"X-Lomiri-Touch=true" can cause lags

Eric H

Hello,

Since I updated my phone to focal, there are some lags when switching apps.
These lags have been reported, at least, by all users of this phone (surya).

Yesterday, I tried to comment lines starting with X-Lomiri-Touch=true in .desktop files of a few applications.
And, even I don't understand why, it has worked, there were no lags anymore !

I just replaced X-Lomiri-Touch=true by #X-Lomiri-Touch=true, nothing more.

So I wonder :

Are X-Lomiri-* specific desktop entries documented somewhere ?
Why X-Lomiri-Touch=true can cause lags on some phones ?

arubislander

@eheintzmann Could you add to your post which phone is 'this phone'?

Eric H

@arubislander Xiaomi Poco X3 NFC (surya)

danfro

Are those apps where you commented out that line build for focal? Or do you have some xenial apps running that do still work under focal?

Eric H

@danfro Hi
During my tests, I commented out core applications only :

ciborium.desktop
content-hub-send.desktop
dialer-app.desktop
lomiri-system-settings.desktop
lomiri.desktop
mediaplayer-app.desktop
messaging-app.desktop
morph-browser.desktop

TheKit

I think this issue is related to https://gitlab.com/ubports/development/core/lomiri-app-launch/-/merge_requests/47#note_1567842127. As I understand from the discussion, if lomiri-app-launch is unable to write oom_adj values, it will attempt to spawn an OOM SUID helper, and doing so for every thread takes lot of time/resources.

The easiest workaround for now is to revert Android commits in the device port kernel that made read-only oom_adj (as they had been also discarded upstream):
https://gitlab.com/ubports/porting/community-ports/android10/xiaomi-redmi-note-9-pro/kernel-xiaomi-sm6250/-/commit/d13041168eae01e79e9625f280a640ab8f960033
https://gitlab.com/ubports/porting/community-ports/android10/xiaomi-redmi-note-9-pro/kernel-xiaomi-sm6250/-/commit/c45ed3b1cdf7d8e485bb4b50dfd1ec9842b4bd64

Eric H

@TheKit thanks
@ywmaa I'm going to try that on the surya kernel

Eric H

@TheKit
I tested your solution.
It just works.
Many thanks.

Eric H

@TheKit
Your fix has been applied on surya kernel by @ywmaa.
Users have reported on Telegram that UI freeze are gone.