[PATCH] csa accounting taskstats update
ChangeLog:
Feedbacks from Andrew Morton:
- define TS_COMM_LEN to 32
- change acct_stimexpd field of task_struct to be of
cputime_t, which is to be used to save the tsk->stime
of last timer interrupt update.
- a new Documentation/accounting/taskstats-struct.txt
to describe fields of taskstats struct.
Feedback from Balbir Singh:
- keep the stime of a task to be zero when both stime
and utime are zero as recoreded in task_struct.
Misc:
- convert accumulated RSS/VM from platform dependent
pages-ticks to MBytes-usecs in the kernel
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/Documentation/accounting/taskstats-struct.txt b/Documentation/accounting/taskstats-struct.txt
new file mode 100644
index 0000000..661c797
--- /dev/null
+++ b/Documentation/accounting/taskstats-struct.txt
@@ -0,0 +1,161 @@
+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 */
+
+}