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Give an example that illustrat

[问答题]
Give an example that illustrates the problem with restarting the block move instruction (MVC) on the IBM 360/370 when the source and destination regions are overlapping.

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Assume that the page boundary is at 1024 and the move instruction is moving values from a source region of 800:1200 to a target region of 700:1100. Assume that a page fault occurs while accessing location 1024. By this time the locations of 800:923 have been overwritten
with the new values and therefore restarting the block move instruction would result in copying the new values in 800:923 to locations 700:823,
which is incorrect.
发表于 2018-03-23 21:57:10 回复(0)