[PATCH -next v3 1/2] mm/debug_vm_pgtable: Move {pmd/pud}_huge_tests out of CONFIG_TRANSPARENT_HUGEPAGE

[PATCH -next v3 1/2] mm/debug_vm_pgtable: Move {pmd/pud}_huge_tests out of CONFIG_TRANSPARENT_HUGEPAGE

[Liu Shixin]

From: Shixin Liu <liushixin2@huawei.com>

The functions {pmd/pud}_set_huge and {pmd/pud}_clear_huge are not dependent
on THP. Hence move {pmd/pud}_huge_tests out of CONFIG_TRANSPARENT_HUGEPAGE.

Signed-off-by: Shixin Liu <liushixin2@huawei.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
v2->v3:
Modified the commit message and fix a checkpatch warning.
v1->v2:
Modified the commit message.

 mm/debug_vm_pgtable.c | 91 +++++++++++++++++++------------------------
 1 file changed, 39 insertions(+), 52 deletions(-)

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 05efe98a9ac2..d3cf178621d9 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -242,29 +242,6 @@ static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
 	WARN_ON(!pmd_leaf(pmd));
 }
 
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
-{
-	pmd_t pmd;
-
-	if (!arch_vmap_pmd_supported(prot))
-		return;
-
-	pr_debug("Validating PMD huge\n");
-	/*
-	 * X86 defined pmd_set_huge() verifies that the given
-	 * PMD is not a populated non-leaf entry.
-	 */
-	WRITE_ONCE(*pmdp, __pmd(0));
-	WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot));
-	WARN_ON(!pmd_clear_huge(pmdp));
-	pmd = READ_ONCE(*pmdp);
-	WARN_ON(!pmd_none(pmd));
-}
-#else /* CONFIG_HAVE_ARCH_HUGE_VMAP */
-static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) { }
-#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
-
 static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
 {
 	pmd_t pmd = pfn_pmd(pfn, prot);
@@ -379,30 +356,6 @@ static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
 	pud = pud_mkhuge(pud);
 	WARN_ON(!pud_leaf(pud));
 }
-
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
-{
-	pud_t pud;
-
-	if (!arch_vmap_pud_supported(prot))
-		return;
-
-	pr_debug("Validating PUD huge\n");
-	/*
-	 * X86 defined pud_set_huge() verifies that the given
-	 * PUD is not a populated non-leaf entry.
-	 */
-	WRITE_ONCE(*pudp, __pud(0));
-	WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot));
-	WARN_ON(!pud_clear_huge(pudp));
-	pud = READ_ONCE(*pudp);
-	WARN_ON(!pud_none(pud));
-}
-#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
-static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { }
-#endif /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
-
 #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
 static void __init pud_advanced_tests(struct mm_struct *mm,
@@ -412,9 +365,6 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
 {
 }
 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
-static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
-{
-}
 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 static void __init pmd_basic_tests(unsigned long pfn, int idx) { }
@@ -433,14 +383,51 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
 }
 static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) { }
 static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
 static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
 {
+	pmd_t pmd;
+
+	if (!arch_vmap_pmd_supported(prot))
+		return;
+
+	pr_debug("Validating PMD huge\n");
+	/*
+	 * X86 defined pmd_set_huge() verifies that the given
+	 * PMD is not a populated non-leaf entry.
+	 */
+	WRITE_ONCE(*pmdp, __pmd(0));
+	WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot));
+	WARN_ON(!pmd_clear_huge(pmdp));
+	pmd = READ_ONCE(*pmdp);
+	WARN_ON(!pmd_none(pmd));
 }
+
 static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
 {
+	pud_t pud;
+
+	if (!arch_vmap_pud_supported(prot))
+		return;
+
+	pr_debug("Validating PUD huge\n");
+	/*
+	 * X86 defined pud_set_huge() verifies that the given
+	 * PUD is not a populated non-leaf entry.
+	 */
+	WRITE_ONCE(*pudp, __pud(0));
+	WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot));
+	WARN_ON(!pud_clear_huge(pudp));
+	pud = READ_ONCE(*pudp);
+	WARN_ON(!pud_none(pud));
 }
-static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { }
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
+static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) { }
+static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
 
 static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
 {
-- 
2.25.1

[PATCH -next v3 2/2] mm/debug_vm_pgtable: Remove redundant pfn_{pmd/pte}() and fix one comment mistake

[Liu Shixin]

From: Shixin Liu <liushixin2@huawei.com>

Remove redundant pfn_{pmd/pte}() in {pmd/pte}_advanced_tests()
and adjust pfn_pud() in pud_advanced_tests() to make it similar with
other two functions.
In addition, the branch condition should be CONFIG_TRANSPARENT_HUGEPAGE
instead of CONFIG_ARCH_HAS_PTE_DEVMAP.

Signed-off-by: Shixin Liu <liushixin2@huawei.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
v2->v3:
Modified the commit message.
v1->v2:
Remove redundant pfn_pte() and fold two patch to one.

 mm/debug_vm_pgtable.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index d3cf178621d9..e2f35db8ba69 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -91,7 +91,7 @@ static void __init pte_advanced_tests(struct mm_struct *mm,
 				      unsigned long pfn, unsigned long vaddr,
 				      pgprot_t prot)
 {
-	pte_t pte = pfn_pte(pfn, prot);
+	pte_t pte;
 
 	/*
 	 * Architectures optimize set_pte_at by avoiding TLB flush.
@@ -185,7 +185,7 @@ static void __init pmd_advanced_tests(struct mm_struct *mm,
 				      unsigned long pfn, unsigned long vaddr,
 				      pgprot_t prot, pgtable_t pgtable)
 {
-	pmd_t pmd = pfn_pmd(pfn, prot);
+	pmd_t pmd;
 
 	if (!has_transparent_hugepage())
 		return;
@@ -300,7 +300,7 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
 				      unsigned long pfn, unsigned long vaddr,
 				      pgprot_t prot)
 {
-	pud_t pud = pfn_pud(pfn, prot);
+	pud_t pud;
 
 	if (!has_transparent_hugepage())
 		return;
@@ -309,6 +309,7 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
 	/* Align the address wrt HPAGE_PUD_SIZE */
 	vaddr = (vaddr & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE;
 
+	pud = pfn_pud(pfn, prot);
 	set_pud_at(mm, vaddr, pudp, pud);
 	pudp_set_wrprotect(mm, vaddr, pudp);
 	pud = READ_ONCE(*pudp);
@@ -742,12 +743,12 @@ static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
 	WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
 	WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
 }
-#else  /* !CONFIG_ARCH_HAS_PTE_DEVMAP */
+#else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
 static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) { }
 static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
 {
 }
-#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot)
 {
-- 
2.25.1

Re: [PATCH -next v3 1/2] mm/debug_vm_pgtable: Move {pmd/pud}_huge_tests out of CONFIG_TRANSPARENT_HUGEPAGE

[Andrew Morton]

On Mon, 19 Apr 2021 15:18:19 +0800 Liu Shixin <liushixin2@huawei.com> wrote:

> The functions {pmd/pud}_set_huge and {pmd/pud}_clear_huge are not dependent
> on THP. Hence move {pmd/pud}_huge_tests out of CONFIG_TRANSPARENT_HUGEPAGE.

What is the actual effect of this?  Better test coverage?  Smaller
kernel?  Larger kernel?

(I'm too lazy to figure this out and it should have been in the
changelog anyway ;))

Re: [PATCH -next v3 1/2] mm/debug_vm_pgtable: Move {pmd/pud}_huge_tests out of CONFIG_TRANSPARENT_HUGEPAGE

[Liu Shixin]

On 2021/5/10 12:26, Andrew Morton wrote:
> On Mon, 19 Apr 2021 15:18:19 +0800 Liu Shixin <liushixin2@huawei.com> wrote:
>
>> The functions {pmd/pud}_set_huge and {pmd/pud}_clear_huge are not dependent
>> on THP. Hence move {pmd/pud}_huge_tests out of CONFIG_TRANSPARENT_HUGEPAGE.
> What is the actual effect of this?  Better test coverage?  Smaller
> kernel?  Larger kernel?
>
> (I'm too lazy to figure this out and it should have been in the
> changelog anyway ;))
> .
>
Better test coverage I think.

And I want to add HUGE_VMAP support for riscv, which doesn't have THP support right now.