On 20/09/16 13:02, Saravana Kannan wrote:
On 09/20/2016 02:09 AM, Juri Lelli wrote:
Hi,
On 19/09/16 14:54, Saravana Kannan wrote:
On 09/16/2016 09:15 AM, Juri Lelli wrote:
Hi,
In preparation for a Connect LAS16 hacking sessions, I've been trying to compare schedfreq with schedutil with EAS on Hikey running Android 4.4. In the document below you can view some preliminary results of what I found. Please excuse the brevity; I'm sure way more comments would be needed to make the document more understandable, but I hope it's still useful and I wanted to share it as soon as possible. Please don't hesitate to ask for more information or clarifications (best is by commenting directly on the document, I think).
https://docs.google.com/document/d/1tMb9yfJgaZmVANbbhTWwjLQLA2v5tj-_aTLXDeSu...
tl;dr;
- merging pain wasn't so bad
- schedutil relatively close to schedfreq and interactive (even if high percentiles seems to be quite off): perf is lower, but saving some energy
When you say "interactive" what version of the interactive governor are you using?
The one that's in the Android 4.4 Hikey build.
Hmmm... AFAIK, that one isn't going to get any benefit from WALT. The one that ships with MSM chips is quite a bit different and works closely with WALT. Not saying we'll have to port it over and collect numbers, but this doesn't give a good picture of the interactive governor that ships on a lot of phones.
Put another way, if there are some good parts to interactive (like the tunables it provides) that we'd eventually want to encourage adding to sched-util, it won't be made apparent from this test.
Right. And I guess that is similarly true for schedfreq (as it is not coupled with schedtune and userspace hints in these tests).
However, I still believe these numbers are somewhat helpful in understanding how far are the "bare" governors from each other in terms of performance and power. We shouldn't use them to drive any conclusive decisions of course but, IMHO they are a good start at comparing things more fairly.
Best,
- Juri