Re: [PATCH] Real-Time Preemption, using msecs_to_jiffies() instead of HZ

From: Ingo Molnar
Date: Sat Jun 11 2005 - 08:37:28 EST



* Luca Falavigna <dktrkranz@xxxxxxxxx> wrote:

> 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)) {
> ...
> }

oops, indeed. (i've also forwarded your patch to akpm, as the softlockup
patch is included in -mm too)

> 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:

> ++ msleep(msecs_to_jiffies(20));
> ++ msleep(msecs_to_jiffies(100));
> ++ msleep_interruptible(msecs_to_jiffies(1000));

actually, this should be msleep(20/100/1000). I've fixed these in my
tree.

Ingo
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