Don't understand vm_page_prot
I'm reading about vm_area_struct in Mel Gorman's book on the Linux VM, and he says that the vm_page_prot field in structure vm_area_struct contains "protection flags that are set for each PTE in this VMA". These are the _PAGE_xxx flags in pgtable.h.
The problem I have is that these flags describe individual pages. For instance, _PAGE_DIRTY says that this particular page is dirty. So what does it mean if _PAGE_DIRTY is set in vm_page_prot? Does that mean that every page in this VMA is dirty? What if only some of the pages are dirty?
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Timur Tabi Staff Software Engineer [email protected] -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"[email protected]"> [email protected] </a>