f274a47134
First, pmap_clear_modify() is write protecting all mappings to the specified page, not just clearing the modified bit. Specifically, it sets PTE_RO on the PTE, which is wrong. Moreover, it is calling vm_page_dirty(), which is not the expected behavior for pmap_clear_modify(). Generally speaking, the machine-independent VM layer masks these mistakes. For example, setting PTE_RO will result in additional soft faults, but not a catastrophe. Second, pmap_clear_modify() may not clear the modified bits because it only iterates over the PV list when the page has the PV_TABLE_MOD flag set and elsewhere the pmap clears the PV_TABLE_MOD flag anytime a modified mapping is write protected or destroyed. However, the page may still have other mappings with the modified bit set. Eliminate a stale comment. |
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adm5120 | ||
alchemy | ||
atheros | ||
cavium | ||
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gxemul | ||
idt | ||
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malta | ||
mips | ||
nlm | ||
rmi | ||
rt305x | ||
sentry5 | ||
sibyte |