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1b1fd1e1f9
The new scheduler serves the orthogonal requirements of both high-throughput-oriented scheduling contexts (shortly called fill in the scheduler) and low-latency-oriented scheduling contexts (shortly called claim in the scheduler). Thus it knows two scheduling modes. Every claim owns a CPU-time-quota expressed as percentage of a super period (currently 1 second) and a priority that is absolute as long as the claim has quota left for the current super period. At the end of a super period the quota of all claims gets refreshed. During a super period, the claim mode is dominant as long as any active claim has quota left. Every time this isn't the case, the scheduler switches to scheduling of fills. Fills are scheduled in a simple round robin with identical time slices. Order and time-slices of the fill scheduling are not affected by the super period. Now on thread creation, two arguments, priority and quota are needed. If quota is 0, the new thread participates in CPU scheduling with a fill only. Otherwise he participates with both a claim and a fill. This concept dovetails nicely with Genodes quota based resource management as any process can grant subsets of its own CPU-time and priorities to its child without knowing the global means of CPU-time and priority. The commit also adds a run script that enables an automated unit test of the scheduler implementation. fix #1225
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Genode Operating System Framework
=================================
This is the source tree of the reference implementation of the Genode OS
architecture. For a general overview about the architecture, please refer to
the project's official website:
:Official project website for the Genode OS Framework:
[http://genode.org/documentation/general-overview]
The current implementation can be compiled for 8 different kernels: Linux,
L4ka::Pistachio, L4/Fiasco, OKL4, NOVA, Fiasco.OC, Codezero, and a custom
kernel for running Genode directly on ARM-based hardware. Whereas the Linux
version serves us as development vehicle and enables us to rapidly develop the
generic parts of the system, the actual target platforms of the framework are
microkernels. There is no "perfect" microkernel - and neither should there be
one. If a microkernel pretended to be fit for all use cases, it wouldn't be
"micro". Hence, all microkernels differ in terms of their respective features,
complexity, and supported hardware architectures.
Genode allows the use of each of the kernels listed above with a rich set of
device drivers, protocol stacks, libraries, and applications in a uniform way.
For developers, the framework provides an easy way to target multiple different
kernels instead of tying the development to a particular kernel technology. For
kernel developers, Genode contributes advanced workloads, stress-testing their
kernel, and enabling a variety of application use cases that would not be
possible otherwise. For users and system integrators, it enables the choice of
the kernel that fits best with the requirements at hand for the particular
usage scenario.
Directory overview
##################
The source tree is composed of the following subdirectories:
:'doc':
This directory contains general documentation. Please consider the following
document for a quick guide to get started with the framework:
! doc/getting_started.txt
If you are curious about the ready-to-use components that come with the
framework, please review the components overview:
! doc/components.txt
:'repos':
This directory contains the so-called source-code repositories of Genode.
Please refer to the README file in the 'repos' directory to learn more
about the roles of the individual repositories.
:'tool':
Source-code management tools and scripts. Please refer to the README file
contained in the directory.
Contact
#######
The best way to get in touch with Genode developers and users is the project's
mailing list. Please feel welcome to join in!
:Genode Mailing Lists:
[http://genode.org/community/mailing-lists]