ac162116b3
The Linux pressure monitoring system helps determine when system resources are being overutilized by measuring how contended the CPU, IO and memory are. This information can be found under /proc/pressure/ which contains 3 files - cpu, memory and io. In each of the files, the format is as follows: some avg10=70.24 avg60=68.52 avg300=69.91 total=3559632828 full avg10=57.59 avg60=58.06 avg300=60.38 total=3300487258 The "some" state of a given resource represents when one or more tasks are delayed on that resource whereas the "full" state represents when all the tasks are delayed. Currently, we only collect data from the "some" state but the "full" data can simply be appended to the log files if neccessary. The "avg10", "avg60" and "avg300" fields represent the average percentage of time runnable tasks were delayed in the last 10, 60 or 300 seconds respectively. The "total" field represents the total time, in microseconds, that some runnable task was delayed on a resource. More information can be found at: https://www.kernel.org/doc/html/latest/accounting/psi.html and in the source code under kernel/sched/psi.c This commit adds functionality to collect and log the "some" CPU, memory and IO pressure. The "avg10", "avg60" and "avg300" fields are logged without change. In place of the "total" field, the difference between the current "total" and the previous sample's "total" is logged, allowing the measurement of pressure in between each polling interval, as was done for /proc/stat data. The log files are stored in: <build_name>/tmp/buildstats/<build_time>/reduced_proc_pressure/{cpu,io,memory}.log mirroring the directory structure of /proc/pressure. If the /proc/pressure directory does not exist or the resource files can't be read/opened, the reduced_proc_pressure directory is not created. (From OE-Core rev: 061931520b8baa7f3a03bf466aa9ec8bf995bc14) Signed-off-by: Aryaman Gupta <aryaman.gupta@windriver.com> Signed-off-by: Randy MacLeod <randy.macleod@windriver.com> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Poky
Poky is an integration of various components to form a pre-packaged build system and development environment which is used as a development and validation tool by the Yocto Project. It features support for building customised embedded style device images and custom containers. There are reference demo images ranging from X11/GTK+ to Weston, commandline and more. The system supports cross-architecture application development using QEMU emulation and a standalone toolchain and SDK suitable for 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 BSP layers which extend the systems capabilities in a modular way. Many layers are available and can be found through the layer index.
As an integration layer Poky consists of several upstream projects such as BitBake, OpenEmbedded-Core, Yocto documentation, the 'meta-yocto' layer which has configuration and hardware support components. These components are all part of the Yocto Project and OpenEmbedded ecosystems.
The Yocto Project has extensive documentation about the system including a reference manual which can be found at https://docs.yoctoproject.org/
OpenEmbedded is the build architecture used by Poky and the Yocto project. For information about OpenEmbedded, see the OpenEmbedded website.
Contribution Guidelines
The project works using a mailing list patch submission process. Patches should be sent to the mailing list for the repository the components originate from (see below). Throughout the Yocto Project, the README files in the component in question should detail where to send patches, who the maintainers are and where bugs should be reported.
A guide to submitting patches to OpenEmbedded is available at:
https://www.openembedded.org/wiki/How_to_submit_a_patch_to_OpenEmbedded
There is good documentation on how to write/format patches at:
https://www.openembedded.org/wiki/Commit_Patch_Message_Guidelines
Where to Send Patches
As Poky is an integration repository (built using a tool called combo-layer), patches against the various components should be sent to their respective upstreams:
OpenEmbedded-Core (files in meta/, meta-selftest/, meta-skeleton/, scripts/):
- Git repository: https://git.openembedded.org/openembedded-core/
- Mailing list: openembedded-core@lists.openembedded.org
BitBake (files in bitbake/):
- Git repository: https://git.openembedded.org/bitbake/
- Mailing list: bitbake-devel@lists.openembedded.org
Documentation (files in documentation/):
- Git repository: https://git.yoctoproject.org/cgit/cgit.cgi/yocto-docs/
- Mailing list: docs@lists.yoctoproject.org
meta-yocto (files in meta-poky/, meta-yocto-bsp/):
- Git repository: https://git.yoctoproject.org/cgit/cgit.cgi/meta-yocto
- Mailing list: poky@lists.yoctoproject.org
If in doubt, check the openembedded-core git repository for the content you intend to modify as most files are from there unless clearly one of the above categories. Before sending, be sure the patches apply cleanly to the current git repository branch in question.