1The struct taskstats 2-------------------- 3 4This document contains an explanation of the struct taskstats fields. 5 6There are three different groups of fields in the struct taskstats: 7 81) Common and basic accounting fields 9 If CONFIG_TASKSTATS is set, the taskstats inteface is enabled and 10 the common fields and basic accounting fields are collected for 11 delivery at do_exit() of a task. 122) Delay accounting fields 13 These fields are placed between 14 /* Delay accounting fields start */ 15 and 16 /* Delay accounting fields end */ 17 Their values are collected if CONFIG_TASK_DELAY_ACCT is set. 183) Extended accounting fields 19 These fields are placed between 20 /* Extended accounting fields start */ 21 and 22 /* Extended accounting fields end */ 23 Their values are collected if CONFIG_TASK_XACCT is set. 24 25Future extension should add fields to the end of the taskstats struct, and 26should not change the relative position of each field within the struct. 27 28 29struct taskstats { 30 311) Common and basic accounting fields: 32 /* The version number of this struct. This field is always set to 33 * TAKSTATS_VERSION, which is defined in <linux/taskstats.h>. 34 * Each time the struct is changed, the value should be incremented. 35 */ 36 __u16 version; 37 38 /* The exit code of a task. */ 39 __u32 ac_exitcode; /* Exit status */ 40 41 /* The accounting flags of a task as defined in <linux/acct.h> 42 * Defined values are AFORK, ASU, ACOMPAT, ACORE, and AXSIG. 43 */ 44 __u8 ac_flag; /* Record flags */ 45 46 /* The value of task_nice() of a task. */ 47 __u8 ac_nice; /* task_nice */ 48 49 /* The name of the command that started this task. */ 50 char ac_comm[TS_COMM_LEN]; /* Command name */ 51 52 /* The scheduling discipline as set in task->policy field. */ 53 __u8 ac_sched; /* Scheduling discipline */ 54 55 __u8 ac_pad[3]; 56 __u32 ac_uid; /* User ID */ 57 __u32 ac_gid; /* Group ID */ 58 __u32 ac_pid; /* Process ID */ 59 __u32 ac_ppid; /* Parent process ID */ 60 61 /* The time when a task begins, in [secs] since 1970. */ 62 __u32 ac_btime; /* Begin time [sec since 1970] */ 63 64 /* The elapsed time of a task, in [usec]. */ 65 __u64 ac_etime; /* Elapsed time [usec] */ 66 67 /* The user CPU time of a task, in [usec]. */ 68 __u64 ac_utime; /* User CPU time [usec] */ 69 70 /* The system CPU time of a task, in [usec]. */ 71 __u64 ac_stime; /* System CPU time [usec] */ 72 73 /* The minor page fault count of a task, as set in task->min_flt. */ 74 __u64 ac_minflt; /* Minor Page Fault Count */ 75 76 /* The major page fault count of a task, as set in task->maj_flt. */ 77 __u64 ac_majflt; /* Major Page Fault Count */ 78 79 802) Delay accounting fields: 81 /* Delay accounting fields start 82 * 83 * All values, until the comment "Delay accounting fields end" are 84 * available only if delay accounting is enabled, even though the last 85 * few fields are not delays 86 * 87 * xxx_count is the number of delay values recorded 88 * xxx_delay_total is the corresponding cumulative delay in nanoseconds 89 * 90 * xxx_delay_total wraps around to zero on overflow 91 * xxx_count incremented regardless of overflow 92 */ 93 94 /* Delay waiting for cpu, while runnable 95 * count, delay_total NOT updated atomically 96 */ 97 __u64 cpu_count; 98 __u64 cpu_delay_total; 99 100 /* Following four fields atomically updated using task->delays->lock */ 101 102 /* Delay waiting for synchronous block I/O to complete 103 * does not account for delays in I/O submission 104 */ 105 __u64 blkio_count; 106 __u64 blkio_delay_total; 107 108 /* Delay waiting for page fault I/O (swap in only) */ 109 __u64 swapin_count; 110 __u64 swapin_delay_total; 111 112 /* cpu "wall-clock" running time 113 * On some architectures, value will adjust for cpu time stolen 114 * from the kernel in involuntary waits due to virtualization. 115 * Value is cumulative, in nanoseconds, without a corresponding count 116 * and wraps around to zero silently on overflow 117 */ 118 __u64 cpu_run_real_total; 119 120 /* cpu "virtual" running time 121 * Uses time intervals seen by the kernel i.e. no adjustment 122 * for kernel's involuntary waits due to virtualization. 123 * Value is cumulative, in nanoseconds, without a corresponding count 124 * and wraps around to zero silently on overflow 125 */ 126 __u64 cpu_run_virtual_total; 127 /* Delay accounting fields end */ 128 /* version 1 ends here */ 129 130 1313) Extended accounting fields 132 /* Extended accounting fields start */ 133 134 /* Accumulated RSS usage in duration of a task, in MBytes-usecs. 135 * The current rss usage is added to this counter every time 136 * a tick is charged to a task's system time. So, at the end we 137 * will have memory usage multiplied by system time. Thus an 138 * average usage per system time unit can be calculated. 139 */ 140 __u64 coremem; /* accumulated RSS usage in MB-usec */ 141 142 /* Accumulated virtual memory usage in duration of a task. 143 * Same as acct_rss_mem1 above except that we keep track of VM usage. 144 */ 145 __u64 virtmem; /* accumulated VM usage in MB-usec */ 146 147 /* High watermark of RSS usage in duration of a task, in KBytes. */ 148 __u64 hiwater_rss; /* High-watermark of RSS usage */ 149 150 /* High watermark of VM usage in duration of a task, in KBytes. */ 151 __u64 hiwater_vm; /* High-water virtual memory usage */ 152 153 /* The following four fields are I/O statistics of a task. */ 154 __u64 read_char; /* bytes read */ 155 __u64 write_char; /* bytes written */ 156 __u64 read_syscalls; /* read syscalls */ 157 __u64 write_syscalls; /* write syscalls */ 158 159 /* Extended accounting fields end */ 160 161} 162