"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.