New significant speedups coming to FreeRunner

[Timo Jyrinki]

Hi,

Just FYI to the community list, as slowness has been one of the
biggest problems with Neo. Quite nice speedups are coming:

http://lists.openmoko.org/pipermail/openmoko-kernel/2010-January/010811.html
(performance testing by Gennady Kupava)

Apparently, and unfortunately, no-one had really questioned Om Inc:s
(who mainly did the kernel work back in the days of the still mostly
used 2.6.29) choices of kernel configuration. Disabling kernel debug
features and pre-empt has resulted eg. these kind of improvements
(from IRC, #openmoko-fi):
- boot time 68.5% of original
- "apt-cache search nano" 20s -> 14.8s
- "emacs -f kill-emacs" 3.8s -> 2.2s

These configuration changes are not yet in andy-tracking (the 2.6.29
kernel still being used in most distros), I don't know what's the
situation in the new om-2.6.32 branch. Together with the quite recent
commit from Thomas White that doubled theoretical glamo speeds (in
practice at least 20% in general), I feel that Neo FreeRunner is not
anymore "terribly slow", but only "slow" by today's standards, which
is quite an improvement. Especially after having been used to the
"terribly slow" general behavior ;)

Please tell if some distro happened to have those disabled already,
and if someone knew about these speedups via the options already - and
please arrange a commit to git.openmoko.org next time! Anyway, this
all goes to show that in a project with limited resources like
Openmoko, especially now that it's completely in the hands of the
community when it comes to Neo FreeRunner development, you have to
have the courage to question anything "suspicious" etc. you are
seeing, not trusting that someone has actually optimized something to
the extent assumed.

If you want to have a quick grab of the new kernel for Debian (or any
distro that loads uImage from a file), I put my compilation of kernel
and modules to http://users.tkk.fi/~tajyrink/moko/kernel_20100108_nodebug_nopreempt/

-Timo, wishing everyone a speedier new year