Ubuntu 22.04下Bash终端卡顿及gnome-shell高内存占用问题排查求助

Hey there, let's tackle both your slow Bash terminal and the high memory usage from gnome-shell step by step. I'll share practical troubleshooting checks tailored to your Ubuntu 22.04 setup:

一、排查Bash终端卡顿问题（针对自动补全/搜索怀疑） #

Since you suspect auto-completion or search might be the culprit, let's start here:

• Test a clean Bash environment
  Run bash --noprofile --norc to launch a Bash session without loading any custom configs or completion scripts. If the terminal feels snappier now, the issue is definitely in your shell configuration files.
• Isolate problematic configs
  Rename your main Bash config to test: mv ~/.bashrc ~/.bashrc.bak, then restart the terminal. If it's fast, gradually restore sections of the original .bashrc (copy lines back one by one) to pinpoint which part is causing the slowdown—look for custom completion functions, aliases that run heavy commands, or history-related tweaks.
• Check bash-completion scripts
  System-wide completion scripts live in /etc/bash_completion.d/. You can temporarily disable all system completions by commenting out the line that sources /etc/bash_completion in your .bashrc, then test again. If that fixes it, try removing or renaming individual scripts in that directory to find the problematic one.
• Inspect history settings
  A huge history file can slow down search/auto-completion. Check your current HISTSIZE and HISTFILESIZE values with echo $HISTSIZE $HISTFILESIZE. If they're set to very large numbers (like 10000+), try temporarily setting them to smaller values (e.g., HISTSIZE=1000) and see if the terminal speeds up.
• Monitor CPU usage during terminal actions
  Open htop in another window, then perform actions that trigger the slowdown (like pressing Tab for auto-completion). Watch if any process (including bash) spikes to high CPU usage—this can point to a resource-heavy script running in the background.

二、排查gnome-shell高内存占用问题 #

5.4GB virtual memory with 244MB active isn't catastrophic, but if it's growing over time or causing issues, let's dig in:

• Track gnome-shell resource usage in real-time
  Run top -p $(pgrep gnome-shell) to focus only on the gnome-shell process. Watch the RES (resident memory) column—if it keeps increasing over hours without you opening new apps, that's a sign of a memory leak.
• Verify installed extensions (even if you think none are present)
  Ubuntu 22.04 comes with some default extensions enabled. List all extensions with gnome-extensions list. Try disabling them one by one with gnome-extensions disable <extension-name>, then check if memory usage drops. For example, common suspects include ubuntu-dock@ubuntu.com or desktop-icons@csoriano—test disabling these temporarily.
• Check gnome-shell logs for errors
  Run journalctl -u gnome-shell.service -f to stream real-time logs from gnome-shell. Look for repeated error messages or warnings—these often indicate bugs or misconfigurations that cause memory leaks. If you see a pattern of the same error looping, that's likely the culprit.
• Reset gnome-shell to default settings
  Backup your current config first: dconf dump /org/gnome/shell/ > ~/gnome-shell-backup.dconf. Then reset all shell settings with dconf reset -f /org/gnome/shell/. Press Alt+F2, type r, and press Enter to restart gnome-shell. Check if memory usage returns to a normal level.
• Ensure your system is fully updated
  Run sudo apt update && sudo apt upgrade to install the latest patches and bug fixes. Many gnome-shell memory leak issues are resolved in newer updates, so this is a quick win worth trying.

Start with the simplest checks first (like testing clean Bash or updating the system) and work your way up. Let me know which step gives you clues about the root cause!

备注：内容来源于stack exchange，提问作者FourierFlux