From: Luca Falavigna <dktrkranz@gmail.com>
To: mingo@elte.hu
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [PATCH] Real-Time Preemption, using msecs_to_jiffies() instead of HZ
Date: Fri, 10 Jun 2005 16:42:08 +0000 [thread overview]
Message-ID: <42A9C2E0.30002@gmail.com> (raw)
Hi,
I was looking at kernel/softlookup.c when I noticed you used HZ in order to get
a 10-second delay:
void softlockup_tick(struct pt_regs *regs)
{
...
if (time_after(jiffies, timestamp + 10*HZ)) {
...
}
I created this small patch (built against version 2.6.12-rc6-V0.7.48-05) which
does use of msecs_to_jiffies() to get a correct behaviour with every platform.
Similarly I modified function watchdog and kernel/irq/autoprobe.c file
(probe_irq_on function).
Here is the patch:
--- ./rtp-2.6.12-rc6-V0.7.48-05.orig 2005-06-10 16:27:48.000000000 +0000
+++ ./rtp-2.6.12-rc6-V0.7.48-05 2005-06-10 16:30:18.000000000 +0000
@@ -7425,7 +7425,7 @@
+ /*
+ * Wait for longstanding interrupts to trigger, 20 msec delay:
+ */
-+ msleep(HZ/50);
++ msleep(msecs_to_jiffies(20));
/*
* enable any unassigned irqs
@@ -7452,7 +7452,7 @@
*/
- for (delay = jiffies + HZ/10; time_after(delay, jiffies); )
- /* about 100ms delay */ barrier();
-+ msleep(HZ/10);
++ msleep(msecs_to_jiffies(100));
/*
* Now filter out any obviously spurious interrupts
@@ -10712,7 +10712,7 @@
+ if (did_panic)
+ return;
+
-+ if (time_after(jiffies, timestamp + 10*HZ)) {
++ if (time_after(jiffies, timestamp + msecs_to_jiffies(10000))) {
+ per_cpu(print_timestamp, this_cpu) = timestamp;
+
+ spin_lock(&print_lock);
@@ -10748,7 +10748,7 @@
+ */
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
-+ msleep_interruptible(HZ);
++ msleep_interruptible(msecs_to_jiffies(1000));
+ touch_softlockup_watchdog();
+ }
+ __set_current_state(TASK_RUNNING);
Regards,
--
Luca
next reply other threads:[~2005-06-11 11:46 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-06-10 16:42 Luca Falavigna [this message]
2005-06-11 13:32 ` [PATCH] Real-Time Preemption, using msecs_to_jiffies() instead of HZ Ingo Molnar
2005-06-13 2:10 ` Luca Falavigna
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