The XO is a low resource environment. There isn't much room to spare for extra memory or compute cycles. This page will be used to identify applications, services, packaging, and kernel tunables that can be modified to improve XO system performance.
Activities include:
- Identifying/testing various service configuration settings
- Making recommendations for Live CD spin kickstart changes to reflect findings
- Kernel tunables?
- Recommended SD installation options?
- Recommended boot-time options?
- Improved desktop performance?
Service Run-level Changes
What system daemons are started that aren't needed? For example, bluetooth ... there is no bluetooth hardware on the XO.
GNOME Desktop Session Changes
Kernel tunables?
- I haven't actually tried this yet, but should look at /proc/sys/vm/swappiness which defaults to 60. Setting to 0 might be best to do as little pre-emptive swapping as possible.
Packaging Changes
Replace firefox with something more light weight?
Looks like epiphany might save a little memory:
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND liveuser 3678 0.1 0.5 4804 1264 ? S 11:08 0:00 /bin/sh /usr/lib/firefox-3.0.2/run-mozilla.sh /usr/lib/firefox-3.0.2/firefox liveuser 3695 31.5 18.5 162356 43436 ? Sl 11:08 0:34 /usr/lib/firefox-3.0.2/firefox
versus
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND liveuser 3740 18.5 15.9 148828 37216 ? Sl 11:11 0:10 epiphany
Image Generation
Overlay Storage
Using the --overlay-size-mb parameter to the livecd-iso-to-disk script is recommended for 2 reasons.
- Any changes to your live image are saved to the SD card (instead of memory). These changes will remain upon reboot.
- It improves performance because there ends up being less memory pressure.
A potential drawback might be that more writes are happening to your SD media, which may lower the life expectancy of the SD media.
Swap space?
If you need to add swap after booting your XO, I've been using the following commands:
# mount /dev/live /mnt/live # dd if=/dev/zero of=/mnt/live/swap.img bs=1024 count=256000 # mkswap /mnt/live/swap.img # swapon /mnt/live/swap.img