Currently, various standard library operations like os.walk(), os.path.isdir() and os.path.islink() each call stat or lstat which involves a syscall into the kernel. There is no caching since they could conceivably have changed on disk. The result is that for something like the do_package task of the kernel we're spending over two minutes making 868,000 individual stat calls for 23,000 files. This is suboptimal. This patch adds lib/oe/cachedpath.py which are a set of replacement functions for these operations which use cached stat data rather than hitting the kernel each time. It gives a nice performance improvement halving the build time of the kernel do_package. (From OE-Core rev: 556dee0c4d6d8a87c0cddbd2f60fe5917d009f18) Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Poky
Poky is an integration of various components to form a complete prepackaged build system and development environment. It features support for building customised embedded device style images. There are reference demo images featuring a X11/Matchbox/GTK themed UI called Sato. The system supports cross-architecture application development using QEMU emulation and a standalone toolchain and SDK with IDE integration.
Additional information on the specifics of hardware that Poky supports is available in README.hardware. Further hardware support can easily be added in the form of layers which extend the systems capabilities in a modular way.
As an integration layer Poky consists of several upstream projects such as BitBake, OpenEmbedded-Core, Yocto documentation and various sources of information e.g. for the hardware support. Poky is in turn a component of the Yocto Project.
The Yocto Project has extensive documentation about the system including a reference manual which can be found at: http://yoctoproject.org/documentation
OpenEmbedded-Core is a layer containing the core metadata for current versions of OpenEmbedded. It is distro-less (can build a functional image with DISTRO = "") and contains only emulated machine support.
For information about OpenEmbedded, see the OpenEmbedded website: http://www.openembedded.org/
Where to Send Patches
As Poky is an integration repository, patches against the various components should be sent to their respective upstreams.
bitbake: bitbake-devel@lists.openembedded.org
meta-yocto: poky@yoctoproject.org
Most everything else should be sent to the OpenEmbedded Core mailing list. If in doubt, check the oe-core git repository for the content you intend to modify. Before sending, be sure the patches apply cleanly to the current oe-core git repository. openembedded-core@lists.openembedded.org
Note: The scripts directory should be treated with extra care as it is a mix of oe-core and poky-specific files.