Ingo Molnar wrote:
>
> > Jack wrote:
> > > Should the following change be made to sched_getaffinity().
> > >
> > > Index: linux/kernel/sched.c
> > > ===================================================================
> > > --- linux.orig/kernel/sched.c 2006-01-25 08:50:21.401747695 -0600
> > > +++ linux/kernel/sched.c 2006-01-27 16:57:24.504871895 -0600
> > > @@ -4031,7 +4031,7 @@ long sched_getaffinity(pid_t pid, cpumas
> > > goto out_unlock;
> > >
> > > retval = 0;
> > > - cpus_and(*mask, p->cpus_allowed, cpu_possible_map);
> > > + cpus_and(*mask, p->cpus_allowed, cpu_online_map);
> >
> In any case, Jack's change looks reasonable and obviously correct.
Are you sure? Assuming this change is in effect, consider the
following:
Task starts with default affinity.
Task does sched_getaffinity, stashes the result in saved_mask.
Task pins itself to one cpu and does some work.
Meanwhile, more cpus are brought online.
Task finishes work and does sched_setaffinity(saved_mask).
Task will never run on the new cpus.
-
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/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
