The generalization of interrupt objects in the kernel and the use of
C++ polymorphism instead of explicitely checking for special interrupts
within generic code (Cpu_job::_interrupt) enables the registration of
additional interrupts used by the kernel, which are needed for specific
aspects added to the kernel, like ARM hardware virtualization interrupts.
* Introduce generic base class for interrupt objects handled by the kernel
* Derive an interrupt class for those handled by the user-land
* Implement IPI-specific interrupt class
* Implement timer interrupts using the new generic base class
Ref #1405
Until now, one distinct software generated IRQ per cpu was used to
send signals between cpus. As ARM's GIC has 16 software generated
IRQs only, and they need to be partitioned between secure/non-secure
TrustZone world as well as virtual and non-virtual worlds, we should
save them.
Ref #1405
Kernel::Processor was a confusing remnant from the old scheme where we had a
Processor_driver (now Genode::Cpu) and a Processor (now Kernel::Cpu).
This commit also updates the in-code documentation and the variable and
function naming accordingly.
fix#1274
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
Previously, the timer was used to remember the state of the time slices.
This was sufficient before priorities entered the scene as a thread always
received a fresh time slice when he was scheduled away. However, with
priorities this isn't always the case. A thread can be preempted by another
thread due to a higher priority. In this case the low-priority thread must
remember how much time he has consumed from its current time slice because
the timer gets re-programmed. Otherwise, if we have high-priority threads
that block and unblock with high frequency, the head of the next lower
priority would start with a fresh time slice all the time and is never
superseded.
fix#1287
