作者assassin88 (...)
看板Grad-ProbAsk
标题Re: [理工] [OS]-memory和一些名词..
时间Wed Dec 23 23:52:11 2009
※ 引述《bernachom (Terry)》之铭言：
: 请教一下
: 这题是一个TLB的计算
: A virtual memory system often implements a TLB to speed up the
: virtual-to-physical address translation.
: A TLB has the following characteristics. Assume each TLB entry has a valid bit
: a dirty bit, a tag, and the page number. Determine the exact total number of
: bits to implement this TLB.
: -It is direct-mapped.
: -It has 16 entries.
: -The page size is 4K bytes.
: -The virtual address space is 4G bytes.
: -The physical memory is 1G bytes.
: 我计算是 20+18+1+1=40 40*16=640
: 和书上算的好像不太一样..我这样子算是哪里错了?
: 其它的就是一些名词了
: 查过之後还是不太了解，希望可以帮忙解答一下..
: 1.regular function call
: 2.ioctl system call
: 3.process migration
: 谢谢帮忙
page size : 4KB => 2^12B
va : 4GB = 2^32B => 32bits
pa : 1GB = 2^30B => 30bits
16 entries => 2^4 => index = 4bits
so, 32 - 12 - 4 = 16bits = tag
=>2^4*(1+1+16+18)=576bits
有错请指教。
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1F：推 bernachom:了解..我是看着恐龙画的图想说怎麽怪怪的..谢谢 12/24 00:05
2F：→ assassin88:差很多..我有时也会被搞混= = 12/24 00:45