Messages in this thread | | | Date | Mon, 9 Nov 2015 15:15:34 +0100 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH 0/3] CFS idle injection |
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On Mon, Nov 09, 2015 at 11:56:51AM +0000, Punit Agrawal wrote: > Jacob Pan <jacob.jun.pan@linux.intel.com> writes: > > My take is that RT and throttling will never go well together since they > > are conflicting in principle. > > I am not sure I follow. If RT (or other higher priority classes) can't > be throttled then the CPUs are not able to contribute towards > constraining power consumption and hence temperature. > > This is especially true in certain platforms where tasks belong to the > RT class to maintain user experience, e.g., audio and video.
Audio/Video playback generally doesn't take a _lot_ of time these days. What is important though is _when_ it happens.
And media playback typically already has a very well defined and stable cadence (24Hz or whatnot). What you want is for your idle injector to sync up with that, not disrupt it.
For other workloads, missing a deadline is about as bad as destroying the chip, complete system shutdown might be safer than getting delayed. (The very tired scenario of a saw, a laser and your finger; you want to shut down the entire machine rather than just cut off your finger.)
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