Based on kernel version 4.16.1. Page generated on 2018-04-09 11:52 EST.
1 The struct taskstats 2 -------------------- 3 4 This document contains an explanation of the struct taskstats fields. 5 6 There are three different groups of fields in the struct taskstats: 7 8 1) Common and basic accounting fields 9 If CONFIG_TASKSTATS is set, the taskstats interface is enabled and 10 the common fields and basic accounting fields are collected for 11 delivery at do_exit() of a task. 12 2) 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. 18 3) 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 25 4) Per-task and per-thread context switch count statistics 26 27 5) Time accounting for SMT machines 28 29 6) Extended delay accounting fields for memory reclaim 30 31 Future extension should add fields to the end of the taskstats struct, and 32 should not change the relative position of each field within the struct. 33 34 35 struct taskstats { 36 37 1) Common and basic accounting fields: 38 /* The version number of this struct. This field is always set to 39 * TAKSTATS_VERSION, which is defined in <linux/taskstats.h>. 40 * Each time the struct is changed, the value should be incremented. 41 */ 42 __u16 version; 43 44 /* The exit code of a task. */ 45 __u32 ac_exitcode; /* Exit status */ 46 47 /* The accounting flags of a task as defined in <linux/acct.h> 48 * Defined values are AFORK, ASU, ACOMPAT, ACORE, and AXSIG. 49 */ 50 __u8 ac_flag; /* Record flags */ 51 52 /* The value of task_nice() of a task. */ 53 __u8 ac_nice; /* task_nice */ 54 55 /* The name of the command that started this task. */ 56 char ac_comm[TS_COMM_LEN]; /* Command name */ 57 58 /* The scheduling discipline as set in task->policy field. */ 59 __u8 ac_sched; /* Scheduling discipline */ 60 61 __u8 ac_pad[3]; 62 __u32 ac_uid; /* User ID */ 63 __u32 ac_gid; /* Group ID */ 64 __u32 ac_pid; /* Process ID */ 65 __u32 ac_ppid; /* Parent process ID */ 66 67 /* The time when a task begins, in [secs] since 1970. */ 68 __u32 ac_btime; /* Begin time [sec since 1970] */ 69 70 /* The elapsed time of a task, in [usec]. */ 71 __u64 ac_etime; /* Elapsed time [usec] */ 72 73 /* The user CPU time of a task, in [usec]. */ 74 __u64 ac_utime; /* User CPU time [usec] */ 75 76 /* The system CPU time of a task, in [usec]. */ 77 __u64 ac_stime; /* System CPU time [usec] */ 78 79 /* The minor page fault count of a task, as set in task->min_flt. */ 80 __u64 ac_minflt; /* Minor Page Fault Count */ 81 82 /* The major page fault count of a task, as set in task->maj_flt. */ 83 __u64 ac_majflt; /* Major Page Fault Count */ 84 85 86 2) Delay accounting fields: 87 /* Delay accounting fields start 88 * 89 * All values, until the comment "Delay accounting fields end" are 90 * available only if delay accounting is enabled, even though the last 91 * few fields are not delays 92 * 93 * xxx_count is the number of delay values recorded 94 * xxx_delay_total is the corresponding cumulative delay in nanoseconds 95 * 96 * xxx_delay_total wraps around to zero on overflow 97 * xxx_count incremented regardless of overflow 98 */ 99 100 /* Delay waiting for cpu, while runnable 101 * count, delay_total NOT updated atomically 102 */ 103 __u64 cpu_count; 104 __u64 cpu_delay_total; 105 106 /* Following four fields atomically updated using task->delays->lock */ 107 108 /* Delay waiting for synchronous block I/O to complete 109 * does not account for delays in I/O submission 110 */ 111 __u64 blkio_count; 112 __u64 blkio_delay_total; 113 114 /* Delay waiting for page fault I/O (swap in only) */ 115 __u64 swapin_count; 116 __u64 swapin_delay_total; 117 118 /* cpu "wall-clock" running time 119 * On some architectures, value will adjust for cpu time stolen 120 * from the kernel in involuntary waits due to virtualization. 121 * Value is cumulative, in nanoseconds, without a corresponding count 122 * and wraps around to zero silently on overflow 123 */ 124 __u64 cpu_run_real_total; 125 126 /* cpu "virtual" running time 127 * Uses time intervals seen by the kernel i.e. no adjustment 128 * for kernel's involuntary waits due to virtualization. 129 * Value is cumulative, in nanoseconds, without a corresponding count 130 * and wraps around to zero silently on overflow 131 */ 132 __u64 cpu_run_virtual_total; 133 /* Delay accounting fields end */ 134 /* version 1 ends here */ 135 136 137 3) Extended accounting fields 138 /* Extended accounting fields start */ 139 140 /* Accumulated RSS usage in duration of a task, in MBytes-usecs. 141 * The current rss usage is added to this counter every time 142 * a tick is charged to a task's system time. So, at the end we 143 * will have memory usage multiplied by system time. Thus an 144 * average usage per system time unit can be calculated. 145 */ 146 __u64 coremem; /* accumulated RSS usage in MB-usec */ 147 148 /* Accumulated virtual memory usage in duration of a task. 149 * Same as acct_rss_mem1 above except that we keep track of VM usage. 150 */ 151 __u64 virtmem; /* accumulated VM usage in MB-usec */ 152 153 /* High watermark of RSS usage in duration of a task, in KBytes. */ 154 __u64 hiwater_rss; /* High-watermark of RSS usage */ 155 156 /* High watermark of VM usage in duration of a task, in KBytes. */ 157 __u64 hiwater_vm; /* High-water virtual memory usage */ 158 159 /* The following four fields are I/O statistics of a task. */ 160 __u64 read_char; /* bytes read */ 161 __u64 write_char; /* bytes written */ 162 __u64 read_syscalls; /* read syscalls */ 163 __u64 write_syscalls; /* write syscalls */ 164 165 /* Extended accounting fields end */ 166 167 4) Per-task and per-thread statistics 168 __u64 nvcsw; /* Context voluntary switch counter */ 169 __u64 nivcsw; /* Context involuntary switch counter */ 170 171 5) Time accounting for SMT machines 172 __u64 ac_utimescaled; /* utime scaled on frequency etc */ 173 __u64 ac_stimescaled; /* stime scaled on frequency etc */ 174 __u64 cpu_scaled_run_real_total; /* scaled cpu_run_real_total */ 175 176 6) Extended delay accounting fields for memory reclaim 177 /* Delay waiting for memory reclaim */ 178 __u64 freepages_count; 179 __u64 freepages_delay_total; 180 }