On Tue, Dec 04, 2018 at 10:17:48AM +0200, Mike Rapoport wrote:
On Mon, Dec 03, 2018 at 03:18:17PM -0500, jglisse@redhat.com wrote:
quoted
From: Jérôme Glisse <redacted>
[...]
quoted
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index cbeece8e47d4..3077d487be8b 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -25,10 +25,43 @@ struct mmu_notifier_mm {
spinlock_t lock;
};
+/*
+ * What event is triggering the invalidation:
Can you please make it kernel-doc comment?
Sorry should have done that in the first place, Andrew i will post a v2
with that and fixing my one stupid bug.
quoted
+ *
+ * MMU_NOTIFY_UNMAP
+ * either munmap() that unmap the range or a mremap() that move the range
+ *
+ * MMU_NOTIFY_CLEAR
+ * clear page table entry (many reasons for this like madvise() or replacing
+ * a page by another one, ...).
+ *
+ * MMU_NOTIFY_PROTECTION_VMA
+ * update is due to protection change for the range ie using the vma access
+ * permission (vm_page_prot) to update the whole range is enough no need to
+ * inspect changes to the CPU page table (mprotect() syscall)
+ *
+ * MMU_NOTIFY_PROTECTION_PAGE
+ * update is due to change in read/write flag for pages in the range so to
+ * mirror those changes the user must inspect the CPU page table (from the
+ * end callback).
+ *
+ *
+ * MMU_NOTIFY_SOFT_DIRTY
+ * soft dirty accounting (still same page and same access flags)
+ */
+enum mmu_notifier_event {
+ MMU_NOTIFY_UNMAP = 0,
+ MMU_NOTIFY_CLEAR,
+ MMU_NOTIFY_PROTECTION_VMA,
+ MMU_NOTIFY_PROTECTION_PAGE,
+ MMU_NOTIFY_SOFT_DIRTY,
+};