On 06/28/2012 08:55 AM, Andrea Arcangeli wrote:
static inline int pte_file(pte_t pte)
{
- return pte_flags(pte)& _PAGE_FILE;
+ return (pte_flags(pte)& _PAGE_FILE) == _PAGE_FILE;
}
Wait, why is this change made? Surely _PAGE_FILE is just
one single bit and this change is not useful?
If there is a reason for this change, please document it.
@@ -405,7 +405,9 @@ static inline int pte_same(pte_t a, pte_t b)
static inline int pte_present(pte_t a)
{
- return pte_flags(a)& (_PAGE_PRESENT | _PAGE_PROTNONE);
+ /* _PAGE_NUMA includes _PAGE_PROTNONE */
+ return pte_flags(a)& (_PAGE_PRESENT | _PAGE_PROTNONE |
+ _PAGE_NUMA_PTE);
}
static inline int pte_hidden(pte_t pte)
@@ -415,7 +417,46 @@ static inline int pte_hidden(pte_t pte)
static inline int pmd_present(pmd_t pmd)
{
- return pmd_flags(pmd)& _PAGE_PRESENT;
+ return pmd_flags(pmd)& (_PAGE_PRESENT | _PAGE_PROTNONE |
+ _PAGE_NUMA_PMD);
+}
Somewhat subtle. Better documentation in patch 5 will
help explain this.
+#ifdef CONFIG_AUTONUMA
+static inline int pte_numa(pte_t pte)
+{
+ return (pte_flags(pte)&
+ (_PAGE_NUMA_PTE|_PAGE_PRESENT)) == _PAGE_NUMA_PTE;
+}
+
+static inline int pmd_numa(pmd_t pmd)
+{
+ return (pmd_flags(pmd)&
+ (_PAGE_NUMA_PMD|_PAGE_PRESENT)) == _PAGE_NUMA_PMD;
+}
+#endif
These could use a little explanation of how _PAGE_NUMA_* is
used and what the flags mean.
+static inline pte_t pte_mknotnuma(pte_t pte)
+{
+ pte = pte_clear_flags(pte, _PAGE_NUMA_PTE);
+ return pte_set_flags(pte, _PAGE_PRESENT|_PAGE_ACCESSED);
+}
+
+static inline pmd_t pmd_mknotnuma(pmd_t pmd)
+{
+ pmd = pmd_clear_flags(pmd, _PAGE_NUMA_PMD);
+ return pmd_set_flags(pmd, _PAGE_PRESENT|_PAGE_ACCESSED);
+}
+
+static inline pte_t pte_mknuma(pte_t pte)
+{
+ pte = pte_set_flags(pte, _PAGE_NUMA_PTE);
+ return pte_clear_flags(pte, _PAGE_PRESENT);
+}
+
+static inline pmd_t pmd_mknuma(pmd_t pmd)
+{
+ pmd = pmd_set_flags(pmd, _PAGE_NUMA_PMD);
+ return pmd_clear_flags(pmd, _PAGE_PRESENT);
}
These functions could use some explanation, too.
Why do the top ones set _PAGE_ACCESSED, while the bottom ones
leave _PAGE_ACCESSED alone?
I can guess the answer, but it should be documented so it is
also clear to people with less experience in the VM.
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