* Siddha, Suresh B <[email protected]> wrote:
> In the presence of SMT, newly idle balance was never happening for
> multi-core and SMP domains(even when both the logical siblings are
> idle).
>
> If thread 0 is already idle and when thread 1 is about to go to idle,
> newly idle load balance always think that one of the threads is not
> idle and skips doing the newly idle load balance for multi-core and
> SMP domains.
>
> This is because of the idle_cpu() macro, which checks if the current
> process on a cpu is an idle process. But this is not the case for the
> thread doing the load_balance_newidle().
>
> Fix this by using runqueue's nr_running field instead of idle_cpu().
> And also skip the logic of 'only one idle cpu in the group will be
> doing load balancing' during newly idle case.
ah, indeed - good catch! I've checked the other uses of idle_cpu() and
those seem to be fine. I've added your patch to my queue.
Ingo
-
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]
