[PATCH] csa: basic accounting over taskstats

Add some basic accounting fields to the taskstats struct, add a new
kernel/tsacct.c to handle basic accounting data handling upon exit.  A handle
is added to taskstats.c to invoke the basic accounting data handling.

Signed-off-by: Jay Lan <jlan@sgi.com>
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>
Cc: "Michal Piotrowski" <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/Makefile b/kernel/Makefile
index e210e8c..aacaafb 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -49,7 +49,7 @@
 obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
 obj-$(CONFIG_RELAY) += relay.o
 obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
-obj-$(CONFIG_TASKSTATS) += taskstats.o
+obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
 
 ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
 # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index c451af2..6c38dce 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -18,6 +18,7 @@
 
 #include <linux/kernel.h>
 #include <linux/taskstats_kern.h>
+#include <linux/tsacct_kern.h>
 #include <linux/delayacct.h>
 #include <linux/cpumask.h>
 #include <linux/percpu.h>
@@ -198,7 +199,10 @@
 	 */
 
 	delayacct_add_tsk(stats, tsk);
+
+	/* fill in basic acct fields */
 	stats->version = TASKSTATS_VERSION;
+	bacct_add_tsk(stats, tsk);
 
 	/* Define err: label here if needed */
 	put_task_struct(tsk);
diff --git a/kernel/tsacct.c b/kernel/tsacct.c
new file mode 100644
index 0000000..8990679
--- /dev/null
+++ b/kernel/tsacct.c
@@ -0,0 +1,72 @@
+/*
+ * tsacct.c - System accounting over taskstats interface
+ *
+ * Copyright (C) Jay Lan,	<jlan@sgi.com>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/tsacct_kern.h>
+#include <linux/acct.h>
+
+
+#define USEC_PER_TICK	(USEC_PER_SEC/HZ)
+/*
+ * fill in basic accounting fields
+ */
+void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk)
+{
+	struct timespec uptime, ts;
+	s64 ac_etime;
+
+	BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
+
+	/* calculate task elapsed time in timespec */
+	do_posix_clock_monotonic_gettime(&uptime);
+	ts = timespec_sub(uptime, current->group_leader->start_time);
+	/* rebase elapsed time to usec */
+	ac_etime = timespec_to_ns(&ts);
+	do_div(ac_etime, NSEC_PER_USEC);
+	stats->ac_etime = ac_etime;
+	stats->ac_btime = xtime.tv_sec - ts.tv_sec;
+	if (thread_group_leader(tsk)) {
+		stats->ac_exitcode = tsk->exit_code;
+		if (tsk->flags & PF_FORKNOEXEC)
+			stats->ac_flag |= AFORK;
+	}
+	if (tsk->flags & PF_SUPERPRIV)
+		stats->ac_flag |= ASU;
+	if (tsk->flags & PF_DUMPCORE)
+		stats->ac_flag |= ACORE;
+	if (tsk->flags & PF_SIGNALED)
+		stats->ac_flag |= AXSIG;
+	stats->ac_nice	 = task_nice(tsk);
+	stats->ac_sched	 = tsk->policy;
+	stats->ac_uid	 = tsk->uid;
+	stats->ac_gid	 = tsk->gid;
+	stats->ac_pid	 = tsk->pid;
+	stats->ac_ppid	 = (tsk->parent) ? tsk->parent->pid : 0;
+	stats->ac_utime	 = cputime_to_msecs(tsk->utime) * USEC_PER_MSEC;
+	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));
+}
+