Initial import

1 files changed, 158 insertions, 0 deletions

diff --git a/kernel/delayacct.c b/kernel/delayacct.c
new file mode 100644
index 000000000..d12807d40
--- /dev/null
+++ b/kernel/delayacct.c
@@ -0,0 +1,158 @@
+/* delayacct.c - per-task delay accounting
+ *
+ * Copyright (C) Shailabh Nagar, IBM Corp. 2006
+ *
+ * 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 would 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/sched.h>
+#include <linux/slab.h>
+#include <linux/taskstats.h>
+#include <linux/time.h>
+#include <linux/sysctl.h>
+#include <linux/delayacct.h>
+#include <linux/module.h>
+
+int delayacct_on __read_mostly = 1;	/* Delay accounting turned on/off */
+EXPORT_SYMBOL_GPL(delayacct_on);
+struct kmem_cache *delayacct_cache;
+
+static int __init delayacct_setup_disable(char *str)
+{
+	delayacct_on = 0;
+	return 1;
+}
+__setup("nodelayacct", delayacct_setup_disable);
+
+void delayacct_init(void)
+{
+	delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC);
+	delayacct_tsk_init(&init_task);
+}
+
+void __delayacct_tsk_init(struct task_struct *tsk)
+{
+	tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL);
+	if (tsk->delays)
+		spin_lock_init(&tsk->delays->lock);
+}
+
+/*
+ * Finish delay accounting for a statistic using its timestamps (@start),
+ * accumalator (@total) and @count
+ */
+static void delayacct_end(u64 *start, u64 *total, u32 *count)
+{
+	s64 ns = ktime_get_ns() - *start;
+	unsigned long flags;
+
+	if (ns > 0) {
+		spin_lock_irqsave(&current->delays->lock, flags);
+		*total += ns;
+		(*count)++;
+		spin_unlock_irqrestore(&current->delays->lock, flags);
+	}
+}
+
+void __delayacct_blkio_start(void)
+{
+	current->delays->blkio_start = ktime_get_ns();
+}
+
+void __delayacct_blkio_end(void)
+{
+	if (current->delays->flags & DELAYACCT_PF_SWAPIN)
+		/* Swapin block I/O */
+		delayacct_end(&current->delays->blkio_start,
+			&current->delays->swapin_delay,
+			&current->delays->swapin_count);
+	else	/* Other block I/O */
+		delayacct_end(&current->delays->blkio_start,
+			&current->delays->blkio_delay,
+			&current->delays->blkio_count);
+}
+
+int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
+{
+	cputime_t utime, stime, stimescaled, utimescaled;
+	unsigned long long t2, t3;
+	unsigned long flags, t1;
+	s64 tmp;
+
+	task_cputime(tsk, &utime, &stime);
+	tmp = (s64)d->cpu_run_real_total;
+	tmp += cputime_to_nsecs(utime + stime);
+	d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;
+
+	task_cputime_scaled(tsk, &utimescaled, &stimescaled);
+	tmp = (s64)d->cpu_scaled_run_real_total;
+	tmp += cputime_to_nsecs(utimescaled + stimescaled);
+	d->cpu_scaled_run_real_total =
+		(tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp;
+
+	/*
+	 * No locking available for sched_info (and too expensive to add one)
+	 * Mitigate by taking snapshot of values
+	 */
+	t1 = tsk->sched_info.pcount;
+	t2 = tsk->sched_info.run_delay;
+	t3 = tsk_seruntime(tsk);
+
+	d->cpu_count += t1;
+
+	tmp = (s64)d->cpu_delay_total + t2;
+	d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp;
+
+	tmp = (s64)d->cpu_run_virtual_total + t3;
+	d->cpu_run_virtual_total =
+		(tmp < (s64)d->cpu_run_virtual_total) ?	0 : tmp;
+
+	/* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */
+
+	spin_lock_irqsave(&tsk->delays->lock, flags);
+	tmp = d->blkio_delay_total + tsk->delays->blkio_delay;
+	d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp;
+	tmp = d->swapin_delay_total + tsk->delays->swapin_delay;
+	d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp;
+	tmp = d->freepages_delay_total + tsk->delays->freepages_delay;
+	d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp;
+	d->blkio_count += tsk->delays->blkio_count;
+	d->swapin_count += tsk->delays->swapin_count;
+	d->freepages_count += tsk->delays->freepages_count;
+	spin_unlock_irqrestore(&tsk->delays->lock, flags);
+
+	return 0;
+}
+
+__u64 __delayacct_blkio_ticks(struct task_struct *tsk)
+{
+	__u64 ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tsk->delays->lock, flags);
+	ret = nsec_to_clock_t(tsk->delays->blkio_delay +
+				tsk->delays->swapin_delay);
+	spin_unlock_irqrestore(&tsk->delays->lock, flags);
+	return ret;
+}
+
+void __delayacct_freepages_start(void)
+{
+	current->delays->freepages_start = ktime_get_ns();
+}
+
+void __delayacct_freepages_end(void)
+{
+	delayacct_end(&current->delays->freepages_start,
+			&current->delays->freepages_delay,
+			&current->delays->freepages_count);
+}
+