Re: [PATCH] i386 No-Idle-Hz aka Dynamic-Ticks 3

From: Con Kolivas
Date: Wed Aug 03 2005 - 16:20:55 EST


On Thu, 4 Aug 2005 05:20, Jim MacBaine wrote:
> On 8/3/05, Con Kolivas <kernel@xxxxxxxxxxx> wrote:
> > This is the dynamic ticks patch for i386 as written by Tony Lindgen
> > <tony@xxxxxxxxxxx> and Tuukka Tikkanen <tuukka.tikkanen@xxxxxxxxxxxxxx>.
> > Patch for 2.6.13-rc5
> >
> > There were a couple of things that I wanted to change so here is an
> > updated version. This code should have stabilised enough for general
> > testing now.
>
> Runs very well here on a (noname) laptop, even with apic timer, the
> desktop does not "feel" different from static 1000HZ.

I did find performance dropped off substantially in interbench but usually
below the human perceptible range. Real time performance dropped off
substantially, but is back to mainline performance when disabled (ie config
on but disabled at runtime/boottime).

> But dtck
> reproducibly breaks software-suspend2; the kernel will simply stall on
> resume. Also stalls with dyntick=noapic. As soon as I set
> CONFIG_NO_IDLE_HZ = n, resume works again.

What happens when you disable it at runtime before suspending?

echo 0 > /sys/devices/system/dyn_tick/dyn_tick0/enable

Cheers,
Con

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