- Status Unconfirmed
- Task Type Bug Report
- Category Core
- Operating System Release 1 (Zaxxon)
- Severity Medium
- Reported Version SuperZaxxon Final 1.54
FS#331 - Hold switch key continuously sends X11 KeyPress events to active application, increasing CPU usage
When put into Hold mode, X11 handles the power switch as if it's being pressed, and it generates lots of keypress events, passing them to the foreground application. Since /dev/input/eventX does not seem to continuously trigger, I'm guessing it's due to key repeat.
- Install xev and open it in the terminal
- Put the power key in HOLD mode
- Notice the "time" value changing rapidly
In addition to causing more work to X, it also floods the active application with key presses, resulting in increased CPU usage. In my test, switching to HOLD while Firefox is in the foreground causes it to use 6% CPU and X an additional 2.5%.
In addition, the key-press events continue even after the switch is taken off HOLD until another key is pressed.
A possible solution to this is to blacklist the power-button event device, to prevent evdev from listening to it (the key is handled by pndevmapperd).