On Thu, 21 Jun 2012 16:10:23 -0700 "H. Peter Anvin" <hpa@xxxxxxxxx> wrote: > On 06/21/2012 03:51 PM, Andrew Morton wrote: > > > > What *is* significant is the effect of a signedness change upon > > arithmetic, conversions, warnings, etc. And whether such a change > > might actually introduce bugs. > > > > > > Back away and ask the broader questions: why did ktime_t choose > > unsigned? Is time a signed concept? What is the right thing to do > > here, from a long-term design perspective? > > Time is definitely a signed concept -- it has no beginning or end (well, > the Big Bang, but the __110 Myr or so uncertainty of the exact timing of > the Big Bang makes it a horridly awkward choice for epoch.) > > Now, for some users of time you can inherently guarantee there will > never be any references to time before a particular event, e.g. system > boot, in which case an unsigned number might make sense, but as a whole > I think using a signed type as time_t in nearly all Unix implementation > was The Right Thing. > So why is ktime_t unsigned? -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html