结构体 taskstats¶
本文档包含对结构体 taskstats 字段的解释。
结构体 taskstats 中有三个不同的字段组
- 通用和基本帐户字段
如果设置了 CONFIG_TASKSTATS，则启用 taskstats 接口，并在任务的 do_exit() 时收集通用字段和基本帐户字段以进行传递。
- 延迟帐户字段
这些字段位于
/* Delay accounting fields start */
和
/* Delay accounting fields end */
如果设置了 CONFIG_TASK_DELAY_ACCT，则收集它们的值。
- 扩展帐户字段
这些字段位于
/* Extended accounting fields start */
和
/* Extended accounting fields end */
如果设置了 CONFIG_TASK_XACCT，则收集它们的值。
每个任务和每个线程的上下文切换计数统计信息
SMT 机器的时间帐户
用于内存回收的扩展延迟帐户字段
未来的扩展应将字段添加到 taskstats 结构的末尾，并且不应更改结构中每个字段的相对位置。
struct taskstats {
通用和基本帐户字段
/* The version number of this struct. This field is always set to * TAKSTATS_VERSION, which is defined in <linux/taskstats.h>. * Each time the struct is changed, the value should be incremented. */ __u16 version; /* The exit code of a task. */ __u32 ac_exitcode; /* Exit status */ /* The accounting flags of a task as defined in <linux/acct.h> * Defined values are AFORK, ASU, ACOMPAT, ACORE, and AXSIG. */ __u8 ac_flag; /* Record flags */ /* The value of task_nice() of a task. */ __u8 ac_nice; /* task_nice */ /* The name of the command that started this task. */ char ac_comm[TS_COMM_LEN]; /* Command name */ /* The scheduling discipline as set in task->policy field. */ __u8 ac_sched; /* Scheduling discipline */ __u8 ac_pad[3]; __u32 ac_uid; /* User ID */ __u32 ac_gid; /* Group ID */ __u32 ac_pid; /* Process ID */ __u32 ac_ppid; /* Parent process ID */ /* The time when a task begins, in [secs] since 1970. */ __u32 ac_btime; /* Begin time [sec since 1970] */ /* The elapsed time of a task, in [usec]. */ __u64 ac_etime; /* Elapsed time [usec] */ /* The user CPU time of a task, in [usec]. */ __u64 ac_utime; /* User CPU time [usec] */ /* The system CPU time of a task, in [usec]. */ __u64 ac_stime; /* System CPU time [usec] */ /* The minor page fault count of a task, as set in task->min_flt. */ __u64 ac_minflt; /* Minor Page Fault Count */ /* The major page fault count of a task, as set in task->maj_flt. */ __u64 ac_majflt; /* Major Page Fault Count */
延迟帐户字段
/* Delay accounting fields start * * All values, until the comment "Delay accounting fields end" are * available only if delay accounting is enabled, even though the last * few fields are not delays * * xxx_count is the number of delay values recorded * xxx_delay_total is the corresponding cumulative delay in nanoseconds * * xxx_delay_total wraps around to zero on overflow * xxx_count incremented regardless of overflow */ /* Delay waiting for cpu, while runnable * count, delay_total NOT updated atomically */ __u64 cpu_count; __u64 cpu_delay_total; /* Following four fields atomically updated using task->delays->lock */ /* Delay waiting for synchronous block I/O to complete * does not account for delays in I/O submission */ __u64 blkio_count; __u64 blkio_delay_total; /* Delay waiting for page fault I/O (swap in only) */ __u64 swapin_count; __u64 swapin_delay_total; /* cpu "wall-clock" running time * On some architectures, value will adjust for cpu time stolen * from the kernel in involuntary waits due to virtualization. * Value is cumulative, in nanoseconds, without a corresponding count * and wraps around to zero silently on overflow */ __u64 cpu_run_real_total; /* cpu "virtual" running time * Uses time intervals seen by the kernel i.e. no adjustment * for kernel's involuntary waits due to virtualization. * Value is cumulative, in nanoseconds, without a corresponding count * and wraps around to zero silently on overflow */ __u64 cpu_run_virtual_total; /* Delay accounting fields end */ /* version 1 ends here */
扩展帐户字段
/* Extended accounting fields start */ /* Accumulated RSS usage in duration of a task, in MBytes-usecs. * The current rss usage is added to this counter every time * a tick is charged to a task's system time. So, at the end we * will have memory usage multiplied by system time. Thus an * average usage per system time unit can be calculated. */ __u64 coremem; /* accumulated RSS usage in MB-usec */ /* Accumulated virtual memory usage in duration of a task. * Same as acct_rss_mem1 above except that we keep track of VM usage. */ __u64 virtmem; /* accumulated VM usage in MB-usec */ /* High watermark of RSS usage in duration of a task, in KBytes. */ __u64 hiwater_rss; /* High-watermark of RSS usage */ /* High watermark of VM usage in duration of a task, in KBytes. */ __u64 hiwater_vm; /* High-water virtual memory usage */ /* The following four fields are I/O statistics of a task. */ __u64 read_char; /* bytes read */ __u64 write_char; /* bytes written */ __u64 read_syscalls; /* read syscalls */ __u64 write_syscalls; /* write syscalls */ /* Extended accounting fields end */
每个任务和每个线程的统计信息
__u64 nvcsw; /* Context voluntary switch counter */ __u64 nivcsw; /* Context involuntary switch counter */
SMT 机器的时间帐户
__u64 ac_utimescaled; /* utime scaled on frequency etc */ __u64 ac_stimescaled; /* stime scaled on frequency etc */ __u64 cpu_scaled_run_real_total; /* scaled cpu_run_real_total */
用于内存回收的扩展延迟帐户字段
/* Delay waiting for memory reclaim */ __u64 freepages_count; __u64 freepages_delay_total;
}