Re: Hyper-Threading Vulnerability

Arjan van de Ven
2005-05-16T08:28:59Z

On Sun, 2005-05-15 at 19:10 -0400, Lee Revell wrote:
> On Sun, 2005-05-15 at 18:55 -0400, Dave Jones wrote:
> > On Sun, May 15, 2005 at 05:10:59PM -0400, Lee Revell wrote:
> > > On Sun, 2005-05-15 at 22:48 +0200, Arjan van de Ven wrote:
> > > > On Sun, 2005-05-15 at 21:41 +0100, Alan Cox wrote:
> > > > > On Sul, 2005-05-15 at 08:30, Arjan van de Ven wrote:
> > > > > > stop entirely.... (and that is also happening more and more and linux is
> > > > > > getting more agressive idle support (eg no timer tick and such patches)
> > > > > > which will trigger bios thresholds for this even more too.
> > > > >
> > > > > Cyrix did TSC stop on halt a long long time ago, back when it was worth
> > > > > the power difference.
> > > >
> > > > With linux going to ACPI C2 mode more... tsc is defined to halt in C2...
> > >
> > > JACK doesn't care about any of this now, the behavior when you
> > > suspend/resume with a running jackd is undefined. Eventually we should
> > > handle it, but there's no point until the ALSA drivers get proper
> > > suspend/resume support.
> >
> > suspend/resume are S states, not C states. C states are occuring
> > during runtime.
>
> It should never go into C2 if jackd is running, because you're getting
> interrupts from the audio interface at least every 100ms or so (usually
> much more often) which will wake up jackd and any clients.

you're not guaranteed to not enter C2 in that case. C2 can happen after
a few ms already