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Subject[PATCH V7 1/4] softirq: Use sched_clock() based timeout
Date
From: jun qian <qianjun.kernel@gmail.com>

Replace the jiffies based timeout with a sched_clock() based one.

Signed-off-by: jun qian <qianjun.kernel@gmail.com>
---
kernel/softirq.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/softirq.c b/kernel/softirq.c
index c4201b7f..0db77ab 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -25,6 +25,7 @@
#include <linux/smpboot.h>
#include <linux/tick.h>
#include <linux/irq.h>
+#include <linux/sched/clock.h>

#define CREATE_TRACE_POINTS
#include <trace/events/irq.h>
@@ -210,7 +211,7 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt)
* we want to handle softirqs as soon as possible, but they
* should not be able to lock up the box.
*/
-#define MAX_SOFTIRQ_TIME msecs_to_jiffies(2)
+#define MAX_SOFTIRQ_TIME (2 * NSEC_PER_MSEC)
#define MAX_SOFTIRQ_RESTART 10

#ifdef CONFIG_TRACE_IRQFLAGS
@@ -248,7 +249,7 @@ static inline void lockdep_softirq_end(bool in_hardirq) { }

asmlinkage __visible void __softirq_entry __do_softirq(void)
{
- unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
+ u64 start = sched_clock();
unsigned long old_flags = current->flags;
int max_restart = MAX_SOFTIRQ_RESTART;
struct softirq_action *h;
@@ -307,7 +308,7 @@ asmlinkage __visible void __softirq_entry __do_softirq(void)

pending = local_softirq_pending();
if (pending) {
- if (time_before(jiffies, end) && !need_resched() &&
+ if (sched_clock() - start < MAX_SOFTIRQ_TIME && !need_resched() &&
--max_restart)
goto restart;

--
1.8.3.1
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