Friday, September 08, 2006
A weird effect of discover (SoC2006)
It is funny to see that when I remove discover (/etc/rcS.d/S36discover) from the boot, a disk utilisation and cpu usage peak appear at the end of loading KDE. Would it be that discover is loaded by KDE if it wasn't loaded? Or a discover ghost :p. Well, the bootcharts for the two different cases are available here.
Prelinking during the boot (SoC2006)
I've tried prelinking with the aim of making the boot faster. I've used the package of prelink from debian in unstable and we get no significant time improvement. Prelinking was added after readahead in a custom script run during the boot in /etc/rcS.d/S70prelink. What the script does is to prelink: kdeinit, Xorg, kwin, kdesktop, kicker, artsd, kaccess, ktip, klipper and korgac. The bootcharts are availabe here.
8 second reduction (SoC2006)
By removing useless init-scripts from the symbolic link pool (/etc/rc?.d) we got a further second improvement in the boot time. The two init-scripts removed were hotkey-setup and gdm. The former can be removed as I'm not using a laptop and the latter because I'm using KDE. The boot time was reduced from 46 to 45 seconds. See the new bootchart and compare with the reference bootchart.
Trying to integrate Ubuntu's readahead (SoC2006).
I've been playing a bit with Ubuntu's readahead to get a better boot time on debian. At least they seem to get it. I've used strace to get the list of files for different init-scripts and generate the required /etc/readahead/boot file - containing the files to load to memory. The advantage of readahead over preload so far is that it does not affect the boot time when it is not active. I consider readahead inactive when the boot file is empty and preload when the preload script is removed from the symbolic link pools (/etc/rcX.d).
By using readahead shortly after the system starts to boot (near udev), the boot time is even increased by 2 seconds (e.g. S03readahead in /etc/rcS.d). On the other side, by using some of the files used by KDE during startup there is almost a one second improvement as may be seen in the bootchart. We use readahead in /etc/rcS.d position S42. The list of files and the bootcharts may be found here.
Besides, I've corrected the deliverable 5 including the fact that lintian incorporates now a check for lsb compliance based on our patch! The deliverable is available here
By using readahead shortly after the system starts to boot (near udev), the boot time is even increased by 2 seconds (e.g. S03readahead in /etc/rcS.d). On the other side, by using some of the files used by KDE during startup there is almost a one second improvement as may be seen in the bootchart. We use readahead in /etc/rcS.d position S42. The list of files and the bootcharts may be found here.
Besides, I've corrected the deliverable 5 including the fact that lintian incorporates now a check for lsb compliance based on our patch! The deliverable is available here
Tuesday, September 05, 2006
7 seconds less on the boot time (SoC2006)
With the alioth sever down, it seems our project webpage is down as well. Anyway, we are currently on a 7 second improvement of the boot time by using reordering, dash as /bin/sh and hwclock in the background. The bootchart is available here while that of the original system here. No time was won using preload 0.4 with varied configuration combinations. Curious to see that the time is 2 seconds more even without preload in the symbolic link farm (/etc/rcX.d) when preload is installed.
