--- /dev/null
+The struct taskstats
+--------------------
+
+This document contains an explanation of the struct taskstats fields.
+
+There are three different groups of fields in the struct taskstats:
+
+1) Common and basic accounting fields
+ If CONFIG_TASKSTATS is set, the taskstats inteface is enabled and
+ the common fields and basic accounting fields are collected for
+ delivery at do_exit() of a task.
+2) Delay accounting fields
+ These fields are placed between
+ /* Delay accounting fields start */
+ and
+ /* Delay accounting fields end */
+ Their values are collected if CONFIG_TASK_DELAY_ACCT is set.
+3) Extended accounting fields
+ These fields are placed between
+ /* Extended accounting fields start */
+ and
+ /* Extended accounting fields end */
+ Their values are collected if CONFIG_TASK_XACCT is set.
+
+Future extension should add fields to the end of the taskstats struct, and
+should not change the relative position of each field within the struct.
+
+
+struct taskstats {
+
+1) Common and basic accounting fields:
+ /* 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 */
+
+
+2) Delay accounting fields:
+ /* 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 */
+
+
+3) Extended accounting fields
+ /* 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 */
+
+}
#define TASKSTATS_VERSION 2
-#define TS_COMM_LEN 16 /* should sync up with TASK_COMM_LEN
+#define TS_COMM_LEN 32 /* should be >= TASK_COMM_LEN
* in linux/sched.h */
struct taskstats {
- /* Version 1 */
+ /* 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;
- __u32 ac_exitcode; /* Exit status */
+ __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 */
__u8 ac_nice; /* task_nice */
__u64 ac_etime; /* Elapsed time [usec] */
__u64 ac_utime; /* User CPU time [usec] */
__u64 ac_stime; /* SYstem CPU time [usec] */
- __u64 ac_minflt; /* Minor Page Fault */
- __u64 ac_majflt; /* Major Page Fault */
+ __u64 ac_minflt; /* Minor Page Fault Count */
+ __u64 ac_majflt; /* Major Page Fault Count */
/* Basic Accounting Fields end */
/* Extended accounting fields start */
- __u64 acct_rss_mem1; /* accumulated rss usage */
- __u64 acct_vm_mem1; /* accumulated virtual memory usage */
- __u64 hiwater_rss; /* High-watermark of RSS usage */
- __u64 hiwater_vm; /* High-water virtual memory usage */
+ /* 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 and virtual memory usage in duration of
+ * a task, in KBytes.
+ */
+ __u64 hiwater_rss; /* High-watermark of RSS usage, in KB */
+ __u64 hiwater_vm; /* High-water VM usage, in KB */
+
+ /* 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 */
#include <linux/sched.h>
#include <linux/tsacct_kern.h>
#include <linux/acct.h>
+#include <linux/jiffies.h>
#define USEC_PER_TICK (USEC_PER_SEC/HZ)
stats->ac_stime = cputime_to_msecs(tsk->stime) * USEC_PER_MSEC;
stats->ac_minflt = tsk->min_flt;
stats->ac_majflt = tsk->maj_flt;
- /* Each process gets a minimum of one usec cpu time */
- if ((stats->ac_utime == 0) && (stats->ac_stime == 0)) {
- stats->ac_stime = 1;
- }
strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm));
}
#ifdef CONFIG_TASK_XACCT
+
+#define KB 1024
+#define MB (1024*KB)
/*
* fill in extended accounting fields
*/
void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
{
- stats->acct_rss_mem1 = p->acct_rss_mem1;
- stats->acct_vm_mem1 = p->acct_vm_mem1;
+ /* convert pages-jiffies to Mbyte-usec */
+ stats->coremem = jiffies_to_usecs(p->acct_rss_mem1) * PAGE_SIZE / MB;
+ stats->virtmem = jiffies_to_usecs(p->acct_vm_mem1) * PAGE_SIZE / MB;
if (p->mm) {
- stats->hiwater_rss = p->mm->hiwater_rss;
- stats->hiwater_vm = p->mm->hiwater_vm;
+ /* adjust to KB unit */
+ stats->hiwater_rss = p->mm->hiwater_rss * PAGE_SIZE / KB;
+ stats->hiwater_vm = p->mm->hiwater_vm * PAGE_SIZE / KB;
}
stats->read_char = p->rchar;
stats->write_char = p->wchar;
stats->read_syscalls = p->syscr;
stats->write_syscalls = p->syscw;
}
-
+#undef KB
+#undef MB
/**
* acct_update_integrals - update mm integral fields in task_struct
void acct_update_integrals(struct task_struct *tsk)
{
if (likely(tsk->mm)) {
- long delta =
- cputime_to_jiffies(tsk->stime) - tsk->acct_stimexpd;
+ long delta = cputime_to_jiffies(
+ cputime_sub(tsk->stime, tsk->acct_stimexpd));
if (delta == 0)
return;