Paul Jackson wrote:
> Nathan wrote:
> > Which is problematic, because cpuset_cpus_allowed ->
> > guarantee_online_cpus restricts the task->cpus_allowed mask to cpus
> > which happen to be online at the time of the call to
> > sched_setaffinity. If more cpus come online later, that task can't be
> > migrated to them.
>
> Well, sort of.
>
> A task could always migrate - just because a sched_getaffinity
> the task did in the past doesn't show a CPU as valid, doesn't stop
> the task from asking to pin to that CPU now.
I was speaking of the setaffinity (not getaffinity) case -- I assumed
this was what you were referring to since I couldn't find any calls to
the cpuset code in the getaffinity path.
> One of three lessons could be taken from your example:
> 1) return all possible CPUS (CPU_MASK_ALL, likely), as you
> recommend
I'm only recommending not changing the current behavior of
sched_getaffinity.
(BTW - cpu_possible_map can be a subset of CPU_MASK_ALL on some
platforms -- powerpc, at least, since we can discover the number of
truly possible cpus early in boot.)
-
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]
