June 27, 2022 Alina Albu, [email protected]TU/e Computer Science, System Architecture and Networking Philips Research Laboratories Eindhoven 1 Philips Research 1st meeting of project EES.5653 Quality of Service for In-Home Digital Networks PROGRESS PROJECT EES.5653 Terminal QoS M.A. Albu
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Philips Research 1st meeting of project EES.5653 29 June 2015 Alina Albu, [email protected] TU/e Computer Science, System Architecture and Networking Philips.
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TU/e Computer Science, System Architecture and NetworkingPhilips Research Laboratories Eindhoven
5Philips Research
1st meeting of project EES.5653
Collaboration with MRM project
• Why MRM?
– QoS related closely to resource management.
– MRM is concerned with resources management aspects in the context of a terminal.
– MRM provides opportunities for inspiration, validation of my work
• Aim MRM:
– provide methods and means for an integrated approach to resource management in multi-resource systems.
• The integrated approach has to meet at least the following requirements:
– The resource management infrastructure should be able to provide resource guarantees to the building blocks of application functionality.
– Individual building blocks should be able to limit or prevent resource insufficiencies, by dealing with insufficient resources in a graceful and predictable way.
TU/e Computer Science, System Architecture and NetworkingPhilips Research Laboratories Eindhoven
6Philips Research
1st meeting of project EES.5653
Collaboration with MRM project Rationale
This leads to the need for developing methods for estimating the necessary of resources for the building blocks of application but also for predicting resources necessary for the composed execution of these blocks.
• Why performance composition? - Just adding clock cycles of the involved components won’t do.
Method for the estimation of the number of context switches occurring during the execution of a streaming application.
• Current experimentation setting:
– HW: Trimedia (TM 1300) • incorporates a media processor for high-performance multimedia applications
TU/e Computer Science, System Architecture and NetworkingPhilips Research Laboratories Eindhoven
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1st meeting of project EES.5653
Reasons for context switch occurrence
• Blocking. The execution of a task blocks because of the following reasons:
o Communication with the PC host (ex: FRead)
o Unfavorable status of the queues:
- input full packets queue (IFPQ) is empty (no input)
- output full packets queue (OFPQ) is full (task cannot output packets for the moment)
- output empty packets queue (OEPQ) is empty (task cannot output packets for the moment)
• Preemption. The execution of a task is preempted by another task with a higher priority.
• Task execution end. The execution of a task with high priority has ended (no preemption or blocking) and the resources are allocated to another task.
TU/e Computer Science, System Architecture and NetworkingPhilips Research Laboratories Eindhoven
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1st meeting of project EES.5653
NCS Estimation MethodProperties of streaming applications executions
• Property1: Running streaming applications, after an initialization phase, adopt a pattern of execution that repeats after a specific interval of time (hyperperiod). The repetitive execution is caused by the differences in the components’ rates of production/consumption of full/empty packets.
• Execution consists of 3 phases: initialization, stable-state, finalization
• => by knowing the NCS occuring during initialization, finalization and during a hyperperiod of the steady-state, we obtain the total NCS
• Property2: When one of the components in the streaming chain is periodic, when other components depend on it in execution, their tasks will execute periodic.
Identify for each component the full packets production rate (FPPR), the full packets consumption rate (FPCR), and the empty packets production rate (EPPR).
Priority FPPR FPCR EPPR T AT CT CEPT (ms)
FRead 90 2.2 2.524
Vdec 70 4.6 17.9 4.5 2
VrendVO 80 16.3 16.3 0.056 32.6
- measurements of components rates and computation times in isolation.
Identify for each component the full packets production rate (FPPR), the full packets consumption rate (FPCR), and the empty packets production rate (EPPR).
Identify for each component the full packets production rate (FPPR), the full packets consumption rate (FPCR), and the empty packets production rate (EPPR).
Identify for each component the full packets production rate (FPPR), the full packets consumption rate (FPCR), and the empty packets production rate (EPPR).
Identify for each component the full packets production rate (FPPR), the full packets consumption rate (FPCR), and the empty packets production rate (EPPR).
TU/e Computer Science, System Architecture and NetworkingPhilips Research Laboratories Eindhoven
17Philips Research
1st meeting of project EES.5653
NCS Estimation Method Step 7 : dependencies between components
Step 7
a - Determine the dependencies in the execution of the components by taking into consideration FPPR, FPCR and EPPR for each component.
b - Determining the dependencies in the execution of the components, leads to determining the period (T(Ti)) of each task Ti on which the components C i are mapped.
VDec:
a - FPPR (VDec) > FPCR (VRendVO) (> = rate higher) => OFPQ (VDec) at stable state is full => OEPQ (VDec) is empty => VDec depends on VRendVO to produce 1 EP so that VDec can produce 1 FP =>
TU/e Computer Science, System Architecture and NetworkingPhilips Research Laboratories Eindhoven
18Philips Research
1st meeting of project EES.5653
NCS Estimation Method Step 7 : dependencies between components
Step 7
a - Determine the dependencies in the execution of the components by taking into consideration FPPR, FPCR and EPPR for each component.
b - Determining the dependencies in the execution of the components, leads to determining the period (T(Ti)) of each task Ti on which the components C i are mapped.
FRead:
a – FPPR (FRead) > FPCR (VDec) (> = rate higher) => OFPQ (FRead) at stable state is full => OEPQ (FRead) is empty => FRead depends on VDec to produce 1 EP so that FRead can produce 1 FP =>
TU/e Computer Science, System Architecture and NetworkingPhilips Research Laboratories Eindhoven
24Philips Research
1st meeting of project EES.5653
NCS Estimation Method Step 9 : NCS due to blocking
Step 9.
Determine the NCS due to blocking.
FRead:
• FRead blocks 4 times for each packet that it delivers due to communication with the PC host and has its period equal with the hyperperiod (because it only gets to deliveres 1 full packet during the hyperperiod after which it blocks until the next hyperperiod) =>
TU/e Computer Science, System Architecture and NetworkingPhilips Research Laboratories Eindhoven
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1st meeting of project EES.5653
NCS Estimation Method Step 9 : NCS due to blocking
Step 9. VDec:
• VDec delivers 1 full packet every time it is activated after which it is blocked. • VDec is activated periodically and that its period fits 4 time during the hyperperiod => • VDec is activated 4 times during the hyperperiod => VDec is blocked 4 times during
Note: Differences come from the fact that we work with averages in the components models which determines an average length for the hyperperiod and an average number of hyperperiods.