iLiad The iLiad boot process

[jharker]

Hey, folks. I recently read about the five-second boot presented at the Linux Plumbers Conference. It got me thinking about doing something similar for the iLiad. As a first step, I got a copy of Bootchart and set it up to run on my iLiad during boot. I clocked my iLiad at about 52 seconds, from flipping the power switch to seeing the ContentLister.

I see a few places where time is apparently wasted, but I think the LPC guys have a good point: the goal isn't to reduce boot speed, it's to set a budget (5 seconds) for boot and then redesign the boot to make it hit the goal.

Anyway, redesigning boot occurs fairly late in our list of milestones, so I don't plan on doing extensive work on this any time soon. I was just curious, and thought you might find it interesting.

BTW, thanks to Adam for providing updated Busybox that helped me get this running. Bootchart also requires a little hacking to get it to run correctly. Thankfully, it's just a shell script, so it's pretty easy to hack.

Anyway, here's the result. Bear in mind that I had to put Bootchart into the init.d scripts to get it to run, so it starts a little bit later than it normally would.

[stonehat]

Good work !

[hansel]

Originally Posted by jharker

[...] the goal isn't to reduce boot speed, it's to set a budget (5 seconds) for boot and then redesign the boot to make it hit the goal.

Nice chart! The 5 secs part will be difficult, since the real bootings only starts after 6 sec?
The cpu is running at 100% almost all the time, so the only possible improvement is skipping things...

What about:

const char *kHz="2000";
fp = fopen("/proc/sys/cpu/0/speed", "w");
if (fp) {
      fputs(kHz, fp);
      fclose(fp);
}

[jharker]

Originally Posted by hansel

Nice chart! The 5 secs part will be difficult, since the real bootings only starts after 6 sec?

Yes, I wondered about that. Achieving 5 secs may be impossible-- or, it may take some kernel and init hacking.

[Mr. Goodbar]

Even if it could get into the twenty second range that would be a great improvement and put it in the range of the cybook.

[Antartica]

Originally Posted by hansel

Nice chart!

I agree :-).

Originally Posted by hansel

The 5 secs part will be difficult, since the real bootings only starts after 6 sec?
The cpu is running at 100% almost all the time, so the only possible improvement is skipping things...

It isn't so bad. After all, ContentLister is started at 25s, and it consumes the time until the end of the chart (well, both contenrLister and mb-applet-icon). If we substitute contentlister with something that needs less libraries (i.e. not based on gtk+, but raw X or just SDL...), we would have an easy 52-25=27 seconds. Assume that the replacement needs 2 seconds, and we would be in 27 seconds boot time .

And we can easily gain a significant number of additional seconds making the init simpler (just one script, no awk, etc.).

So the future is bright

PD: this is consistent with scotty's experiment of launching a java app directly instead of contentlister; he reported that the boot time almost halved

[Mr. Goodbar]

You guys could give the iLiad a whole second life with this type of progress!