作者zelkova (祥)
看板Grad-ProbAsk
標題[理工] [OS] File system
時間Mon Jan 31 02:13:04 2011
1. Which statements are false?
(A)index allocation has better performance than linked allocation.
(B)index allocation has poor performance than linked allocation.
Ans:(A)(B)are the same performance problem
請問index不是比較快嗎?
2. Storage can be dynamically allocated to the hosts attached to the same
storage-area network.
請問這句話錯在哪裡呢?
3. 這題題目很長.. 先提一下疑問@@.. 解答在求page table的entry用了 32+4 bits
從算式來看, 解答把offset(14bits)也存進page table惹...
不過entry裡面應該不用存offset吧? 這樣是不是 18+4 bits就OK了捏?
Consider a virtual memory system with the following properties:
38-bit virtual byte address. 16-KB pages, and 32-bit physical byte address.
What is the total size of the page table for each process on this machine,
assuming that the valid. Protection, dirty, and use bits take a total of 4
bits and the all the virtual pages are in use? (Assume that disk address are
not stored in the page table)
4.
http://www2.lib.nctu.edu.tw/n_exam/exam92/cis/cis136.pdf
12題答案是(A).. 請問怎麼解答的呢?
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◆ From: 220.135.91.184
※ 編輯: zelkova 來自: 220.135.91.184 (01/31 04:34)
1F：推 aoqq12:....空間分配跟執行速度應該沒什麼關係 02/01 14:18
2F：→ aoqq12:跟seek time比較有關係 02/01 14:18
3F：推 aoqq12:第三題 嗯它寫錯了沒錯 2^24(4+18)bit 02/01 14:27
4F：→ zelkova:謝謝一樓戴眼鏡的同學~ ...Q2跟Q4請大家幫幫忙@@ 02/02 00:28
5F：→ aerystyle:Q4 因為沒有互次存取所以會有race condition的問題 02/05 21:11
6F：→ aerystyle:因為主要為C.D的值在改變，所以只需討論他們的執行順序 02/05 21:13
7F：→ aerystyle:1.(80.80)C:先T1再T2，D:T2先assignT1再assign 02/05 21:15
8F：→ aerystyle:2.(120.80)C:T2先assignT1再assignD:T2先assignT1再assi 02/05 21:20
9F：→ aerystyle:gn，其他的就差不多的做法，有問題在站內信問我吧 02/05 21:21