Re: [stable] 2.6.23 regression: top displaying 9999% CPU usage

Peter Zijlstra
2007-10-29T21:12:11Z

On Mon, 2007-10-29 at 21:41 +0100, Ingo Molnar wrote:
> * Christian Borntraeger <borntraeger@de.ibm.com> wrote:
>
> > > - return clock_t_to_cputime(utime);
> > > + p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
> > > + return p->prev_utime;
> > > }
> > [...]
> >
> > I dont think it will work. It will make utime monotic, but stime can
> > still decrease. For example let sum_exec_runtime increase by a tiny
> > little bit while utime will get a full additional tick. stime is
> > sum-utime. So stime can still go backwards. So I think that we need
> > this kind of logic for stime as well, no?
>
> yeah, probably. Peter?

/me dons the brown paper bag while mumbling an agreement of sorts.

I'll not attempt to come up with a patch as I fear I'll just make a
bigger mess in my current state, hope to feel better tomorrow..