On Mon, 2005-09-19 at 09:28 +0200, Ingo Molnar wrote:
> * Nick Piggin <[email protected]> wrote:
> > Oh really? I think yes, the latency should be taken care of because we
> > want to be able to provide good latency even for !preempt kernels. If
> > a solution can be found for acpi_processor_idle, that would be ideal.
>
> the ACPI idle code runs with irqs disabled anyway, so there's no issue
> here. If something takes long there, we can do little about it. (but in
> practice ACPI sleep latencies are pretty ok - the only latencies i found
> in the past were due to need_resched bugs in the ACPI idle routine)
>
Ah, in that case I agree: we have nothing to worry about by merging
such a patch then.
> > IMO it always felt kind of hackish to run the idle threads with
> > preempt on.
>
> Yes, idle threads can have preemption disabled. There's not any big
> difference in terms of latencies, the execution paths are all very
> short.
>
Thanks for the confirmation Ingo. This is part of my "cleanup resched
and cpu_idle" patch FYI. It should already be in -mm, but has some
trivial EM64T bug in it that Andrew hits but I can't reproduce.
I'll dust it off and send it out, hopefully someone will be able to
reproduce the problem!
--
SUSE Labs, Novell Inc.
Send instant messages to your online friends http://au.messenger.yahoo.com
-
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]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
| |
 |