Jun Sun wrote:
> On Mon, Mar 10, 2003 at 01:55:31PM +0100, Ralf Baechle wrote:
> > On Thu, Mar 06, 2003 at 05:40:01PM -0800, Jun Sun wrote:
> > > I reported this bug last May. Apparently it is still not
> > > taken up-stream. Ralf, why don't we fix it here and push
> > > it up from you?
> > >
> > > BTW, this bug actually has effect on real-time performance under
> > > preemptible kernel.
> > < = 2.4.x preemptible kernel is OPP.
> > > It can delay the execution of the highest
> > > priority real-time process from execution up to 1 jiffy.
> > Quite a number of users get_cycles() in the kernel assume it to return a
> > 64-bit number. I guess we'll have to fake a 64-bit counter in software ...
> Whether we fake 64-bit or not, oldest_idle is declared as cycles_t.
> So comparing it with (cycles_t)-1 should be always be correct. And it
> actually makes a correct C program. :-)
> I don't see any possible reason for rejecting the change. My previous
> report is probably just lost in the noise.
And once again, the patch hasn't made it in. Can we either apply it get
a good reason not to?