On 03/16, Eric Dumazet wrote:
>
> On Friday 16 March 2007 18:10, Oleg Nesterov wrote:
> > Eric Dumazet wrote:
> > > @@ -2021,6 +2022,8 @@ static void k_getrusage(struct task_stru
> > > r->ru_nivcsw = p->signal->cnivcsw;
> > > r->ru_minflt = p->signal->cmin_flt;
> > > r->ru_majflt = p->signal->cmaj_flt;
> > > + r->ru_inblock = task_io_get_inblock(p);
> > > + r->ru_oublock = task_io_get_oublock(p);
> > >
> > > if (who == RUSAGE_CHILDREN)
> > > break;
> > > @@ -2032,6 +2035,8 @@ static void k_getrusage(struct task_stru
> > > r->ru_nivcsw += p->signal->nivcsw;
> > > r->ru_minflt += p->signal->min_flt;
> > > r->ru_majflt += p->signal->maj_flt;
> > > + r->ru_inblock += task_io_get_inblock(p);
> > > + r->ru_oublock += task_io_get_oublock(p);
> > > t = p;
> > > do {
> > > utime = cputime_add(utime, t->utime);
> > > @@ -2040,6 +2045,8 @@ static void k_getrusage(struct task_stru
> > > r->ru_nivcsw += t->nivcsw;
> > > r->ru_minflt += t->min_flt;
> > > r->ru_majflt += t->maj_flt;
> > > + r->ru_inblock += task_io_get_inblock(t);
> > > + r->ru_oublock += task_io_get_oublock(t);
> >
> > I can't understand this. Consider k_getrusage(RUSAGE_BOTH). The end result
> > is that r->ru_inblock == 3 * task_io_get_inblock(p).
> >
> > No?
>
> Yes :)
>
> Very good point, you found a bug in k_getrusage().
No, no, please check the code.
> So not only ru_inblock/ru_oublock are multiplied by 3 : others fields as well
> are wrong.
>
> Also the definition of RUSAGE_CHILDREN is not conformant to standard
>
> http://www.opengroup.org/onlinepubs/009695399/functions/getrusage.html
>
> "If the value of the who argument is RUSAGE_CHILDREN, information shall
> be
> "returned about resources used by the terminated and waited-for
> children of
> "the current process
This exactly happens. We are reading ->signal->*, see wait_task_zombie().
> We currently do a sum of rusage stats of still alive children.. thats totally
> wrong...
I hope not :)
Oleg.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
