Hi Chris,
On Fri, Mar 09, 2018 at 10:07:11AM +0000, Chris Redpath wrote:
Hi Leo,
On 09/03/18 08:18, Leo Yan wrote:
On Wed, Mar 07, 2018 at 11:37:30AM +0530, Viresh Kumar wrote:
What about state of the system where the LCD screen is off (not displaying anything) but the platform isn't suspended, like maybe playing audio, software-updates, downloads, etc. Should all threads in such cases land on the big CPUs even if there is no display on LCD (and no UI) ?
Just ask one following question based on Viresh's:
Now Android divide tasks into several cgroup based on UI activities (top-app, foreground, backgroud and system backgroud), I just wander if we can set cgroup schedTune parameters based on different scenarios, but not based on different cgroups?
For example, when Android have hints for 'interactive'/camera/video, we can set schedtune.boost/prefer_idle for top-app & foreground cgroups; otherwise all schedtune.boost/prefer_idle can be cleared. So simply to say, we clear all schedtune flags for most time, and only set them for performance boosting scenarios (touching screen); I even think gaming scenario we don't need these tunable parameters and WALT/PELT signals have enough time to reflect the heavy workload for gaming threads.
What's your suggestion for this?
Absolutely - this falls squarely into the domain of Power HAL. I would only say that the current setup matches well the heuristics present in fbt.
I am a bit confused for this, just as Viresh mentioned the scenario like audio playback with LCD off, usually the SoC has very well optimization for audio island, so even the minor wrongly task placement or OPP increasing can be reflected (the absolute power increasing is not big, but the relative percentage is quite high).
So I think currently we usually set the default boost margin as 10% or 20%, which is not good matching for audio playback with LCD off?
So when we change the assumptions about task classification and schedtune flags, we will have a new optimisation scenario to think about which might work well and might not - I suspect it will largely depend on the device what is suitable or not.
Just want to clarify that rather than proposal new method task classification, I want to know what's better schedtune flag setting with current task classification method.
And for example, if we only set boost margin after Android powerHAL receive 'interactive' hint, does this will introduce how much downgradation for UI performance?
Thanks, Leo Yan