struct *i_mmap; struct page *i_pages; struct dquot *i_dquot[MAXQUOTAS]; struct inode *i_next, *i_prev; struct inode *i_hash_next, *i_hash_prev; struct inode *i_bound_to, *i_bound_by; struct inode *i_mount; unsigned short i_count; unsigned short i_flags; unsigned char i_lock; unsigned char i_dirt; unsigned char i_pipe; unsigned char i_sock; unsigned char i_seek; unsigned char i_update; unsigned short i_writecount; union { struct pipe_inode_info pipe_i; struct minix_inode_info minix_i; struct ext_inode_info ext_i; struct ext2_inode_info ext2_i; struct hpfs_inode_info hpfs_i; struct msdos_inode_info msdos_i; struct umsdos_inode_info umsdos_i; struct iso_inode_info isofs_i; struct nfs_inode_info nfs_i; struct xiafs_inode_info xiafs_i; struct sysv_inode_info sysv_i; struct affs_inode_info affs_i; struct ufs_inode_info ufs_i; struct socket socket_i; void *generic_ip; } u; }; ipc_perm ipc_perm 结构描述了一个 System V IPC 对象的存取权限。. struct ipc_perm { key_t key; ushort uid; /* owner euid and egid */ ushort gid; ushort cuid; /* creator euid and egid */ ushort cgid; ushort mode; /* access modes see mode flags below */ ushort seq; /* sequence number */ }; irqaction irqaction 结构用来描述系统的中断句柄。 struct irqaction { void (*handler)(int, void *, struct pt_regs *); unsigned long flags; unsigned long mask; const char *name; void *dev_id; struct irqaction *next; }; linux_binfmt 每个Linux 可以理解的二进制文件格式对应一个linux_binfmt 数据结构。 struct linux_binfmt { struct linux_binfmt * next; long *use_count; int (*load_binary)(struct linux_binprm *, struct pt_regs * regs); int (*load_shlib)(int fd); int (*core_dump)(long signr, struct pt_regs * regs); }; mem_map_t mem_map_t 数据结构(或叫做页面) 用来存放每个物理内存页面的信息。 typedef struct page { /* these must be first (free area handling) */ struct page *next; struct page *prev; struct inode *inode; unsigned long offset; struct page *next_hash; atomic_t count; unsigned flags; /* atomic flags, some possibly updated asynchronously */ unsigned dirty:16, age:8; struct wait_queue *wait; struct page *prev_hash; struct buffer_head *buffers; unsigned long swap_unlock_entry; unsigned long map_nr; /* page->map_nr == page - mem_map */ } mem_map_t; mm_struct mm_struct 用来描述一个任务活一个进程的虚拟内存空间。 struct mm_struct { int count; pgd_t * pgd; unsigned long context; unsigned long start_code, end_code, start_data, end_data; unsigned long start_brk, brk, start_stack, start_mmap; unsigned long arg_start, arg_end, env_start, env_end; unsigned long rss, total_vm, locked_vm; unsigned long def_flags; struct vm_area_struct * mmap; struct vm_area_struct * mmap_avl; struct semaphore mmap_sem; }; pci_bus 系统中的每个PCI总线对应一个 pci_bus 结构。 struct pci_bus { struct pci_bus *parent; /* parent bus this bridge is on */ struct pci_bus *children; /* chain of P2P bridges on this bus */ struct pci_bus *next; /* chain of all PCI buses */ struct pci_dev *self; /* bridge device as seen by parent */ struct pci_dev *devices; /* devices behind this bridge */ void *sysdata; /* hook for sys-specific extension */ unsigned char number; /* bus number */ unsigned char primary; /* number of primary bridge */ unsigned char secondary; /* number of secondary bridge */ unsigned char subordinate; /* max number of subordinate buses */ }; pci_dev 系统中的每个PCI 设备，包括PCI-PCI和PCI-ISA桥设备都分别对应于一个 pci_dev 结构。 /* * There is one pci_dev structure for each slot-number/function-number * combination: */ struct pci_dev { struct pci_bus *bus; /* bus this device is on */ struct pci_dev *sibling; /* next device on this bus */ struct pci_dev *next; /* chain of all devices */ void *sysdata; /* hook for sys-specific extension */ unsigned int devfn; /* encoded device & function index */ unsigned short vendor; unsigned short device; unsigned int class; /* 3 bytes: (base,sub,prog-if) */ unsigned int master : 1; /* set if device is master capable */ /* * In theory, the irq level can be read from configuration * space and all would be fine. However, old PCI chips don\"t * support these registers and return 0 instead. For example, * the Vision864-P rev 0 chip can uses INTA, but returns 0 in * the interrupt line and pin registers. pci_init() * initializes this field with the value at PCI_INTERRUPT_LINE * and it is the job of pcibios_fixup() to change it if * necessary. The field must not be 0 unless the device * cannot generate interrupts at all. */ unsigned char irq; /* irq generated by this device */ }; request request 结构用来向系统中的块设备发出请求。 这些请求是关于读或写缓冲区中的数据块。 struct request { volatile int rq_status; #define RQ_INACTIVE (-1) #define RQ_ACTIVE 1 #define RQ_SCSI_BUSY 0xffff #define RQ_SCSI_DONE 0xfffe #define RQ_SCSI_DISCONNECTING 0xffe0 kdev_t rq_dev; int cmd; /* READ or WRITE */ int errors; unsigned long sector; unsigned long nr_sectors; unsigned long current_nr_sectors; char * buffer; struct semaphore * sem; struct buffer_head * bh; struct buffer_head * bhtail; struct request * next; }; rtable 每个 rtable 结构含有对应一个IP主机的路由信息。rtable 结构在IP路由缓冲中被使用。 struct rtable { struct rtable *rt_next; __u32 rt_dst; __u32 rt_src; __u32 rt_gateway; atomic_t rt_refcnt; atomic_t rt_use; unsigned long rt_window; atomic_t rt_lastuse; struct hh_cache *rt_hh; struct device *rt_dev; unsigned short rt_flags; unsigned short rt_mtu; unsigned short rt_irtt; unsigned char rt_tos; }; semaphore Semaphores 被用来保护临界数据和临界区代码。 struct semaphore { int count; int waking; int lock ; /* to make waking testing atomic */ struct wait_queue *wait; }; sk_buff sk_buff 结构被用来当数据在网络协议之间移动时描述网络数据。 struct sk_buff { struct sk_buff *next; /* Next buffer in list*/ struct sk_buff *prev; /* Previous buffer in list*/ struct sk_buff_head *list; /* List we are on */ int magic_debug_cookie; struct sk_buff *link3; /* Link for IP protocol level buffer chains */ struct sock *sk; /* Socket we are owned by */ unsigned long when; /* used to compute rtt\"s */ struct timeval stamp; /* Time we arrived */ struct device *dev; /* Device we arrived on/are leaving by */ union { struct tcphdr *th; struct ethhdr *eth; struct iphdr *iph; struct udphdr *uh; unsigned char *raw; /* for passing file handles in a unix domain socket */ void *filp; } h; union { /* As yet incomplete physical layer views */ unsigned char *raw; struct ethhdr *ethernet; } mac; struct iphdr *ip_hdr; /* For IPPROTO_RAW */ unsigned long len; /* Length of actual data */ unsigned long csum; /* Checksum */ __u32 saddr; /* IP source address */ __u32 daddr; /* IP target address */ __u32 raddr; /* IP next hop address */ __u32 seq; /* TCP sequence number */ __u32 end_seq; /* seq [+ fin] [+ syn] + datalen */ __u32 ack_seq; /* TCP ack sequence number */ unsigned char proto_priv[16]; volatile char acked, /* Are we acked ? */ used, /* Are we in use ? */ free, /* How to free this buffer */ arp; /* Has IP/ARP resolution finished */ unsigned char tries, /* Times tried */ lock, /* Are we locked ? */ localroute, /* Local routing asserted for this frame */ pkt_type, /* Packet class */ pkt_bridged, /* Tracker for bridging */ ip_summed; /* Driver fed us an IP checksum */ #define PACKET_HOST 0 /* To us */ #define PACKET_BROADCAST 1 /* To all */ #define PACKET_MULTICAST 2 /* To group */ #define PACKET_OTHERHOST 3 /* To someone else */ unsigned short users; /* User count - see datagram.c,tcp.c */ unsigned short protocol; /* Packet protocol from driver. */ unsigned int truesize; /* Buffer size */ atomic_t count; /* reference count */ struct sk_buff *data_skb; /* Link to the actual data skb */ unsigned char *head; /* Head of buffer */ unsigned char *data; /* Data head pointer */ unsigned char *tail; /* Tail pointer */ unsigned char *end; /* End pointer */ void (*destructor)(struct sk_buff *); /* Destruct function */ __u16 redirport; /* Redirect port */ }; sock 每个sock 数据结构维护一个关于BSD socket 的协议信息。例如，对一个INET类型的socket，此数据结构将含有所有TCP/IP和UDP/IP的相关信息。 struct sock { /* This must be first. */ struct sock *sklist_next; struct sock *sklist_prev; struct options *opt; atomic_t wmem_alloc; atomic_t rmem_alloc; unsigned long allocation; /* Allocation mode */ __u32 write_seq; __u32 sent_seq; __u32 acked_seq; __u32 copied_seq; __u32 rcv_ack_seq; unsigned short rcv_ack_cnt; /* count of same ack */ __u32 window_seq; __u32 fin_seq; __u32 urg_seq; __u32 urg_data; __u32 syn_seq; int users; /* user count */ /* * Not all are volatile, but some are, so we * might as well say they all are. */ volatile char dead, urginline, intr, blog, done, reuse, keepopen, linger, delay_acks, destroy, ack_timed, no_check, zapped, broadcast, nonagle, bsdism; unsigned long lingertime; int proc; struct sock *next; struct sock **pprev; struct sock *bind_next; struct sock **bind_pprev; struct sock *pair; int hashent; struct sock *prev; struct sk_buff *volatile send_head; struct sk_buff *volatile send_next; struct sk_buff *volatile send_tail; struct sk_buff_head back_log; struct sk_buff *partial; struct timer_list partial_timer; long retransmits; struct sk_buff_head write_queue, receive_queue; struct proto *prot; struct wait_queue **sleep; __u32 daddr; __u32 saddr; /* Sending source */ __u32 rcv_saddr; /* Bound address */ unsigned short max_unacked; unsigned short window; __u32 lastwin_seq; /* sequence number when we last updated the window we offer */ __u32 high_seq; /* sequence number when we did current fast retransmit */ volatile unsigned long ato; /* ack timeout */ volatile unsigned long lrcvtime; /* jiffies at last data rcv */ volatile unsigned long idletime; /* jiffies at last rcv */ unsigned int bytes_rcv; /* * mss is min(mtu, max_window) */ unsigned short mtu; /* mss negotiated in the syn\"s */ volatile unsigned short mss; /* current eff. mss - can change */ volatile unsigned short user_mss; /* mss requested by user in ioctl */ volatile unsigned short max_window; unsigned long window_clamp; unsigned int ssthresh; unsigned short num; volatile unsigned short cong_window; volatile unsigned short cong_count; volatile unsigned short packets_out; volatile unsigned short shutdown; volatile unsigned long rtt; volatile unsigned long mdev; volatile unsigned long rto; volatile unsigned short backoff; int err, err_soft; /* Soft holds errors that don\"t cause failure but are the cause of a persistent failure not just \"timed out\" */ unsigned char protocol; volatile unsigned char state; unsigned char ack_backlog; unsigned char max_ack_backlog; unsigned char priority; unsigned char debug; int rcvbuf; int sndbuf; unsigned short type; unsigned char localroute; /* Route locally only */ /* * This is where all the private (optional) areas that don\"t * overlap will eventually live. */ union { struct unix_opt af_unix; #if defined(CONFIG_ATALK) || defined(CONFIG_ATALK_MODULE) struct atalk_sock af_at; #endif #if defined(CONFIG_IPX) || defined(CONFIG_IPX_MODULE) struct ipx_opt af_ipx; #endif #ifdef CONFIG_INET struct inet_packet_opt af_packet; #ifdef CONFIG_NUTCP struct tcp_opt af_tcp; #endif #endif } protinfo; /* * IP \"private area\" */ int ip_ttl; /* TTL setting */ int ip_tos; /* TOS */ struct tcphdr dummy_th; struct timer_list keepalive_timer; /* TCP keepalive hack */ struct timer_list retransmit_timer; /* TCP retransmit timer */ struct timer_list delack_timer; /* TCP delayed ack timer */ int ip_xmit_timeout; /* Why the timeout is running */ struct rtable *ip_route_cache; /* Cached output route */ unsigned char ip_hdrincl; /* Include headers ? */ #ifdef CONFIG_IP_MULTICAST int ip_mc_ttl; /* Multicasting TTL */ int ip_mc_loop; /* Loopback */ char ip_mc_name[MAX_ADDR_LEN]; /* Multicast device name */ struct ip_mc_socklist *ip_mc_list; /* Group array */ #endif /* * This part is used for the timeout functions (timer.c). */ int timeout; /* What are we waiting for? */ struct timer_list timer; /* This is the TIME_WAIT/receive * timer when we are doing IP */ struct timeval stamp; /* * Identd */ struct socket *socket; /* * Callbacks */ void (*state_change)(struct sock *sk); void (*data_ready)(struct sock *sk,int bytes); void (*write_space)(struct sock *sk); void (*error_report)(struct sock *sk); }; socket 每个 socket 结构包含一个BSD socket 信息。这个结构不是独立存在的，而是作为一个VFS数据结构的一个部份。 struct socket { short type; /* SOCK_STREAM, ... */ socket_state state; long flags; struct proto_ops *ops; /* protocols do most everything */ void *data; /* protocol data */ struct socket *conn; /* server socket connected to */ struct socket *iconn; /* incomplete client conn.s */ struct socket *next; struct wait_queue **wait; /* ptr to place to wait on */ struct inode *inode; struct fasync_struct *fasync_list; /* Asynchronous wake up list */ struct file *file; /* File back pointer for gc */ }; task_struct 每个 task_struct 数据结构描述系统中的进程或任务。 (译者注：请注意结构中已考虑SMP的结构) 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; /* ??? */ 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 }; timer_list timer_list 结构用来实现对进程的定时器的操作。 struct timer_list { struct timer_list *next; struct timer_list *prev; unsigned long expires; unsigned long data; void (*function)(unsigned long); }; tq_struct 每个任务队列 task queue (tq_struct) 含有已在排队的任务信息。一般来说，这些任务是设备驱动程序所需的，但不是必须“立刻”被完成。(译者注：千万注意，这个队列不是进程调度队列，而是一个函数(如设备驱动程序调用的一些核心函数)队列。结构中含有函数指针和被传递的参数。请回忆递归时栈结构中的内容。不同的是队列是FIFO，而栈是LIFO) struct tq_struct { struct tq_struct *next; /* linked list of active bh\"s */ int sync; /* must be initialized to zero */ void (*routine)(void *); /* function to call */ void *data; /* argument to function */ }; vm_area_struct 每个 vm_area_struct 结构含有一个进程虚拟内存的每个部份的描述。 struct vm_area_struct { struct mm_struct * vm_mm; /* VM area parameters */ unsigned long vm_start; unsigned long vm_end; pgprot_t vm_page_prot; unsigned short vm_flags; /* AVL tree of VM areas per task, sorted by address */ short vm_avl_height; struct vm_area_struct * vm_avl_left; struct vm_area_struct * vm_avl_right; /* linked list of VM areas per task, sorted by address */ struct vm_area_struct * vm_next; /* for areas with inode, the circular list inode->i_mmap */ /* for shm areas, the circular list of attaches */ /* otherwise unused */ struct vm_area_struct * vm_next_share; struct vm_area_struct * vm_prev_share; /* more */ struct vm_operations_struct * vm_ops; unsigned long vm_offset; struct inode * vm_inode; unsigned long vm_pte; /* shared mem */ };发布人:netbull 来自:Linuxeden