The document discusses different types of CPU scheduling algorithms including preemptive vs. non-preemptive scheduling, first-come first-served (FCFS), shortest job first (SJF), priority scheduling, and round robin (RR) scheduling. It provides examples of how to calculate metrics like waiting time, turnaround time, and response time for each algorithm. It also covers topics like multi-level queues, multiprocessor scheduling, and how preemptive scheduling relates to operating system design.
This Presention contains Cpu scheduling algorithms,Scheduling Criteria,process sychroization,mutilevel feed back que,critical section problem anad semaphores,Synchoroniztion hardware
Task scheduling is needed to maintain every process that comes with a processor in parallel processing. In several conditions, not every algorithm works better on the significant problem. Sometimes FCFS algorithm is better than the other in short burst time while Round Robin is better for multiple processes in every single time. But we cannot predict what process will come after. Average Waiting Time is a standard measure for giving credit to the scheduling algorithm. Several techniques have been applied to maintain the process in order to make the CPU performance in normal. The objective of this paper is to compare three algorithms, FCFS, SJF and Round Robin. Finally, we know which algorithm is more suitable for the certain process.
This Presention contains Cpu scheduling algorithms,Scheduling Criteria,process sychroization,mutilevel feed back que,critical section problem anad semaphores,Synchoroniztion hardware
Task scheduling is needed to maintain every process that comes with a processor in parallel processing. In several conditions, not every algorithm works better on the significant problem. Sometimes FCFS algorithm is better than the other in short burst time while Round Robin is better for multiple processes in every single time. But we cannot predict what process will come after. Average Waiting Time is a standard measure for giving credit to the scheduling algorithm. Several techniques have been applied to maintain the process in order to make the CPU performance in normal. The objective of this paper is to compare three algorithms, FCFS, SJF and Round Robin. Finally, we know which algorithm is more suitable for the certain process.
Kantara Initiative's UMA Work Group published revision 9 of its OAuth-based protocol on March 6 to solve a broad range of "access management 2.0" challenges, and will shortly begin interoperability testing. On Thursday, March 20, at 8am Pacific, the UMA Work Group conducted a free public webinar sponsored by Kantara board member CA Technologies to discuss UMA's benefits for enterprises. This is a capture of the slides from the webinar. The video can be found at http://bit.ly/1iEs30O
The engineering challenges of designing for low latency execution include tightly controlling the time it takes to detect the onset of latency excursion and a diagnosis of its most likely cause. In modern x-as-a-service (XaaS) forms of distributed applications, the points at which latency is experienced by a service consumer are separated by many layers of modular abstractions from the underlying system hardware. This separation makes it difficult to pinpoint the causes of latency pushouts and to apply corrective actions in a timely manner. The classic performance methodology to profile ‘cycles’ of work may be broadly successful in extracting higher levels of latency, but not very effective in determining causes of short-duration latency surges; and, to determine that, it is frequently necessary to:
• trace execution
• pinpoint when a significant latency stretch out occurs
• establish its correlation with a nearby precursor or a set of precursor events
Each of these steps can incur significant overheads; further, one has to be concerned that even modest overheads from tracing risk contributing to tail latencies. Not just the detection of the onset of a latency excursion, but the identification of why it occurs must be completed quickly so that if a corrective action is possible, it can be taken promptly. Similarly, if no recourse to curb the latency of a slice of computation is available at some point in time, then it is ideal that steps to minimize the impact of the exception are put into effect as early as possible
In our talk, we present an approach that complements the very low overhead software tracing provided by KUtrace. It uses eBPF to trigger a collection of additional data at very low overhead from the hardware performance monitoring unit (PMU) so that latency excursions within a span of execution can be examined in a timely manner. We will describe the use of PMU capabilities like precise events-based sampling (PEBS) and timed last branch records (Timed LBRs) in close proximity to events of interest to extract critical clues. We will further discuss planned future work to integrate in-band network telemetry (INT) into these tracing flows.
"Session ID: BUD17-309
Session Name: IRQ prediction - BUD17-309
Speaker: Daniel Lezcano
Track: Power Management
★ Session Summary ★
The CPUidle is one component of the power management framework. It behaves in an opportunistic way when there is nothing to do on the system, by trying to predict the next CPU wake up and select an idle state. But the current design has some weaknesses as it mixes the different sources of wakeup, resulting in an already non-deterministic situation getting worse. This presentation will describe the issues faced with the current approach and will show another approach to predict the next wake up event with a better accuracy, leading, under some circumstances, to 100% right predictions.
---------------------------------------------------
★ Resources ★
Event Page: http://connect.linaro.org/resource/bud17/bud17-309/
Presentation: https://www.slideshare.net/linaroorg/bud17309-irq-prediction
Video: https://youtu.be/krFAyi1ietI
---------------------------------------------------
★ Event Details ★
Linaro Connect Budapest 2017 (BUD17)
6-10 March 2017
Corinthia Hotel, Budapest,
Erzsébet krt. 43-49,
1073 Hungary
---------------------------------------------------
Keyword: IRQ, power-management, CPUidle
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In operating system concepts, the scheduling algorithm identifies and schedules the jobs in the queue. It is classified into Preemptive and Non-Preemptive algorithms. The different types of scheduling algorithms includes FCFS, SJF, SJRTF , Round robin and Priority scheduling. This PPT explains the concepts of CPU Scheduling Algorithms with simple examples.
Operating Systems Process Scheduling Algorithmssathish sak
CPU scheduling big area of research in early ‘70s
Many implicit assumptions for CPU scheduling:
One program per user
One thread per program
Programs are independent
These are unrealistic but simplify the problem
Does “fair” mean fairness among users or programs?
If I run one compilation job and you run five, do you get five times as much CPU?
Often times, yes!
Goal: dole out CPU time to optimize some desired parameters of the system.
Enterprise Excellence is Inclusive Excellence.pdfKaiNexus
Enterprise excellence and inclusive excellence are closely linked, and real-world challenges have shown that both are essential to the success of any organization. To achieve enterprise excellence, organizations must focus on improving their operations and processes while creating an inclusive environment that engages everyone. In this interactive session, the facilitator will highlight commonly established business practices and how they limit our ability to engage everyone every day. More importantly, though, participants will likely gain increased awareness of what we can do differently to maximize enterprise excellence through deliberate inclusion.
What is Enterprise Excellence?
Enterprise Excellence is a holistic approach that's aimed at achieving world-class performance across all aspects of the organization.
What might I learn?
A way to engage all in creating Inclusive Excellence. Lessons from the US military and their parallels to the story of Harry Potter. How belt systems and CI teams can destroy inclusive practices. How leadership language invites people to the party. There are three things leaders can do to engage everyone every day: maximizing psychological safety to create environments where folks learn, contribute, and challenge the status quo.
Who might benefit? Anyone and everyone leading folks from the shop floor to top floor.
Dr. William Harvey is a seasoned Operations Leader with extensive experience in chemical processing, manufacturing, and operations management. At Michelman, he currently oversees multiple sites, leading teams in strategic planning and coaching/practicing continuous improvement. William is set to start his eighth year of teaching at the University of Cincinnati where he teaches marketing, finance, and management. William holds various certifications in change management, quality, leadership, operational excellence, team building, and DiSC, among others.
Cracking the Workplace Discipline Code Main.pptxWorkforce Group
Cultivating and maintaining discipline within teams is a critical differentiator for successful organisations.
Forward-thinking leaders and business managers understand the impact that discipline has on organisational success. A disciplined workforce operates with clarity, focus, and a shared understanding of expectations, ultimately driving better results, optimising productivity, and facilitating seamless collaboration.
Although discipline is not a one-size-fits-all approach, it can help create a work environment that encourages personal growth and accountability rather than solely relying on punitive measures.
In this deck, you will learn the significance of workplace discipline for organisational success. You’ll also learn
• Four (4) workplace discipline methods you should consider
• The best and most practical approach to implementing workplace discipline.
• Three (3) key tips to maintain a disciplined workplace.
Business Valuation Principles for EntrepreneursBen Wann
This insightful presentation is designed to equip entrepreneurs with the essential knowledge and tools needed to accurately value their businesses. Understanding business valuation is crucial for making informed decisions, whether you're seeking investment, planning to sell, or simply want to gauge your company's worth.
The world of search engine optimization (SEO) is buzzing with discussions after Google confirmed that around 2,500 leaked internal documents related to its Search feature are indeed authentic. The revelation has sparked significant concerns within the SEO community. The leaked documents were initially reported by SEO experts Rand Fishkin and Mike King, igniting widespread analysis and discourse. For More Info:- https://news.arihantwebtech.com/search-disrupted-googles-leaked-documents-rock-the-seo-world/
Putting the SPARK into Virtual Training.pptxCynthia Clay
This 60-minute webinar, sponsored by Adobe, was delivered for the Training Mag Network. It explored the five elements of SPARK: Storytelling, Purpose, Action, Relationships, and Kudos. Knowing how to tell a well-structured story is key to building long-term memory. Stating a clear purpose that doesn't take away from the discovery learning process is critical. Ensuring that people move from theory to practical application is imperative. Creating strong social learning is the key to commitment and engagement. Validating and affirming participants' comments is the way to create a positive learning environment.
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"𝑩𝑬𝑮𝑼𝑵 𝑾𝑰𝑻𝑯 𝑻𝑱 𝑰𝑺 𝑯𝑨𝑳𝑭 𝑫𝑶𝑵𝑬"
𝐓𝐉 𝐂𝐨𝐦𝐬 (𝐓𝐉 𝐂𝐨𝐦𝐦𝐮𝐧𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬) is a professional event agency that includes experts in the event-organizing market in Vietnam, Korea, and ASEAN countries. We provide unlimited types of events from Music concerts, Fan meetings, and Culture festivals to Corporate events, Internal company events, Golf tournaments, MICE events, and Exhibitions.
𝐓𝐉 𝐂𝐨𝐦𝐬 provides unlimited package services including such as Event organizing, Event planning, Event production, Manpower, PR marketing, Design 2D/3D, VIP protocols, Interpreter agency, etc.
Sports events - Golf competitions/billiards competitions/company sports events: dynamic and challenging
⭐ 𝐅𝐞𝐚𝐭𝐮𝐫𝐞𝐝 𝐩𝐫𝐨𝐣𝐞𝐜𝐭𝐬:
➢ 2024 BAEKHYUN [Lonsdaleite] IN HO CHI MINH
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➢CHILDREN ART EXHIBITION 2024: BEYOND BARRIERS
➢ WOW K-Music Festival 2023
➢ Winner [CROSS] Tour in HCM
➢ Super Show 9 in HCM with Super Junior
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➢ Vietnam Food Expo with Lotte Wellfood
"𝐄𝐯𝐞𝐫𝐲 𝐞𝐯𝐞𝐧𝐭 𝐢𝐬 𝐚 𝐬𝐭𝐨𝐫𝐲, 𝐚 𝐬𝐩𝐞𝐜𝐢𝐚𝐥 𝐣𝐨𝐮𝐫𝐧𝐞𝐲. 𝐖𝐞 𝐚𝐥𝐰𝐚𝐲𝐬 𝐛𝐞𝐥𝐢𝐞𝐯𝐞 𝐭𝐡𝐚𝐭 𝐬𝐡𝐨𝐫𝐭𝐥𝐲 𝐲𝐨𝐮 𝐰𝐢𝐥𝐥 𝐛𝐞 𝐚 𝐩𝐚𝐫𝐭 𝐨𝐟 𝐨𝐮𝐫 𝐬𝐭𝐨𝐫𝐢𝐞𝐬."
RMD24 | Retail media: hoe zet je dit in als je geen AH of Unilever bent? Heid...BBPMedia1
Grote partijen zijn al een tijdje onderweg met retail media. Ondertussen worden in dit domein ook de kansen zichtbaar voor andere spelers in de markt. Maar met die kansen ontstaan ook vragen: Zelf retail media worden of erop adverteren? In welke fase van de funnel past het en hoe integreer je het in een mediaplan? Wat is nu precies het verschil met marketplaces en Programmatic ads? In dit half uur beslechten we de dilemma's en krijg je antwoorden op wanneer het voor jou tijd is om de volgende stap te zetten.
B2B payments are rapidly changing. Find out the 5 key questions you need to be asking yourself to be sure you are mastering B2B payments today. Learn more at www.BlueSnap.com.
3.0 Project 2_ Developing My Brand Identity Kit.pptxtanyjahb
A personal brand exploration presentation summarizes an individual's unique qualities and goals, covering strengths, values, passions, and target audience. It helps individuals understand what makes them stand out, their desired image, and how they aim to achieve it.
Implicitly or explicitly all competing businesses employ a strategy to select a mix
of marketing resources. Formulating such competitive strategies fundamentally
involves recognizing relationships between elements of the marketing mix (e.g.,
price and product quality), as well as assessing competitive and market conditions
(i.e., industry structure in the language of economics).
1. Preemptive vs. Non-preemptive
Chapter 6: CPU Scheduling
Scheduling
• Always want to have CPU working • Non-preemptive scheduling
• Usually many processes in ready queue – A new process is selected to run either
– Ready to run on CPU • when a process terminates or
– Consider a single CPU here • when an explicit system request causes a wait state
(e.g., I/O or wait for child)
• Need strategies
• Preemptive scheduling
– Selecting next process to run
– For allocating CPU time – New process selected to run also when
– What happens after a process does a system call? • An interrupt occurs
• Short-term scheduling • When new processes become ready
– Must not take much CPU time
Performance Criteria Scheduling Algorithms
• CPU utilization • First-come, First-Served (FCFS)
– Percentage of time that CPU is busy (and not idle), over – Complete the jobs in order of arrival
some period of time
• Shortest Job First (SJF)
• Throughput
– Complete the job with shortest next CPU requirement
– Number of jobs completed per unit time (e.g., burst)
• Turnaround time – Provably optimal w.r.t. average waiting time
– Time interval from submission of a process until • Priority
completion of the process
– Processes have a priority number
• Waiting time – Allocate CPU to process with highest priority
– Sum of the time periods spent in the ready queue
• Round-Robin (RR)
• Response time – Each process gets a small unit of time on CPU (time
– Time from submission until first output/input quantum or time slice)
– May approximate by time from submission until first – For now, assume a FIFO queue of processes
access to CPU
FCFS: First-Come First-Served Solution: Gantt Chart Method
P1 P2 P3 P4 P5
• Implement with a FIFO ready queue
20 32 40 56 60
• Major disadvantage can be long wait times
• Example • Waiting times:
• P1: 0
– Draw Gantt chart
• P2: 20
– Compute the average wait time for processes
• P3: 32
with the following burst times and queue order:
• P4: 40
• P1: 20, P2: 12, P3: 8, P4: 16, P5: 4
• P5: 56
• Average wait time: 29.6
1
2. SJF: Shortest Job First SJF Solution
P5 P3 P2 P4 P1
• The job with the shortest next CPU burst
4 12 24 40 60
time is selected
• Example (from before): • Waiting times:
– CPU job burst times: • P1: 40
• P1: 20, P2: 12, P3: 8, P4: 16, P5: 4 • P2: 12
– Draw Gantt chart and compute the average • P3: 4
waiting time given SJF CPU scheduling • P4: 24
• P5: 0
• Average wait time: 16
SJF Example Estimate
• Provably shortest average wait time
Say, α = 0.5
• However, requires future knowledge •
τ0 = 10
• May have an estimate, to predict next CPU burst •
– E.g., base on last CPU burst and a number summarizing
• CPU burst, t = 6
history of CPU bursts
τn+1 = α * t + (1 - α) * τn • What is estimate of next CPU burst?
– Where t is the last CPU burst value, α is a constant τ1 = 0.5 * 6 + 0.5 * 10 = 8
indicating how much to base estimate on last CPU
burst, and τn is the last estimate
Which Scheduling Algorithms
Priority Scheduling
Can be Preemptive?
• Have to decide on a numbering scheme
– 0 can be highest or lowest
• FCFS (First-come, First-Served)
• FCFS as priority: all have equal priorities
– Non-preemptive
• SJF as priority: priority is reciprocal of predicted
• SJF (Shortest Job First)
CPU burst
– Can be either
• Priorities can be
– Choice when a new job arrives
– Internal
– Can preempt or not
• according to O/S factors (e.g., memory requirements)
– External: e.g., User importance • Priority
– Static: fixed for the duration of the process – Can be either
– Dynamic – Choice when a processes priority changes or when a
higher priority process arrives
• Changing during processing
• E.g., as a function of amount of CPU usage, or length of time
waiting (a solution to indefinite blocking or starvation)
2
3. RR (Round Robin) Scheduling Solution
completes
completes completes completes completes
• Give each process a unit of time (time slice,
quantum) of execution on CPU P1 P2 P3 P4 P5 P1 P2 P3 P4 P1 P2 P4 P1 P4 P1
• Then move to next process 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60
• Waiting times:
• Continue until all processes completed
• P1: 16 + 12 + 8 + 4 = 40
• Example
• P2: 4 + 16 + 12 = 32
– CPU job burst times & order in queue
• P3: 8 + 16 = 24
• P1: 20, P2: 12, P3: 8, P4: 16, P5: 4
• P4: 12 + 16 + 8 = 36
– Draw Gantt chart, and compute average wait time
• P5: 16
• Average wait time: 29.6
Calculate Other Measurements
Response Time Calculations
• Response time
– Estimate by time from job submission to time to first
CPU dispatch Job FCFS SJF RR
– Assume all jobs submitted at same time, in order given
P1 0 40 0
• Turnaround time
– Time interval from submission of a process until
P2 20 12 4
completion of the process
FCFS P3 32 4 8
P1 P2 P3 P4 P5
20 32 40 56 60
P4 40 24 12
SJF P5 P3 P2 P4 P1
P5 56 0 16
4 12 24 40 60
Average 29.6 16 8
RR P1 P2 P3 P4 P5 P1 P2 P3 P4 P1 P2 P4 P1 P4 P1
4 8 12 16 20 24 28 32 36 40 44 48 52 56 60
Performance Characterstics of
Turnaround Time Calculations
Scheduling Algorithms
Job FCFS SJF RR
P1 20 60 60 • Different algorithms will have different
performance characteristics
P2 32 24 44
• RR (Round Robin)
P3 40 12 32 – Good average response time
• Important for interactive or timesharing systems
P4 56 40 48
• SJF
P5 60 4 20 – Best average waiting time
– Some overhead w.r.t. estimates of CPU burst length
Average 41.6 28 40.8
Assume processes submitted at same time
3
4. Context Switching Issues Example
• These calculations have not taken context switch • Calculate average wait time for RR (round
duration into account
robin) scheduling, for
– In general, the context switch will take time
– Processes: P1: 24, P2: 4, P3: 4
– Just like the CPU burst of a process takes time
– Assume this arrival order
– Response time, wait time etc. will be affected by
context switch time
– Quantum = 4; context switch time = 1
• RR (Round Robin) & quantum duration
– The smaller the time quantum, the better the average
response time, but the more system overhead
– Want the quantum large compared to context switch
time
Solution: Average Wait Time
Multi-level Ready Queues
With Context Switch Time
• Multiple ready queues
P1 P2 P3 P1 P1 P1 P1 P1 – For different types of processes (e.g., system, vs. user
processes)
45 9 10 14 15 19 20 24 25 29 30 34 35 39
– For different priority processes (e.g., Mach)
• P1: 0 + 11 + 4 = 15
• Each queue can
• P2: 5
– Have a different scheduling algorithm
• P3:10
– Receive a different amount of CPU time
• Average: 10 – Have movement of processes to another queue
(feedback);
• e.g., if a process uses too much CPU time, put in a lower
(This is a case for dynamically varying the priority queue
time quantum, as in Mach.) • If a process is getting too little CPU time, put it in a higher
priority queue
Synchronization Issues
Multiprocessor Scheduling
• Symmetric multiprocessing
• When a computer has more than one processor, • Involves synchronization of access to global ready
need a method of dispatching processes queue
• Types of ready queues – E.g., only one processor must execute a job at one time
– Local: dispatch to a specific processor
• Processors: CPU1, CPU2, CPU3, …
– Global: dispatch to any processor (“load sharing”)
• When a processor (e.g., CPU1) accesses the ready
• Processor/process relationship queue
– Run on only a specific processor (e.g., if it must use a – All other processors (CPU2, CPU3, …) must wait, and
device on that processor’s private bus) be denied access to the ready queue
– Run on any processor – The accessing processor (e.g., CPU1) will remove a
• Symmetric: Each processor does own scheduling process from the ready, and dispatch it on itself
– Then that processor will make the ready queue
• Master/slave:
available for use by the other CPU’s (CPU2, CPU3, …)
– Master processor dispatches processes to slaves
4
5. Pre-emptive Scheduling &
Operating System Design
• With pre-emptive CPU scheduling, a new process
can run when interrupt occurs
• What if thread A was in the middle of updating
data structures, and was put back in ready queue
– Either on disk or in shared memory
• If thread B also accesses same data structures
– May access data structures in an inconsistent state
• Need mechanisms for cooperative data access
– Both in Kernel
• Kernel, in general, needs to handle interrupts
• Don’t want to loose interrupts
• Real-time & multi-processor issues
• May need preemption in the kernel itself
– And by multiple processes/threads
5