Soma: Created page with "==Video== Video from the lecture given on October 12, 2017 [http://homeostasis.scs.carleton.ca/~soma/os-2017f/lectures/comp3000-2017f-lec11-12Oct2017.mp4 is now available]...."

2017-10-12T22:19:16Z

Created page with "==Video== Video from the lecture given on October 12, 2017 [http://homeostasis.scs.carleton.ca/~soma/os-2017f/lectures/comp3000-2017f-lec11-12Oct2017.mp4 is now available]...."

New page

==Video==

Video from the lecture given on October 12, 2017 [http://homeostasis.scs.carleton.ca/~soma/os-2017f/lectures/comp3000-2017f-lec11-12Oct2017.mp4 is now available]. (I thought there was a recording fail during the lecture but seems that it worked fine. If there are any glitches let me know!)

==Notes==

===In-Class===

<pre>
Virtual memory
--------------

every process has a virtual address mapping
kernel maintains mapping of virtual->physical memory
- these are page tables

accessing page tables in main memory on every memory access
- crazy slow

cache of virtual->physical memory mappings

on every memory access
- check the cache for the mapping, use if there (fast)
- if not, check the page table (slow)

TLB is the cache of virtual->physical memory mappings
"translation lookaside buffer"

Table:
virt prefix -> phys prefix (top 20 bits on 32-bit architectures)
- "every" entry is checked in parallel on each access
</pre>

==Code==

Files from the lecture [http://homeostasis.scs.carleton.ca/~soma/os-2017f/code/lec11/ are available].

Operating Systems 2017F Lecture 11 - Revision history

Soma: Created page with "==Video== Video from the lecture given on October 12, 2017 [http://homeostasis.scs.carleton.ca/~soma/os-2017f/lectures/comp3000-2017f-lec11-12Oct2017.mp4 is now available]...."