'Reference bit' diaporamas de présentation

CMSC421: Principles of Operating Systems

CMSC421: Principles of Operating Systems. Nilanjan Banerjee. Assistant Professor, University of Maryland Baltimore County nilanb@umbc.edu http://www.csee.umbc.edu/~nilanb/teaching/421/. Principles of Operating Systems

612 views • 50 slides

Operating Systems CMPSC 473

625 views • 50 slides

Chapter 9: Virtual Memory

Chapter 9: Virtual Memory. Objectives. To describe the benefits of a virtual memory system To explain the concepts of demand paging, page-replacement algorithms, and allocation of page frames To discuss the principle of the working-set model. Background.

561 views • 49 slides

Operating Systems

Operating Systems. Page Replacement Algorithms. Virtual Memory Management. Background Demand Paging Demand Segmentation Paging Considerations Page Replacement Algorithms Virtual Memory Policies. Page Replacement Algorithms. Want lowest page-fault rate.

749 views • 34 slides

Virtual Memory

Virtual Memory. Goals for Today. Virtual memory Mechanism How does it work? Policy What to replace ? How much to fetch?. disk. page 0. page 1. page table. page 2. page 3. page 4. page N. Physical memory. Virtual memory. What is virtual memory?.

455 views • 31 slides

Virtual Memory

Virtual Memory. Why? The need of memory more than the available physical memory. Process 3. Physical Memory. Process 2. Process 1. Process 4. Memory Limits for Windows Releases http://msdn.microsoft.com/en-us/library/windows/desktop/aa366778(v=vs.85).aspx. Max. memory per a process.

418 views • 31 slides

Buffer and File organization

Buffer and File organization. Review. DBMSs store data on disk Disk characteristics: 2 orders of magnitude slower than MM Unit of read/write operations a block/page (multiple of sectors) Access time = seek time + rotation time + transfer time Sequential I/O much faster than random I/O

416 views • 30 slides

Virtual Memory

373 views • 30 slides

Module 10: Virtual Memory

483 views • 29 slides

9.4 Page Replacement

500 views • 28 slides

Chapter 9: Virtual Memory

Chapter 9: Virtual Memory. Virtual Memory. Can be implemented via: Demand paging Demand segmentation temp. Demand Paging. Bring a page into memory only when it is needed Page table used for tracking which pages are in memory Page fault if not in memory Get empty frame

392 views • 27 slides

CPS110: Page replacement

CPS110: Page replacement. Landon Cox. Replacement. Think of physical memory as a cache What happens on a cache miss? Page fault Must decide what to evict Goal: reduce number of misses. Review of replacement algorithms. Random Easy implementation, not great results

416 views • 25 slides

Allocation of Frames & Thrashing (Virtual Memory)

Allocation of Frames & Thrashing (Virtual Memory). LRU Algorithm. Reference string: 1, 2, 3, 4, 1, 2, 5, 1, 2, 3, 4, 5 Counter implementation: Every page entry has a counter; every time page is referenced through this entry, copy the clock into the counter.

1.13k views • 23 slides

Paging Algorithms

Paging Algorithms. Vivek Pai / Kai Li Princeton University. Virtual Memory Gedankenexperiment. Assume memory costs $20 per 256MB What does it cost to fill a 32-bit system? What does it cost to fill a 64-bit system? What about at $1 per 256MB?

468 views • 22 slides

Chapter 9: Virtual Memory

Chapter 9: Virtual Memory. Chapter 9: Virtual Memory. Background Demand Paging Copy-on-Write Page Replacement Allocation of Frames Thrashing Memory-Mapped Files Allocating Kernel Memory Other Considerations Operating-System Examples. Background.

389 views • 22 slides

Chapter 22. Beyond Physical Memory: Policies

Chapter 22. Beyond Physical Memory: Policies. Hyunjoon Kim (hjkim@theory.snu.ac.kr) School of Computer Science and Engineering Seoul National University. Introduction. When little memory is free,

695 views • 21 slides

Chapter 22. Beyond Physical Memory: Policies

Chapter 22. Beyond Physical Memory: Policies. Hyunjoon Kim (hjkim@theory.snu.ac.kr) School of Computer Science and Engineering Seoul National University. Introduction. When little memory is free,

215 views • 21 slides

Second-Chance Algorithm

296 views • 17 slides

Analog Devices FMCOMMS1-EBZ

255 views • 10 slides

Buffer Management Notes

101 views • 7 slides