Messages in this thread | | | Date | Mon, 22 May 2017 21:34:52 +0800 | From | Leo Yan <> | Subject | Re: [PATCH] ARM: cpuidle: Support asymmetric idle definition |
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Hi Sudeep,
On Mon, May 22, 2017 at 02:02:12PM +0100, Sudeep Holla wrote:
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> >>>> On 19/05/17 17:45, Daniel Lezcano wrote: > >>>>> Some hardware have clusters with different idle states. The current code does > >>>>> not support this and fails as it expects all the idle states to be identical. > >>>>> > >>>>> Because of this, the Mediatek mtk8173 had to create the same idle state for a > >>>>> big.Little system and now the Hisilicon 960 is facing the same situation. > >>>>> > >>>> > >>>> While I agree the we don't support them today, it's better to benchmark > >>>> and record/compare the gain we get with the support for cluster based > >>>> idle states. > >>> > >>> Sorry, I don't get what you are talking about. What do you want to > >>> benchmark ? Cluster idling ? > >>> > >> > >> OK, I was not so clear. I had a brief chat with Lorenzo, we have few > >> reason to have this support: > >> 1. Different number of states between clusters > >> 2. Different latencies(this is the one I was referring above, generally > >> we keep worst case timings here and wanted to see if any platform > >> measured improvements with different latencies in the idle states) > > > > I don't see the point. Are you putting into question the big little design? > > > > Not exactly. Since they are generally worst case number, I wanted to > check if someone saw real benefit with 2 different set of values. > Anyways that's not important or blocking, just raised a point, so that > we can stick some benchmarking results with this.
In case you are interesting for Hikey960 idle states, you could see the two clustsers have different idle states: http://termbin.com/d7ed
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Thanks, Leo Yan
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