Puppy Linux Discussion Forum

[GJones]

First off, I'll admit to being a little unwilling to give Wary (or any kind of Puppy Linux) a try. I do not like the idea of running as root, completely bypassing the UNIX permissions system. However... I have a spare Thinkpad 600E with 192 MB of RAM, and other Linux distros are simply not usable on it. GTK2 applications in particular lag like crazy on most distros, and also on *BSD. Haven't even tried Qt4 applications on that computer, and get a feeling I shouldn't.

After some investigation into GTK2 performance issues on old computers, I decided I had nothing to lose, and tried the latest version of Wary...

And lo and behold, the same applications that were unusable on other distributions worked fine on Wary. The awful menu delays I'd seen elsewhere simply weren't there. Even Seamonkey worked fine - slow, sure, but responsive enough to use for basic browsing. The only unusable application is Abiword, and that's thanks to the smooth scrolling misfeature in 2.8.6, which is a whole other matter.

So, I have to ask: why should a given GTK2 program be faster on Wary than on, say, Debian Squeeze? Are some packages for Wary compiled with optimizations for low-end computers, or with certain features disabled? Can anyone give me details on this?

[jemimah]

I think it's mostly to do with how much crap is running in the background. Wary keeps background daemons to a minimum, for example there's no dbus which surely speeds things up a lot but limits the applications you can have.

[GJones]

Maybe, but I don't think that's it... I had OpenBSD running entirely without dbus, and had tried one Linux distro (a Salix custom install) likewise. Both were still barely usable compared to Wary.

I should also note that the Wary install is frugal, which I'm guessing (though I may be wrong) means additional overhead from decompression. So I'm just kind of stumped at how decent the performance is.

Hmm... What are the default compile options for Wary? -O1? -O2? Also, does anyone have a copy of the Wary kernel config? The config doesn't seem to be present in the distribution, and I'd like to see what changes were made to it from the default.

[jemimah]

As far as I can tell, Barry has never mentioned doing anything special with the gtk compile options. But the community seems to generally agree that things should be compiled -Os with a few other options to reduce binary size.

You can recompile gtk with whatever options you want just to prove if it makes a difference or not - I'm guessing not.

Kernel configs can be found in /etc/modules/DOTconfig-*

If you're running a frugal install, maybe running from RAM explains it, but I would expect that to only boost application start up speed.

Maybe the older version of xorg likes your video hardware better - you could compare wary with racy to see if that's the case.

[izezi]

[GJones]

It's not a big deal from a live CD. Not convinced about live USB though, USB sticks are read/write. For live USB I'd be more inclined to use something like Porteus, I think (it uses a guest account by default).

(Computers that can boot properly from a USB stick are generally powerful enough to handle Porteus anyway.)

BTW I've come up with something:

This page seems to indicate that Puppy's default compile flags include -fomit-frame-pointer. This makes debugging impossible on x86-32, which is bad; but also frees up a register, which should speed things up quite a bit. That might explain what I've seen to at least some extent, since (due to the debugging issue) very few distros ship binaries compiled with -fomit-frame-pointer.

I would have to do some compiling myself to further investigate. Maybe two copies of a custom Puppy spin, one with -fomit-frame-pointer and one without... I don't really want to set aside the (possibly considerable) time for that though.

[GJones]

Hmm, another thing: I was able to find BK's config for (what I think is) the Wary kernel... It like he has "tickless" mode (CONFIG_NO_HZ) undefined (i.e. same as 'nohz=off'). I've never seen that make any serious performance difference on newer computers, but perhaps CONFIG_NO_HZ introduces some latency or something on very old ones?

(He does have CONFIG_HIGH_RES_TIMERS enabled though. Not sure what that would do without CONFIG_NO_HZ. Also, CONFIG_HZ is set to 250 instead of Slackware's 1000, which IIRC might be of some benefit on an old computer where low latency is impossible anyway.)

[GJones]

Hmm... Well there's something I didn't notice, right in front of my nose. Puppy runs Xorg at niceness -1 by default... That could probably make things snappier on an old machine. I think.

[amigo]

"Xorg at niceness -1" -where is that located?