[PATCH 1/6] delayacct: Use sched_clock()

From: Peter Zijlstra
Date: Wed May 05 2021 - 07:21:25 EST


Like all scheduler statistics, use sched_clock() based time.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
kernel/delayacct.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)

--- a/kernel/delayacct.c
+++ b/kernel/delayacct.c
@@ -7,9 +7,9 @@
#include <linux/sched.h>
#include <linux/sched/task.h>
#include <linux/sched/cputime.h>
+#include <linux/sched/clock.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>
@@ -42,10 +42,9 @@ void __delayacct_tsk_init(struct task_st
* Finish delay accounting for a statistic using its timestamps (@start),
* accumalator (@total) and @count
*/
-static void delayacct_end(raw_spinlock_t *lock, u64 *start, u64 *total,
- u32 *count)
+static void delayacct_end(raw_spinlock_t *lock, u64 *start, u64 *total, u32 *count)
{
- s64 ns = ktime_get_ns() - *start;
+ s64 ns = local_clock() - *start;
unsigned long flags;

if (ns > 0) {
@@ -58,7 +57,7 @@ static void delayacct_end(raw_spinlock_t

void __delayacct_blkio_start(void)
{
- current->delays->blkio_start = ktime_get_ns();
+ current->delays->blkio_start = local_clock();
}

/*
@@ -151,21 +150,20 @@ __u64 __delayacct_blkio_ticks(struct tas

void __delayacct_freepages_start(void)
{
- current->delays->freepages_start = ktime_get_ns();
+ current->delays->freepages_start = local_clock();
}

void __delayacct_freepages_end(void)
{
- delayacct_end(
- &current->delays->lock,
- &current->delays->freepages_start,
- &current->delays->freepages_delay,
- &current->delays->freepages_count);
+ delayacct_end(&current->delays->lock,
+ &current->delays->freepages_start,
+ &current->delays->freepages_delay,
+ &current->delays->freepages_count);
}

void __delayacct_thrashing_start(void)
{
- current->delays->thrashing_start = ktime_get_ns();
+ current->delays->thrashing_start = local_clock();
}

void __delayacct_thrashing_end(void)