Re: [PATCH 1/2] hrtimer: correct a few numbers in comments and printk outputs

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 25 Nov 2009 21:18:39 +0100 (CET)
Thomas Gleixner <tglx@linutronix.de> wrote:

> On Wed, 25 Nov 2009, Andrew Morton wrote:
> 
> > On Tue, 24 Nov 2009 11:14:03 +0100
> > Uwe Kleine-K__nig  <u.kleine-koenig@pengutronix.de> wrote:
> > 
> > > Hello Andrew,
> > > 
> > > On Mon, Nov 23, 2009 at 03:25:16PM -0800, Andrew Morton wrote:
> > > > On Fri, 20 Nov 2009 20:23:39 +0100
> > > > Uwe Kleine-K__nig  <u.kleine-koenig@pengutronix.de> wrote:
> > > > 
> > > > > @@ -52,7 +52,7 @@ int tick_dev_program_event(struct clock_event_device *dev, ktime_t expires,
> > > > >  			printk(KERN_WARNING
> > > > >  			       "CE: %s increasing min_delta_ns to %lu nsec\n",
> > > > >  			       dev->name ? dev->name : "?",
> > > > > -			       dev->min_delta_ns << 1);
> > > > > +			       dev->min_delta_ns);
> > > > >  
> > > > >  			i = 0;
> > > > >  		}
> > > > 
> > > > This one's already in linux-next:
> > > > 
> > > > @@ -50,9 +50,9 @@ int tick_dev_program_event(struct clock_
> > > >  				dev->min_delta_ns += dev->min_delta_ns >> 1;
> > > >  
> > > >  			printk(KERN_WARNING
> > > > -			       "CE: %s increasing min_delta_ns to %lu nsec\n",
> > > > +			       "CE: %s increasing min_delta_ns to %llu nsec\n",
> > > >  			       dev->name ? dev->name : "?",
> > > > -			       dev->min_delta_ns << 1);
> > > > +			       (unsigned long long) dev->min_delta_ns << 1);
> > > '<< 1' is wrong here, too.
> > > 
> > 
> > What's wrong with it?  That leftshift appears to be to compensate for
> > the rightshift a few lines above.
> > 
> > That change was unobvious and unchangelogged, so here we are again.
> 
> That's actually my fault. In commit 61c22c34 I removed the WARN_ON
> which we put there to gather data on kerneloops.org for a while and
> did not fix the printk format string.
> 

The issue is not the format string.  I'm wondering why Uwe removed that
left-shift of dev->min_delta_ns.