On Thu, Nov 05, 2015 at 06:22:58AM -0800, Arjan van de Ven wrote: > On 11/5/2015 2:09 AM, Peter Zijlstra wrote: > > >I can see such a scheme having a fairly big impact on latency, esp. with > >forced idleness such as this. That's not going to be popular for many > >workloads. > > idle injection is a last ditch effort in thermal management, before > this gets used the hardware already has clamped you to a low frequency, > reduced memory speeds, probably dimmed your screen etc etc. > > at this point there are 3 choices > 1) Shut off the device > 2) do uncoordinated idle injection for 40% of the time > 3) do coordinated idle injection for 5% of the time > > as much as force injecting idle in a synchronized way sucks, the alternatives > are worse.
OK, it wasn't put that way. I figured it was a way to use less power on any workload with idle time on. That said; what kind of devices are we talking about here; mobile with pittyful heat dissipation? Surely a well designed server or desktop class system should never get into this situation in the first place. -- 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/
