Re: [PATCH] mm/vmalloc: track which page-table levels were modified

[Mike Rapoport <rppt@linux.ibm.com>]

On Fri, Jun 05, 2020 at 10:16:44AM +0200, Joerg Roedel wrote:
> On Thu, Jun 04, 2020 at 02:12:14PM -0700, Linus Torvalds wrote:
> > That said, the commentary about "why is p.._alloc_track() in such a
> > core header file, when it's only used by two special cases" is
> > probably still true regardless of the 5-level fixup header.. I assume
> > Mike didn't do those kinds of changes?
> 
> I'll try to move them to a separate header next week. The compile
> testing I set up for this patch-set will certainly be helpful for that
> :)

We already have include/asm-generic/pgalloc.h, so maybe something like
that patch below would fork. This is not even compile tested.

diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
index 73f7421413cb..7aa9c98aff47 100644
--- a/include/asm-generic/pgalloc.h
+++ b/include/asm-generic/pgalloc.h
@@ -102,6 +102,66 @@ static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
 	__free_page(pte_page);
 }
 
+static inline p4d_t *p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
+		unsigned long address)
+{
+	return (unlikely(pgd_none(*pgd)) && __p4d_alloc(mm, pgd, address)) ?
+		NULL : p4d_offset(pgd, address);
+}
+
+static inline pud_t *pud_alloc(struct mm_struct *mm, p4d_t *p4d,
+		unsigned long address)
+{
+	return (unlikely(p4d_none(*p4d)) && __pud_alloc(mm, p4d, address)) ?
+		NULL : pud_offset(p4d, address);
+}
+
+static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
+				     unsigned long address,
+				     pgtbl_mod_mask *mod_mask)
+
+{
+	if (unlikely(pgd_none(*pgd))) {
+		if (__p4d_alloc(mm, pgd, address))
+			return NULL;
+		*mod_mask |= PGTBL_PGD_MODIFIED;
+	}
+
+	return p4d_offset(pgd, address);
+}
+
+static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
+				     unsigned long address,
+				     pgtbl_mod_mask *mod_mask)
+{
+	if (unlikely(p4d_none(*p4d))) {
+		if (__pud_alloc(mm, p4d, address))
+			return NULL;
+		*mod_mask |= PGTBL_P4D_MODIFIED;
+	}
+
+	return pud_offset(p4d, address);
+}
+
+static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
+{
+	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
+		NULL: pmd_offset(pud, address);
+}
+
+static inline pmd_t *pmd_alloc_track(struct mm_struct *mm, pud_t *pud,
+				     unsigned long address,
+				     pgtbl_mod_mask *mod_mask)
+{
+	if (unlikely(pud_none(*pud))) {
+		if (__pmd_alloc(mm, pud, address))
+			return NULL;
+		*mod_mask |= PGTBL_PUD_MODIFIED;
+	}
+
+	return pmd_offset(pud, address);
+}
+
 #endif /* CONFIG_MMU */
 
 #endif /* __ASM_GENERIC_PGALLOC_H */
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 3f1649a8cf55..36ac65f4744f 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -14,7 +14,6 @@
 #include <linux/mmu_notifier.h>
 #include <linux/swap.h>
 #include <linux/hugetlb_inline.h>
-#include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
 #include <asm/cacheflush.h>
 
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 86adc71a972f..29a3d7c492f0 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2068,69 +2068,6 @@ static inline void mm_dec_nr_ptes(struct mm_struct *mm) {}
 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd);
 int __pte_alloc_kernel(pmd_t *pmd);
 
-#if defined(CONFIG_MMU)
-
-static inline p4d_t *p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
-		unsigned long address)
-{
-	return (unlikely(pgd_none(*pgd)) && __p4d_alloc(mm, pgd, address)) ?
-		NULL : p4d_offset(pgd, address);
-}
-
-static inline pud_t *pud_alloc(struct mm_struct *mm, p4d_t *p4d,
-		unsigned long address)
-{
-	return (unlikely(p4d_none(*p4d)) && __pud_alloc(mm, p4d, address)) ?
-		NULL : pud_offset(p4d, address);
-}
-
-static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
-				     unsigned long address,
-				     pgtbl_mod_mask *mod_mask)
-
-{
-	if (unlikely(pgd_none(*pgd))) {
-		if (__p4d_alloc(mm, pgd, address))
-			return NULL;
-		*mod_mask |= PGTBL_PGD_MODIFIED;
-	}
-
-	return p4d_offset(pgd, address);
-}
-
-static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
-				     unsigned long address,
-				     pgtbl_mod_mask *mod_mask)
-{
-	if (unlikely(p4d_none(*p4d))) {
-		if (__pud_alloc(mm, p4d, address))
-			return NULL;
-		*mod_mask |= PGTBL_P4D_MODIFIED;
-	}
-
-	return pud_offset(p4d, address);
-}
-
-static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
-{
-	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
-		NULL: pmd_offset(pud, address);
-}
-
-static inline pmd_t *pmd_alloc_track(struct mm_struct *mm, pud_t *pud,
-				     unsigned long address,
-				     pgtbl_mod_mask *mod_mask)
-{
-	if (unlikely(pud_none(*pud))) {
-		if (__pmd_alloc(mm, pud, address))
-			return NULL;
-		*mod_mask |= PGTBL_PUD_MODIFIED;
-	}
-
-	return pmd_offset(pud, address);
-}
-#endif /* CONFIG_MMU */
-
 #if USE_SPLIT_PTE_PTLOCKS
 #if ALLOC_SPLIT_PTLOCKS
 void __init ptlock_cache_init(void);
diff --git a/lib/ioremap.c b/lib/ioremap.c
index ad485f08173b..357e5909a364 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -13,6 +13,7 @@
 #include <linux/export.h>
 #include <asm/cacheflush.h>
 #include <asm/pgtable.h>
+#include <asm/pgalloc.h>
 
 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
 static int __read_mostly ioremap_p4d_capable;
diff --git a/mm/mremap.c b/mm/mremap.c
index 7d69e3fe51aa..4a6c4db8747b 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -27,6 +27,7 @@
 
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
 
 #include "internal.h"
 
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 3091c2ca60df..84a6d08416a2 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -39,6 +39,7 @@
 #include <linux/uaccess.h>
 #include <asm/tlbflush.h>
 #include <asm/shmparam.h>
+#include <asm/pgalloc.h>
 
 #include "internal.h"
 

> 
> 	Joerg
> 

-- 
Sincerely yours,
Mike.