Re: [PATCH 1/4] timer: Added usleep[_range] timer

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

On Wed, 28 Jul 2010 14:05:39 -0700
Patrick Pannuto <ppannuto@codeaurora.org> wrote:

> On 07/28/2010 01:58 PM, Andrew Morton wrote:
> > On Wed, 28 Jul 2010 13:47:46 -0700
> > Patrick Pannuto <ppannuto@codeaurora.org> wrote:
> > 
> >>> This is different from the patch I merged and I'm not seeing any
> >>> explanation for the change.
> >>>
> >>> The implementation of usleep() looks odd.  The longer we sleep, the
> >>> greater the possible inaccuracy.  A code comment which explains the
> >>> thinking and which warns people about the implications is needed.
> > 
> > I wanna code comment!
> > 
> 
> I understand -- will do (if this even survives, which is unlikely)
> 
> > My main concern is that someone will type usleep(50) and won't realise
> > that it goes and sleeps for 100 usecs and their code gets slow as a
> > result.  This sort of thing takes *years* to discover and fix.  If we'd
> > forced them to type usleep_range() instead, it would never have happened.
> 
> In that case, it would push me in the direction of only providing
> usleep_range, and thus forcing people to think about it that way;
> leave slack decisions to people who know what tolerances are acceptable.

Well, I _think_ that would be a good approach.  I'm 45%/55% on that one
and would be interested in other opinions ;)