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Date: Mon, 10 Mar 2003 14:29:44 -0800
From: Andrew Morton <akpm@digeo.com>
To: george anzinger <george@mvista.com>
Cc: torvalds@transmeta.com, cobra@compuserve.com, linux-kernel@vger.kernel.org
Subject: Re: Runaway cron task on 2.5.63/4 bk?
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george anzinger <george@mvista.com> wrote:
>
> Linus Torvalds wrote:
> > On Mon, 10 Mar 2003, george anzinger wrote:
> > 
> >>Lets consider this one on its own merits.  What SHOULD sleep do when 
> >>asked to sleep for MAX_INT number of jiffies or more, i.e. when 
> >>jiffies overflows?  My notion, above, it that it is clearly an error. 
> > 
> > 
> > My suggestion (in order of preference):
> >  - sleep the max amount, and then restart as if a signal had happened
> 
> I think this will require a 64-bit expire in the timer_struct 
> (actually it would not be treated as such, but the struct would still 
> need the added bits).  Is this ok?
> 
> I will look at the problem in detail and see if there might be another 
> way without the need of the added bits.

Is it not possible to just sit in a loop, sleeping for 0x7fffffff jiffies
on each iteration?  (Until the final partial bit of course)

> Hm...  I changed it to what it is to make it easier to track down 
> problems in the test code... and this was user code.  My thinking was 
> that such large values are clear errors, and having the code "hang" in 
> the sleep just hides the problem.  But then, I NEVER make a system 
> call without checking for errors....  And, I was making a LOT of sleep 
> calls and wanted to know which one(s) were wrong.

If an app wants to sleep forever, calling

	while (1)
		sleep(MAX_INT);

seems like a reasonable approach.  I'd expect quite a lot of applications
would be doing that.

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