作者steven9374 (steven)
看板Grad-ProbAsk
标题[理工] [计组]-90台大-average access time
时间Fri Jan 15 16:10:16 2010
Virtual memory is often implemented by demand-page.
Consider an operating system with on-demand paging
over a single-level page table,where the page table
of each process always resides in the memory.
Suspose that the TLB access time,the memory access time,
and the acerage page-fault service time are 20ns,100ns,25ms,
respectively.Let the hit ratio of TLB and the page fault
rate be 98% and 0.0001%,respectively.What is the effective
access time?
答案写=0.98*(20+100)+0.02*(20+100+100)*0.999999+
0.02*0.000001*(25+100+25000000)=122.5ns
後面实在看不太懂...
请求板上大大的教教小弟我
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