Re: [PATCH] timer: Fix jiffies wrap behavior of round_jiffies*()

[Joe Perches]

On Wed, 2013-05-29 at 16:38 -0700, Andrew Morton wrote:
> On Wed, 29 May 2013 16:17:47 -0700 Joe Perches <joe@xxxxxxxxxxx> wrote:
> 
> > >   We could perhaps have a checkpatch rule
> > > which looks for comparisons against jiffes (and any other
> > > time-measuring variables we can detect)
> > 
> > other variables like?
> 
> Grepping for time_after finds a bunch.  There's no real pattern to it though.

Yup, that's the problem.
Thought I'd ask what I was missing though.

No variable really stands out as testable other
than jiffies.

I added this to my local queue and I'll send it later.

# check for comparisons of jiffies
		if ($line =~ /\bif\s*\((\s*jiffies\s*[\<\>]|.*[\<\>]=?\s*jiffies\b)/) {
			WARN("JIFFIES_COMPARISON",
			     "Comparing jiffies is almost always wrong; prefer time_after, time_before and friends\n" . $herecurr);
		}


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/