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Recall the initial rules for MLFQ are: If Priority(A) > Priority(B) then A runs If Priority(A) == Priority(B) then A&B run in RR Jobs start at top priority If a job uses its whole time slice then it is demoted These initial rules had several problems and needed to be changed.  What is one problem with these initial rules and the modification that was made to correct for this problem?

The portion of trap.h and syscall.h files for xv6 are shown in the table below.

hex offset   0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1fdec offset   0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 310×44 ( 68): 06 09 18 1a 05 01 14 19 1d 0f 0f 17 03 04 14 13 08 03 0d 0e 06 1c 0d 01 14 1a 03 0a 11 0f 1e 020×45 ( 69): 01 00 14 18 12 17 10 12 19 01 12 19 11 02 0e 1e 1d 0a 0d 19 18 05 0b 14 0e 13 14 1b 10 19 15 1e0x46 ( 70): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000×47 ( 71): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000×48 ( 72): 02 1b 0a 09 14 17 1a 15 10 18 15 17 11 19 08 0d 04 19 1a 1e 19 15 02 07 1a 11 1c 11 14 14 03 0d0x49 ( 73): 10 06 0b 1d 18 07 1c 03 03 17 15 02 12 19 00 04 04 0c 0a 18 1b 18 11 09 11 1b 19 14 05 12 0b 0d0x4a ( 74): 7f 7f 7f fc 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 84 7f 7f 7f 7f f8 7f 7f0x4b ( 75): 10 07 1c 0e 17 19 15 09 17 1d 0f 00 1b 0d 11 11 0e 00 18 01 11 06 17 02 04 1a 11 16 18 19 1e 170x4c ( 76): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000x4d ( 77): 11 00 01 14 13 0d 1b 17 1b 1c 0c 00 1d 1c 15 10 01 0b 17 14 0b 0c 13 16 11 09 1e 17 05 17 1a 130x4e ( 78): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000x4f ( 79): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000×50 ( 80): 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f e6 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f0x51 ( 81): 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f d3 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f df a2 ac 7f 7f 7f 7f 7f0x52 ( 82): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000×53 ( 83): 07 1c 02 0c 17 18 02 14 14 05 0d 00 1d 00 15 19 19 0b 09 0c 0e 13 15 0e 1b 0e 0c 0d 08 0e 02 170×54 ( 84): be a7 e4 9d 7f 7f 92 7f d7 99 a0 e5 a9 9c a1 82 ca ba f2 7f b8 97 bd c1 e8 e2 d0 d1 ab d9 c3 8b0x55 ( 85): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000×56 ( 86): 05 08 08 1a 00 10 03 03 08 19 0e 11 10 13 00 15 0b 10 0d 0f 01 11 07 17 1b 00 08 1b 0a 0b 18 100×57 ( 87): 7f 86 7f 87 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f ed 7f 7f 7f 7f 7f 7f 7f 7f d6 7f 7f 7f 7f 89 7f0x58 ( 88): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000×59 ( 89): 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f e1 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f cb 7f 7f 7f 7f0x5a ( 90): 08 0e 03 07 02 08 0f 10 07 1c 01 0a 0e 15 15 0e 15 02 16 1b 1e 10 11 16 16 1a 06 05 1e 18 1c 010x5b ( 91): 05 05 16 15 12 10 13 17 14 04 07 1a 0b 14 16 07 0c 0c 0c 07 0d 0f 1c 19 1c 12 18 09 07 1d 1b 190x5c ( 92): 1b 1b 1d 04 0b 0b 03 06 08 0e 16 1a 1a 0c 0a 0f 1a 06 13 0d 03 09 0e 0a 19 15 1b 02 19 18 04 1e0x5d ( 93): 13 00 09 12 0e 06 05 1b 05 18 1a 00 16 11 11 13 14 12 1e 0f 1e 0a 0c 01 14 1e 09 16 17 01 00 1b0x5e ( 94): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000x5f ( 95): 0c 11 0a 09 07 1b 1c 02 07 10 12 02 09 1a 13 02 15 04 19 08 18 17 06 19 10 13 09 1c 0f 1d 02 0d0x60 ( 96): 0a 16 05 12 1d 1d 04 05 04 0d 0a 05 0c 11 18 06 10 07 10 0b 15 03 14 08 18 04 02 08 0c 16 12 0d0x61 ( 97): 13 01 01 16 11 0c 0e 10 02 0f 00 06 10 19 0a 0d 0f 17 14 14 04 1c 15 19 15 07 03 10 1b 0d 1b 1d0x62 ( 98): 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f bf 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f0x63 ( 99): 16 00 16 0d 05 0f 0c 10 0c 15 03 06 01 1e 17 0b 08 1e 09 0d 18 1b 12 19 05 00 03 0b 06 0d 0e 1a0x64 (100): 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f fa 7f 7f 7f 7f 7f 7f0x65 (101): 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 8c 7f 7f ef 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f0x66 (102): 02 05 07 19 06 1a 16 0e 16 01 1e 14 17 05 11 0d 04 1c 10 12 19 07 04 17 15 12 18 08 1e 05 17 170×67 (103): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000×68 (104): 7f 7f 7f 7f 7f 7f 7f 7f da 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f ee 7f 7f 7f 7f0x69 (105): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000x6a (106): 14 13 0e 17 0c 02 04 18 0e 14 01 18 12 17 1a 14 0d 14 16 0c 03 12 1d 07 08 16 06 02 0b 0d 1a 040x6b (107): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000x6c (108): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000x6d (109): 07 14 05 11 0a 07 0a 0f 08 0b 0d 0a 19 08 0d 0d 01 18 04 13 1b 01 09 0e 0e 1e 1a 03 0f 0a 01 1d0x6e (110): 12 02 19 1d 0f 1c 0e 1b 02 16 01 01 1d 02 0a 1d 05 08 01 1e 00 1d 16 0a 1b 19 1a 1a 1c 06 13 0e0x6f (111): 19 0a 00 02 0a 08 08 0d 07 01 14 18 04 02 16 0c 0b 1c 1b 04 05 0d 11 04 00 02 09 1b 01 15 04 0d0x70 (112): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000×71 (113): 14 17 05 08 14 18 0c 14 1b 0b 18 13 0c 13 06 1e 10 12 0c 04 1c 05 11 1d 05 10 05 1a 15 14 13 030×72 (114): 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 93 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f 7f0x73 (115): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000×74 (116): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000×75 (117): 1c 0d 19 0e 03 1c 1d 18 0c 10 18 1a 1a 08 0b 08 15 04 06 1a 1d 14 0b 17 00 1b 1b 1e 09 17 10 060×76 (118): 18 06 19 09 01 11 11 1d 08 0f 10 1c 10 1e 0f 05 0e 0e 04 13 0a 11 1c 11 0f 0e 06 17 12 02 06 0c0x77 (119): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000×78 (120): 1c 15 15 1c 11 06 18 09 07 00 17 0b 05 18 17 08 01 01 02 14 00 13 10 19 05 11 01 13 05 06 1e 190×79 (121): 19 07 04 19 07 14 14 06 01 14 19 02 15 0d 14 0f 14 01 06 04 13 0c 0a 15 13 03 12 1e 07 13 11 020x7a (122): 04 00 06 01 1a 13 03 1d 00 03 02 0d 1a 11 0f 14 0c 16 04 18 05 0b 03 17 1a 09 10 17 13 14 00 1c0x7b (123): 12 17 1e 06 1c 1d 02 0a 1a 1c 02 02 11 06 07 1a 0d 1c 1a 1a 09 12 0b 02 16 09 16 08 03 1a 1b 170x7c (124): 13 1a 09 1d 1a 17 10 08 0c 0a 04 0f 13 13 04 04 00 14 15 1b 10 14 05 11 03 1a 05 18 14 04 1e 0b0x7d (125): 12 1c 06 0e 0b 12 0d 0f 04 19 17 07 09 1c 07 10 04 10 07 0b 0b 1a 09 04 09 1e 1e 06 05 1d 05 010x7e (126): 16 0a 03 1a 1d 06 0f 0c 16 0f 0a 19 07 04 00 02 0c 1d 0c 1e 1c 19 1d 15 0c 0b 18 03 17 0f 15 1c0x7f (127): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

CS 537: Introduction to Operating Systems Fall 2024: Midterm Exam #1   This exam is closed book, but you may use 1 sheet of notes.   No calculators may be used.   You have 1 hour and 30 minutes to complete this exam. Unless stated (or implied) otherwise, you should make the following assumptions: The OS manages a single uniprocessor (single core) All memory is byte addressable Page table and page directory entries require 4 bytes Data is allocated with optimal alignment, starting at the beginning of a page Assume leading zeros can be removed from numbers (e.g., 0x06 == 0x6). Hex numbers are represented with a proceeding “0x” The following might help you with some calculations: 0x100 = 28 = 256 210 = 1024 212 = 4096 210 bytes = 1KB 220 bytes = 1MB   This exam has 60 questions.  Each question has the same number of points.   Good luck!

Now consider a function where we print the array contents in column order   void print_col_array(int *arr, int cols, int rows){    for(size_t i=0; i

When prog is executed how many times will the number 3 be printed?

Virtual Addressing using Segmentation

If the TLB size was increased to 8 entries, the TLB hit rate for the first function print_array would be:

Write the following phrases with possessive adjectives*. Follow the model. los cuadernos / yo        mis cuadernos *If you need accented letters or other special characters, you can use the button at the top of the browser that looks like a piece of paper with and “A” on it. A box will pop down with the characters you need (and a lot you don’t). Remember, accents in Spanish go this direction: á é í ó ú los lápices / Guillermo  [a] (his pencils) los padres / los estudiantes  [b] (their parents) los hijos / señor Ballesteros  [c] (his children) la computadora portátil / tú  [d] (your laptop) las familias / nosotros  [e] (our families)  

In C an array is stored in row-major format. For example, an integer array of shape 4×4 with data like the one is shown in Figure 2 in memory as shown in Figure 3. Assume there is a tiny address space where each page is of 8 bytes and there are 16 such pages. We have a 4×4 array and the element a[0] is located at virtual address 20. (Virtual Page Number=02, offset = 04). Assume size of integer is 4 bytes   Consider the following function:   void print_array(int *arr, int cols, int rows){   for (size_t i=0; i