Re: patch to fix set_itimer() behaviour in boundary cases

[Arjan van de Ven <arjan@infradead.org>]

On Wed, 2005-01-19 at 15:51 -0800, George Anzinger wrote:
> Arjan van de Ven wrote:
> > On Sun, 2005-01-16 at 00:58 +0000, Alan Cox wrote:
> > 
> >>On Sad, 2005-01-15 at 09:30, Andrew Morton wrote:
> >>
> >>>Matthias Lang <matthias@corelatus.se> wrote:
> >>>These are things we probably cannot change now.  All three are arguably
> >>>sensible behaviour and do satisfy the principle of least surprise.  So
> >>>there may be apps out there which will break if we "fix" these things.
> >>>
> >>>If the kernel version was 2.7.0 then well maybe...
> >>
> >>These are things we should fix. They are bugs. Since there is no 2.7
> >>plan pick a date to fix it. We should certainly error the overflow case
> >>*now* because the behaviour is undefined/broken. The other cases I'm not
> >>clear about. setitimer() is a library interface and it can do the basic
> >>checking and error if it wants to be strictly posixly compliant.
> > 
> > 
> > why error?
> > I'm pretty sure we can make a loop in the setitimer code that detects
> > we're at the end of jiffies but haven't upsurped the entire interval the
> > user requested yet, so that the code should just do another round of
> > sleeping...
> > 
> That would work for sleep (but glibc uses nanosleep for that) but an itimer 
> delivers a signal.  Rather hard to trap that in glibc.
> 
This one I meant to fix in the kernel fwiw; we can put that loop inside
the kernel easily I'm sure