Re: [Patch] Re: Nasty suprise with uptime

[Tim Schmielau]

On Wed, 31 Oct 2001, Andreas Dilger wrote:

> I would say that (excluding stability issues because of jiffies wrap)
> that this is ready for submission to Linus.  He may be of the mind that
> he would rather fix the wrap issues sooner rather than later, or he
> may want to minimize disruption during the "VM stabilize" period (there
> are still a couple of hang issues apparently).
>

I'd rather object for now. I've had a couple of hard freezes within
minutes to hours after jiffies wraparound. Also some KDE applications
behave strange, the KDE panel and kterm need approx 2 min to appear
even before the wraparound (so it seems to be a sign issue rather than
wraparound). I don't want to see this in a stable kernel.

However, I would be pleased if widespread intentional use of the patch
would help to solve the remaining wraparound issues.

> > +u64 get_jiffies64(void)
> > +{
> > +	static unsigned long jiffies_hi = 0;
> > +	static unsigned long jiffies_last = INITIAL_JIFFIES;
> > +	static unsigned long jiffies_tmp;
>         ^^^^^^ jiffies_tmp doesn't need to be static.

Yes, cut and paste error, sorry. And I wanted this patch to be final for
today...

>
> One suggestion someone had was to put dummy "get_jiffies64()" calls
> in some other infrequently used areas to ensure jiffies_hi is valid
> if we don't call uptime for 1.3 years after the first wrap.  I don't
> know if that matters or not.
>

I don't have enough knowledge of the kernel to find good places.
Any suggestions?

Tim