修复屏幕撕裂操作后Xorg CPU占用过高问题求助

Hey Dan, sorry to hear you're stuck with this persistent Xorg CPU usage issue after messing with screen tearing fixes. Let's work through this step by step to get your ThinkPad T460 (Ubuntu 20.04 Mate) back to normal.

一、彻底重置Xorg到默认配置 #

Since you only renamed the custom 20-intel.conf to .bak, there might still be residual configurations or cached settings causing trouble. Try these steps:

• First, make sure your backup config isn't still in the Xorg config directory. Move it to a safe place like your home folder:

  sudo mv /usr/share/X11/xorg.conf.d/20-intel.conf.bak ~/xorg-backup/
  # Create the backup folder if it doesn't exist
  mkdir -p ~/xorg-backup/
  

• Check for other custom Xorg configs in both system directories:

  ls /usr/share/X11/xorg.conf.d/
  ls /etc/X11/xorg.conf.d/
  

  Any files you added (not the default ones like 10-quirks.conf, 40-libinput.conf) should be moved to your backup folder too.
• Reconfigure Xorg to reset all settings to default:

  sudo dpkg-reconfigure xserver-xorg
  

  Reboot your system after running this command.

二、深入排查Xorg高CPU的根源 #

If resetting configs doesn't help, let's dig into what's making Xorg work overtime:

• Install and run xrestop to see which X clients are hogging resources:

  sudo apt install xrestop
  xrestop
  

  This tool shows detailed resource usage for every app connected to Xorg—look for any unusual entries with high CPU or request counts.
• Check Xorg logs for errors or leftover config references:

  cat /var/log/Xorg.0.log | grep -E "(WW|EE|intel)"
  

  Look for warnings/errors about Intel graphics or failed config loads—these might point to lingering issues.
• Reinstall the Intel graphics driver to rule out corruption:

  sudo apt reinstall xserver-xorg-video-intel
  

  Reboot after this to ensure the fresh driver loads properly.

三、排除非Xorg配置的潜在问题 #

If the above steps don't fix it, let's check other areas that could cause high CPU, temperature, and battery drain:

• Check for misbehaving system services:

  systemctl list-units --type=service --state=running | sort -k 3
  

  Look for services with high CPU usage. You can also check the system journal for anomalies since boot:

  journalctl -b | grep -i "error|warning"
  

• Verify power management settings:
  In Mate's System Settings > Power Management, make sure you're on "Balanced" or "Power Saver" mode (not "Performance"). Install powertop to identify power-hungry processes/devices:

  sudo apt install powertop
  sudo powertop
  

  Look for processes with high "Wakeups per second" or devices stuck in high-power states.
• Test with an older kernel:
  Sometimes kernel updates introduce graphics driver compatibility issues. Reboot, select Advanced options for Ubuntu in GRUB, and pick an older kernel version. If the problem disappears, the latest kernel might be the culprit—you can stick with the older one until a fix is released.

Let me know if any of these steps help, or if you spot any strange logs/processes that might clue us in on the root cause. We'll get your system running smoothly again!

备注：内容来源于stack exchange，提问作者Dan C