Experiences about compiling & packaging on-device.

Compiling & packaging with Harmattan SDK using command "dpkg-buildpackage -sa -rfakeroot". Nokia N9 used the image of section 2b above. Time in seconds (s) :

python-sympy 0.7.1 (pure Python package) : XPS 15 (42s), A1215B (180s), N9 (94s);

easy-chroot 0.2.0 (package with scripts) : XPS 15 (14s), A1215B (44s), N9 (60s);

blas 1.2 (package with a lot of C & Fortran compilation) : XPS 15 (1,127s), A1215B (1,971s), N9 (1,118s).

Hardware descriptions :
XPS 15 : Dell XPS 15 L502X, Core i7 2670QM 4 cores @ 2.2-3.1 GHz, 1+6 MB cache L2/L3, 8GB RAM DDR3 1,333 MHz, 1TB 5,400 RPM SATA hard drive;
A1215B : Asus 1215B, AMD C-50 2 cores @ 1.0GHz, 1 MB cache L2, 2GB RAM DDR3 1,066 MHz, 320 GB 5,400 RPM SATA hard drive;
N9 : Nokia N9, TI OMAP 3630 ARM Cortex A8 @ 1.0 GHz, 1GB RAM mobile DDR.
PS : the notebook's bottleneck is the hard disk, while the N9 has flash memory.

So we see that on-device (N9) compiling and/or packaging is very practical : between not too slow to sometimes faster than netbooks, low-price notebooks and even high-spec notebooks !

More timing when compiling & packaging with chrooted Harmattan SDK on Nokia N9 :

- SciPy 0.14.0 (package with Python, C/C++ and Fortran compilation) : 8,946s (without Python 3 and docs);
- SuiteSparse 3.4.0 (package with Python, C/C++ and Fortran compilation) : 3,889s;
- cython 0.19.1 (package with Python and C/C++ compilation) : 2,168 s (without Python 3 and docs);
- NumPy 1.9.0 (package with Python, C/C++ and Fortran compilation) : 2,294s (without Python 3 and docs);
- MatPlotLib 1.2.0 (package with Python and C/C++ compilation) : 792 s (without Python 3, dbg and HTML/PDF docs);
- zeromq 2.2.0 (package with C/C++ compilation) : 456 s;
- libpgm 5.1.118 (package with C/C++ compilation) : 353 s;
- python-zmq 2.2.0 (package with Python and C/C++ compilation) : 294 s (without Python 3);
- IPython 0.13.1-2 (package with Python) : 132 s (without Python 3);
- python-tornado 2.4.1 (package with Python) : 45 s (without Python 3).

Kernel compilation by jackburton with chrooted Harmattan SDK on Nokia N9 : 5,035 s.