genode/repos/base-okl4
Martin Stein 8f9355b360 thread API & CPU session: accounting of CPU quota
In the init configuration one can configure the donation of CPU time via
'resource' tags that have the attribute 'name' set to "CPU" and the
attribute 'quantum' set to the percentage of CPU quota that init shall
donate. The pattern is the same as when donating RAM quota.

! <start name="test">
!   <resource name="CPU" quantum="75"/>
! </start>

This would cause init to try donating 75% of its CPU quota to the child
"test".  Init and core do not preserve CPU quota for their own
requirements by default as it is done with RAM quota.

The CPU quota that a process owns can be applied through the thread
constructor. The constructor has been enhanced by an argument that
indicates the percentage of the programs CPU quota that shall be granted
to the new thread. So 'Thread(33, "test")' would cause the backing CPU
session to try to grant 33% of the programs CPU quota to the thread
"test". By now, the CPU quota of a thread can't be altered after
construction. Constructing a thread with CPU quota 0 doesn't mean the
thread gets never scheduled but that the thread has no guaranty to receive
CPU time. Such threads have to live with excess CPU time.

Threads that already existed in the official repositories of Genode were
adapted in the way that they receive a quota of 0.

This commit also provides a run test 'cpu_quota' in base-hw (the only
kernel that applies the CPU-quota scheme currently). The test basically
runs three threads with different physical CPU quota. The threads simply
count for 30 seconds each and the test then checks wether the counter
values relate to the CPU-quota distribution.

fix #1275
2014-11-28 12:02:37 +01:00
..
contrib/generated Move repositories to 'repos/' subdirectory 2014-05-14 16:08:00 +02:00
doc Move repositories to 'repos/' subdirectory 2014-05-14 16:08:00 +02:00
etc Move repositories to 'repos/' subdirectory 2014-05-14 16:08:00 +02:00
include base: introduce caching attributes (fix #1184) 2014-06-26 10:57:26 +02:00
lib/mk base: interface for D- and I-cache synchronization 2014-05-27 11:14:45 +02:00
mk okl4: consider elfweaver in cleanall rule 2014-07-09 16:26:06 +02:00
patches okl4: declare read-write-lock as volatile 2014-11-20 16:39:16 +01:00
ports Enable hash checks for ports mechanism 2014-05-27 13:45:03 +02:00
run okl4: fix success condition in priority test 2014-11-12 14:44:16 +01:00
src thread API & CPU session: accounting of CPU quota 2014-11-28 12:02:37 +01:00
tool Move repositories to 'repos/' subdirectory 2014-05-14 16:08:00 +02:00
Makefile Enable hash checks for ports mechanism 2014-05-27 13:45:03 +02:00
README Move repositories to 'repos/' subdirectory 2014-05-14 16:08:00 +02:00

This repository contains the implementation of Genode for the OKL4
kernel version 2.1.  For further information, please refer to the
following documents:

:[http://genode.org/community/wiki/GenodeOnOKL4 - Genode on OKL4 Wiki page]:
  This Wiki page contains the information on how to build and use
  Genode with OKL4.

:[http://genode.org/documentation/articles/genode-on-okl4 - Bringing Genode to OKL4]:
  This article explains the OKL4-specific porting work.