[英]How does a processor know that a page is not mapped in main memory but is in backing store?
In the X86 architecture how does a processor know that a page is not mapped in main memory but is in backing store, is their a flag in the page table entry that indicates that or is it only after the translation into physical address that the processor realizes the location of the Frame? 在X86体系结构中,处理器如何知道页面未映射到主内存中而是位于后备存储中,是它们在页表项中的标志,该标志指示是否仅在处理器转换为物理地址后才能实现框架的位置? In my understanding when the 'P' flag in the Page structure entry is set it indicates that a valid mapping for the logical address does not exist and a Page fault follows, in case when the mapping is present but the page is in backing store than also Page fault occurs and the page is swapped into memory and the page table entry modified.
根据我的理解,如果在页面结构条目中设置了“ P”标志,则表明该逻辑地址不存在有效的映射,并且在出现映射但页面位于后备存储的情况下出现了页面错误。还发生页面错误,页面被交换到内存中,并且页面表项被修改。
I think you are referring to a HARD page fault VS a SOFT page fault. 我认为您指的是HARD页面错误VS SOFT页面错误。 A hard page fault will be fired if:
如果出现以下情况,将引发硬页面错误:
A soft page fault will fire if the page is present but is else ware in memory (maybe on a different working set or leaving the working set) 如果存在页面,但其他页面仍在内存中(可能在其他工作集上或离开工作集),则会触发软页面错误
http://blogs.technet.com/b/askperf/archive/2008/06/10/the-basics-of-page-faults.aspx http://en.wikipedia.org/wiki/Page_fault (minor vs major) http://blogs.technet.com/b/askperf/archive/2008/06/10/the-basics-of-page-faults.aspx http://en.wikipedia.org/wiki/Page_fault (次要vs主要)
hope this help :) 希望这个帮助:)
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