Hi,
I've tried to trim down the recipients list, but it's still quite long, so
sorry for the spam.
Many architectures have similar, if not identical implementation of
pte_alloc_one_kernel(), pte_alloc_one(), pte_free_kernel() and pte_free().
A while ago Anshuman suggested to introduce a common definition of
GFP_PGTABLE and during the discussion it was suggested to rather
consolidate the allocators.
These patches introduce generic version of PTE allocation and free and
enable their use on several architectures.
The conversion introduces some changes for some of the architectures.
Here's the executive summary and the details are described at each patch.
* Most architectures do not set __GFP_ACCOUNT for the user page tables.
Switch to the generic functions is "spreading that goodness to all other
architectures"
* arm, arm64 and unicore32 used to check if the pte is not NULL before
freeing its memory in pte_free_kernel(). It's dropped during the
conversion as it seems superfluous.
* x86 used to BUG_ON() is pte was not page aligned duirng
pte_free_kernel(), the generic version simply frees the memory without any
checks.
This set only performs the straightforward conversion, the architectures
with different logic in pte_alloc_one() and pte_alloc_one_kernel() are not
touched, as well as architectures that have custom page table allocators.
[1] https://lore.kernel.org/lkml/[email protected]
asm-generic, x86: introduce generic pte_{alloc,free}_one[_kernel]
Mike Rapoport (15):
asm-generic, x86: introduce generic pte_{alloc,free}_one[_kernel]
alpha: switch to generic version of pte allocation
arm: switch to generic version of pte allocation
arm64: switch to generic version of pte allocation
csky: switch to generic version of pte allocation
hexagon: switch to generic version of pte allocation
m68k: sun3: switch to generic version of pte allocation
mips: switch to generic version of pte allocation
nds32: switch to generic version of pte allocation
nios2: switch to generic version of pte allocation
parisc: switch to generic version of pte allocation
powerpc/nohash/64: switch to generic version of pte allocation
riscv: switch to generic version of pte allocation
um: switch to generic version of pte allocation
unicore32: switch to generic version of pte allocation
arch/alpha/include/asm/pgalloc.h | 40 +---------
arch/arm/include/asm/pgalloc.h | 41 ++++------
arch/arm/mm/mmu.c | 2 +-
arch/arm64/include/asm/pgalloc.h | 43 +----------
arch/arm64/mm/mmu.c | 2 +-
arch/arm64/mm/pgd.c | 4 +-
arch/csky/include/asm/pgalloc.h | 30 +-------
arch/hexagon/include/asm/pgalloc.h | 34 +--------
arch/m68k/include/asm/sun3_pgalloc.h | 41 +---------
arch/mips/include/asm/pgalloc.h | 33 +--------
arch/nds32/include/asm/pgalloc.h | 31 +-------
arch/nios2/include/asm/pgalloc.h | 37 +--------
arch/parisc/include/asm/pgalloc.h | 33 +--------
arch/powerpc/include/asm/nohash/64/pgalloc.h | 35 +--------
arch/riscv/include/asm/pgalloc.h | 29 +-------
arch/um/include/asm/pgalloc.h | 16 +---
arch/um/kernel/mem.c | 22 ------
arch/unicore32/include/asm/pgalloc.h | 36 ++-------
arch/x86/include/asm/pgalloc.h | 19 +----
arch/x86/mm/pgtable.c | 33 +++------
include/asm-generic/pgalloc.h | 107 ++++++++++++++++++++++++++-
virt/kvm/arm/mmu.c | 2 +-
22 files changed, 171 insertions(+), 499 deletions(-)
--
2.7.4
um allocates PTE pages with __get_free_page() and uses
GFP_KERNEL | __GFP_ZERO for the allocations.
Switch it to the generic version that does exactly the same thing for the
kernel page tables and adds __GFP_ACCOUNT for the user PTEs.
The pte_free() and pte_free_kernel() versions are identical to the generic
ones and can be simply dropped.
Signed-off-by: Mike Rapoport <[email protected]>
---
arch/um/include/asm/pgalloc.h | 16 ++--------------
arch/um/kernel/mem.c | 22 ----------------------
2 files changed, 2 insertions(+), 36 deletions(-)
diff --git a/arch/um/include/asm/pgalloc.h b/arch/um/include/asm/pgalloc.h
index 99eb568..d7b282e 100644
--- a/arch/um/include/asm/pgalloc.h
+++ b/arch/um/include/asm/pgalloc.h
@@ -10,6 +10,8 @@
#include <linux/mm.h>
+#include <asm-generic/pgalloc.h> /* for pte_{alloc,free}_one */
+
#define pmd_populate_kernel(mm, pmd, pte) \
set_pmd(pmd, __pmd(_PAGE_TABLE + (unsigned long) __pa(pte)))
@@ -25,20 +27,6 @@
extern pgd_t *pgd_alloc(struct mm_struct *);
extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
-extern pte_t *pte_alloc_one_kernel(struct mm_struct *);
-extern pgtable_t pte_alloc_one(struct mm_struct *);
-
-static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
-{
- free_page((unsigned long) pte);
-}
-
-static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
-{
- pgtable_page_dtor(pte);
- __free_page(pte);
-}
-
#define __pte_free_tlb(tlb,pte, address) \
do { \
pgtable_page_dtor(pte); \
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 99aa11b..2280374 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -215,28 +215,6 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd)
free_page((unsigned long) pgd);
}
-pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
-{
- pte_t *pte;
-
- pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
- return pte;
-}
-
-pgtable_t pte_alloc_one(struct mm_struct *mm)
-{
- struct page *pte;
-
- pte = alloc_page(GFP_KERNEL|__GFP_ZERO);
- if (!pte)
- return NULL;
- if (!pgtable_page_ctor(pte)) {
- __free_page(pte);
- return NULL;
- }
- return pte;
-}
-
#ifdef CONFIG_3_LEVEL_PGTABLES
pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
{
--
2.7.4
Most architectures have identical or very similar implementation of
pte_alloc_one_kernel(), pte_alloc_one(), pte_free_kernel() and pte_free().
Add a generic implementation that can be reused across architectures and
enable its use on x86.
The generic implementation uses
GFP_KERNEL | __GFP_ZERO
for the kernel page tables and
GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT
for the user page tables.
The "base" functions for PTE allocation, namely __pte_alloc_one_kernel()
and __pte_alloc_one() are intended for the architectures that require
additional actions after actual memory allocation or must use non-default
GFP flags.
x86 is switched to use generic pte_alloc_one_kernel(), pte_free_kernel() and
pte_free().
x86 still implements pte_alloc_one() to allow run-time control of GFP flags
required for "userpte" command line option.
Signed-off-by: Mike Rapoport <[email protected]>
---
arch/x86/include/asm/pgalloc.h | 19 ++------
arch/x86/mm/pgtable.c | 33 ++++---------
include/asm-generic/pgalloc.h | 107 +++++++++++++++++++++++++++++++++++++++--
3 files changed, 115 insertions(+), 44 deletions(-)
diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
index a281e61..29aa785 100644
--- a/arch/x86/include/asm/pgalloc.h
+++ b/arch/x86/include/asm/pgalloc.h
@@ -6,6 +6,9 @@
#include <linux/mm.h> /* for struct page */
#include <linux/pagemap.h>
+#define __HAVE_ARCH_PTE_ALLOC_ONE
+#include <asm-generic/pgalloc.h> /* for pte_{alloc,free}_one */
+
static inline int __paravirt_pgd_alloc(struct mm_struct *mm) { return 0; }
#ifdef CONFIG_PARAVIRT_XXL
@@ -47,24 +50,8 @@ extern gfp_t __userpte_alloc_gfp;
extern pgd_t *pgd_alloc(struct mm_struct *);
extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
-extern pte_t *pte_alloc_one_kernel(struct mm_struct *);
extern pgtable_t pte_alloc_one(struct mm_struct *);
-/* Should really implement gc for free page table pages. This could be
- done with a reference count in struct page. */
-
-static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
-{
- BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
- free_page((unsigned long)pte);
-}
-
-static inline void pte_free(struct mm_struct *mm, struct page *pte)
-{
- pgtable_page_dtor(pte);
- __free_page(pte);
-}
-
extern void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte);
static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 7bd0170..aaca89b 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -13,33 +13,17 @@ phys_addr_t physical_mask __ro_after_init = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
EXPORT_SYMBOL(physical_mask);
#endif
-#define PGALLOC_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
-
#ifdef CONFIG_HIGHPTE
-#define PGALLOC_USER_GFP __GFP_HIGHMEM
+#define PGTABLE_HIGHMEM __GFP_HIGHMEM
#else
-#define PGALLOC_USER_GFP 0
+#define PGTABLE_HIGHMEM 0
#endif
-gfp_t __userpte_alloc_gfp = PGALLOC_GFP | PGALLOC_USER_GFP;
-
-pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
-{
- return (pte_t *)__get_free_page(PGALLOC_GFP & ~__GFP_ACCOUNT);
-}
+gfp_t __userpte_alloc_gfp = GFP_PGTABLE_USER | PGTABLE_HIGHMEM;
pgtable_t pte_alloc_one(struct mm_struct *mm)
{
- struct page *pte;
-
- pte = alloc_pages(__userpte_alloc_gfp, 0);
- if (!pte)
- return NULL;
- if (!pgtable_page_ctor(pte)) {
- __free_page(pte);
- return NULL;
- }
- return pte;
+ return __pte_alloc_one(mm, __userpte_alloc_gfp);
}
static int __init setup_userpte(char *arg)
@@ -235,7 +219,7 @@ static int preallocate_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
{
int i;
bool failed = false;
- gfp_t gfp = PGALLOC_GFP;
+ gfp_t gfp = GFP_PGTABLE_USER;
if (mm == &init_mm)
gfp &= ~__GFP_ACCOUNT;
@@ -401,14 +385,14 @@ static inline pgd_t *_pgd_alloc(void)
* We allocate one page for pgd.
*/
if (!SHARED_KERNEL_PMD)
- return (pgd_t *)__get_free_pages(PGALLOC_GFP,
+ return (pgd_t *)__get_free_pages(GFP_PGTABLE_USER,
PGD_ALLOCATION_ORDER);
/*
* Now PAE kernel is not running as a Xen domain. We can allocate
* a 32-byte slab for pgd to save memory space.
*/
- return kmem_cache_alloc(pgd_cache, PGALLOC_GFP);
+ return kmem_cache_alloc(pgd_cache, GFP_PGTABLE_USER);
}
static inline void _pgd_free(pgd_t *pgd)
@@ -422,7 +406,8 @@ static inline void _pgd_free(pgd_t *pgd)
static inline pgd_t *_pgd_alloc(void)
{
- return (pgd_t *)__get_free_pages(PGALLOC_GFP, PGD_ALLOCATION_ORDER);
+ return (pgd_t *)__get_free_pages(GFP_PGTABLE_USER,
+ PGD_ALLOCATION_ORDER);
}
static inline void _pgd_free(pgd_t *pgd)
diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
index 948714c..efecfb3 100644
--- a/include/asm-generic/pgalloc.h
+++ b/include/asm-generic/pgalloc.h
@@ -1,13 +1,112 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_GENERIC_PGALLOC_H
#define __ASM_GENERIC_PGALLOC_H
-/*
- * an empty file is enough for a nommu architecture
- */
+
#ifdef CONFIG_MMU
-#error need to implement an architecture specific asm/pgalloc.h
+
+#define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO)
+#define GFP_PGTABLE_USER (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT)
+
+/**
+ * __pte_alloc_one_kernel - allocate a page for PTE-level kernel page table
+ * @mm: the mm_struct of the current context
+ *
+ * This function is intended for architectures that need
+ * anything beyond simple page allocation.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+static inline pte_t *__pte_alloc_one_kernel(struct mm_struct *mm)
+{
+ return (pte_t *)__get_free_page(GFP_PGTABLE_KERNEL);
+}
+
+#ifndef __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
+/**
+ * pte_alloc_one_kernel - allocate a page for PTE-level kernel page table
+ * @mm: the mm_struct of the current context
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
+{
+ return __pte_alloc_one_kernel(mm);
+}
+#endif
+
+/**
+ * pte_free_kernel - free PTE-level kernel page table page
+ * @mm: the mm_struct of the current context
+ * @pte: pointer to the memory containing the page table
+ */
+static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
+{
+ free_page((unsigned long)pte);
+}
+
+/**
+ * __pte_alloc_one - allocate a page for PTE-level user page table
+ * @mm: the mm_struct of the current context
+ * @gfp: GFP flags to use for the allocation
+ *
+ * Allocates a page and runs the pgtable_page_ctor().
+ *
+ * This function is intended for architectures that need
+ * anything beyond simple page allocation or must have custom GFP flags.
+ *
+ * Return: `struct page` initialized as page table or %NULL on error
+ */
+static inline pgtable_t __pte_alloc_one(struct mm_struct *mm, gfp_t gfp)
+{
+ struct page *pte;
+
+ pte = alloc_page(gfp);
+ if (!pte)
+ return NULL;
+ if (!pgtable_page_ctor(pte)) {
+ __free_page(pte);
+ return NULL;
+ }
+
+ return pte;
+}
+
+#ifndef __HAVE_ARCH_PTE_ALLOC_ONE
+/**
+ * pte_alloc_one - allocate a page for PTE-level user page table
+ * @mm: the mm_struct of the current context
+ *
+ * Allocates a page and runs the pgtable_page_ctor().
+ *
+ * Return: `struct page` initialized as page table or %NULL on error
+ */
+static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
+{
+ return __pte_alloc_one(mm, GFP_PGTABLE_USER);
+}
#endif
+/*
+ * Should really implement gc for free page table pages. This could be
+ * done with a reference count in struct page.
+ */
+
+/**
+ * pte_free_kernel - free PTE-level user page table page
+ * @mm: the mm_struct of the current context
+ * @pte_page: the `struct page` representing the page table
+ */
+static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
+{
+ pgtable_page_dtor(pte_page);
+ __free_page(pte_page);
+}
+
+#else /* CONFIG_MMU */
+
+/* This is enough for a nommu architecture */
#define check_pgt_cache() do { } while (0)
+#endif /* CONFIG_MMU */
+
#endif /* __ASM_GENERIC_PGALLOC_H */
--
2.7.4
The nds32 implementation of pte_alloc_one_kernel() differs from the generic
in the use of __GFP_RETRY_MAYFAIL flag, which is removed after the
conversion.
The nds32 version of pte_alloc_one() missed the call to pgtable_page_ctor()
and also used __GFP_RETRY_MAYFAIL. Switching it to use generic
__pte_alloc_one() for the PTE page allocation ensures that page table
constructor is run and the user page tables are allocated with
__GFP_ACCOUNT.
The conversion to the generic version of pte_free_kernel() removes the NULL
check for pte.
The pte_free() version on nds32 is identical to the generic one and can be
simply dropped.
Signed-off-by: Mike Rapoport <[email protected]>
---
arch/nds32/include/asm/pgalloc.h | 31 ++++---------------------------
1 file changed, 4 insertions(+), 27 deletions(-)
diff --git a/arch/nds32/include/asm/pgalloc.h b/arch/nds32/include/asm/pgalloc.h
index 3c5fee5..954696c 100644
--- a/arch/nds32/include/asm/pgalloc.h
+++ b/arch/nds32/include/asm/pgalloc.h
@@ -9,6 +9,9 @@
#include <asm/tlbflush.h>
#include <asm/proc-fns.h>
+#define __HAVE_ARCH_PTE_ALLOC_ONE
+#include <asm-generic/pgalloc.h> /* for pte_{alloc,free}_one */
+
/*
* Since we have only two-level page tables, these are trivial
*/
@@ -22,22 +25,11 @@ extern void pgd_free(struct mm_struct *mm, pgd_t * pgd);
#define check_pgt_cache() do { } while (0)
-static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
-{
- pte_t *pte;
-
- pte =
- (pte_t *) __get_free_page(GFP_KERNEL | __GFP_RETRY_MAYFAIL |
- __GFP_ZERO);
-
- return pte;
-}
-
static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
{
pgtable_t pte;
- pte = alloc_pages(GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_ZERO, 0);
+ pte = __pte_alloc_one(mm, GFP_PGTABLE_USER);
if (pte)
cpu_dcache_wb_page((unsigned long)page_address(pte));
@@ -45,21 +37,6 @@ static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
}
/*
- * Free one PTE table.
- */
-static inline void pte_free_kernel(struct mm_struct *mm, pte_t * pte)
-{
- if (pte) {
- free_page((unsigned long)pte);
- }
-}
-
-static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
-{
- __free_page(pte);
-}
-
-/*
* Populate the pmdp entry with a pointer to the pte. This pmd is part
* of the mm address space.
*
--
2.7.4
The hexagon implementation pte_alloc_one(), pte_alloc_one_kernel(),
pte_free_kernel() and pte_free() is identical to the generic except of
lack of __GFP_ACCOUNT for the user PTEs allocation.
Switch hexagon to use generic version of these functions.
Signed-off-by: Mike Rapoport <[email protected]>
---
arch/hexagon/include/asm/pgalloc.h | 34 ++--------------------------------
1 file changed, 2 insertions(+), 32 deletions(-)
diff --git a/arch/hexagon/include/asm/pgalloc.h b/arch/hexagon/include/asm/pgalloc.h
index d361838..7661a26 100644
--- a/arch/hexagon/include/asm/pgalloc.h
+++ b/arch/hexagon/include/asm/pgalloc.h
@@ -24,6 +24,8 @@
#include <asm/mem-layout.h>
#include <asm/atomic.h>
+#include <asm-generic/pgalloc.h> /* for pte_{alloc,free}_one */
+
#define check_pgt_cache() do {} while (0)
extern unsigned long long kmap_generation;
@@ -59,38 +61,6 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
free_page((unsigned long) pgd);
}
-static inline struct page *pte_alloc_one(struct mm_struct *mm)
-{
- struct page *pte;
-
- pte = alloc_page(GFP_KERNEL | __GFP_ZERO);
- if (!pte)
- return NULL;
- if (!pgtable_page_ctor(pte)) {
- __free_page(pte);
- return NULL;
- }
- return pte;
-}
-
-/* _kernel variant gets to use a different allocator */
-static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
-{
- gfp_t flags = GFP_KERNEL | __GFP_ZERO;
- return (pte_t *) __get_free_page(flags);
-}
-
-static inline void pte_free(struct mm_struct *mm, struct page *pte)
-{
- pgtable_page_dtor(pte);
- __free_page(pte);
-}
-
-static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
-{
- free_page((unsigned long)pte);
-}
-
static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
pgtable_t pte)
{
--
2.7.4
Replace __get_free_page() and alloc_pages() calls with the generic
__pte_alloc_one_kernel() and __pte_alloc_one().
There is no functional change for the kernel PTE allocation.
The difference for the user PTEs, is that the clear_pte_table() is now
called after pgtable_page_ctor() and the addition of __GFP_ACCOUNT to the
GFP flags.
The conversion to the generic version of pte_free_kernel() removes the NULL
check for pte.
The pte_free() version on arm is identical to the generic one and can be
simply dropped.
Signed-off-by: Mike Rapoport <[email protected]>
---
arch/arm/include/asm/pgalloc.h | 41 +++++++++++++----------------------------
arch/arm/mm/mmu.c | 2 +-
2 files changed, 14 insertions(+), 29 deletions(-)
diff --git a/arch/arm/include/asm/pgalloc.h b/arch/arm/include/asm/pgalloc.h
index 17ab72f..13c5a9d 100644
--- a/arch/arm/include/asm/pgalloc.h
+++ b/arch/arm/include/asm/pgalloc.h
@@ -57,8 +57,6 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
extern pgd_t *pgd_alloc(struct mm_struct *mm);
extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
-#define PGALLOC_GFP (GFP_KERNEL | __GFP_ZERO)
-
static inline void clean_pte_table(pte_t *pte)
{
clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
@@ -80,54 +78,41 @@ static inline void clean_pte_table(pte_t *pte)
* | h/w pt 1 |
* +------------+
*/
+
+#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
+#define __HAVE_ARCH_PTE_ALLOC_ONE
+#include <asm-generic/pgalloc.h>
+
static inline pte_t *
pte_alloc_one_kernel(struct mm_struct *mm)
{
- pte_t *pte;
+ pte_t *pte = __pte_alloc_one_kernel(mm);
- pte = (pte_t *)__get_free_page(PGALLOC_GFP);
if (pte)
clean_pte_table(pte);
return pte;
}
+#ifdef CONFIG_HIGHPTE
+#define PGTABLE_HIGHMEM __GFP_HIGHMEM
+#else
+#define PGTABLE_HIGHMEM 0
+#endif
+
static inline pgtable_t
pte_alloc_one(struct mm_struct *mm)
{
struct page *pte;
-#ifdef CONFIG_HIGHPTE
- pte = alloc_pages(PGALLOC_GFP | __GFP_HIGHMEM, 0);
-#else
- pte = alloc_pages(PGALLOC_GFP, 0);
-#endif
+ pte = __pte_alloc_one(mm, GFP_PGTABLE_USER | PGTABLE_HIGHMEM);
if (!pte)
return NULL;
if (!PageHighMem(pte))
clean_pte_table(page_address(pte));
- if (!pgtable_page_ctor(pte)) {
- __free_page(pte);
- return NULL;
- }
return pte;
}
-/*
- * Free one PTE table.
- */
-static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
-{
- if (pte)
- free_page((unsigned long)pte);
-}
-
-static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
-{
- pgtable_page_dtor(pte);
- __free_page(pte);
-}
-
static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
pmdval_t prot)
{
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index f3ce341..e8e0382 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -732,7 +732,7 @@ static void __init *early_alloc(unsigned long sz)
static void *__init late_alloc(unsigned long sz)
{
- void *ptr = (void *)__get_free_pages(PGALLOC_GFP, get_order(sz));
+ void *ptr = (void *)__get_free_pages(GFP_PGTABLE_KERNEL, get_order(sz));
if (!ptr || !pgtable_page_ctor(virt_to_page(ptr)))
BUG();
--
2.7.4
alpha allocates PTE pages with __get_free_page() and uses
GFP_KERNEL | __GFP_ZERO for the allocations.
Switch it to the generic version that does exactly the same thing for the
kernel page tables and adds __GFP_ACCOUNT for the user PTEs.
The alpha pte_free() and pte_free_kernel() versions are identical to the
generic ones and can be simply dropped.
Signed-off-by: Mike Rapoport <[email protected]>
---
arch/alpha/include/asm/pgalloc.h | 40 +++-------------------------------------
1 file changed, 3 insertions(+), 37 deletions(-)
diff --git a/arch/alpha/include/asm/pgalloc.h b/arch/alpha/include/asm/pgalloc.h
index 02f9f91..71ded3b 100644
--- a/arch/alpha/include/asm/pgalloc.h
+++ b/arch/alpha/include/asm/pgalloc.h
@@ -5,6 +5,8 @@
#include <linux/mm.h>
#include <linux/mmzone.h>
+#include <asm-generic/pgalloc.h> /* for pte_{alloc,free}_one */
+
/*
* Allocate and free page tables. The xxx_kernel() versions are
* used to allocate a kernel page table - this turns on ASN bits
@@ -41,7 +43,7 @@ pgd_free(struct mm_struct *mm, pgd_t *pgd)
static inline pmd_t *
pmd_alloc_one(struct mm_struct *mm, unsigned long address)
{
- pmd_t *ret = (pmd_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
+ pmd_t *ret = (pmd_t *)__get_free_page(GFP_PGTABLE_USER);
return ret;
}
@@ -51,42 +53,6 @@ pmd_free(struct mm_struct *mm, pmd_t *pmd)
free_page((unsigned long)pmd);
}
-static inline pte_t *
-pte_alloc_one_kernel(struct mm_struct *mm)
-{
- pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
- return pte;
-}
-
-static inline void
-pte_free_kernel(struct mm_struct *mm, pte_t *pte)
-{
- free_page((unsigned long)pte);
-}
-
-static inline pgtable_t
-pte_alloc_one(struct mm_struct *mm)
-{
- pte_t *pte = pte_alloc_one_kernel(mm);
- struct page *page;
-
- if (!pte)
- return NULL;
- page = virt_to_page(pte);
- if (!pgtable_page_ctor(page)) {
- __free_page(page);
- return NULL;
- }
- return page;
-}
-
-static inline void
-pte_free(struct mm_struct *mm, pgtable_t page)
-{
- pgtable_page_dtor(page);
- __free_page(page);
-}
-
#define check_pgt_cache() do { } while (0)
#endif /* _ALPHA_PGALLOC_H */
--
2.7.4
Hi Mike,
On Thu, May 02, 2019 at 06:28:28PM +0300, Mike Rapoport wrote:
> +/**
> + * pte_free_kernel - free PTE-level user page table page
> + * @mm: the mm_struct of the current context
> + * @pte_page: the `struct page` representing the page table
> + */
> +static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
> +{
> + pgtable_page_dtor(pte_page);
> + __free_page(pte_page);
> +}
Nit: the comment names the wrong function (s/pte_free_kernel/pte_free/).
Thanks,
Paul
On 02/05/2019 16:28, Mike Rapoport wrote:
> um allocates PTE pages with __get_free_page() and uses
> GFP_KERNEL | __GFP_ZERO for the allocations.
>
> Switch it to the generic version that does exactly the same thing for the
> kernel page tables and adds __GFP_ACCOUNT for the user PTEs.
>
> The pte_free() and pte_free_kernel() versions are identical to the generic
> ones and can be simply dropped.
>
> Signed-off-by: Mike Rapoport <[email protected]>
> ---
> arch/um/include/asm/pgalloc.h | 16 ++--------------
> arch/um/kernel/mem.c | 22 ----------------------
> 2 files changed, 2 insertions(+), 36 deletions(-)
>
> diff --git a/arch/um/include/asm/pgalloc.h b/arch/um/include/asm/pgalloc.h
> index 99eb568..d7b282e 100644
> --- a/arch/um/include/asm/pgalloc.h
> +++ b/arch/um/include/asm/pgalloc.h
> @@ -10,6 +10,8 @@
>
> #include <linux/mm.h>
>
> +#include <asm-generic/pgalloc.h> /* for pte_{alloc,free}_one */
> +
> #define pmd_populate_kernel(mm, pmd, pte) \
> set_pmd(pmd, __pmd(_PAGE_TABLE + (unsigned long) __pa(pte)))
>
> @@ -25,20 +27,6 @@
> extern pgd_t *pgd_alloc(struct mm_struct *);
> extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
>
> -extern pte_t *pte_alloc_one_kernel(struct mm_struct *);
> -extern pgtable_t pte_alloc_one(struct mm_struct *);
> -
> -static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
> -{
> - free_page((unsigned long) pte);
> -}
> -
> -static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
> -{
> - pgtable_page_dtor(pte);
> - __free_page(pte);
> -}
> -
> #define __pte_free_tlb(tlb,pte, address) \
> do { \
> pgtable_page_dtor(pte); \
> diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
> index 99aa11b..2280374 100644
> --- a/arch/um/kernel/mem.c
> +++ b/arch/um/kernel/mem.c
> @@ -215,28 +215,6 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd)
> free_page((unsigned long) pgd);
> }
>
> -pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
> -{
> - pte_t *pte;
> -
> - pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
> - return pte;
> -}
> -
> -pgtable_t pte_alloc_one(struct mm_struct *mm)
> -{
> - struct page *pte;
> -
> - pte = alloc_page(GFP_KERNEL|__GFP_ZERO);
> - if (!pte)
> - return NULL;
> - if (!pgtable_page_ctor(pte)) {
> - __free_page(pte);
> - return NULL;
> - }
> - return pte;
> -}
> -
> #ifdef CONFIG_3_LEVEL_PGTABLES
> pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
> {
>
Reviewed-by: Anton Ivanov <[email protected]>
Acked-by: Anton Ivanov <[email protected]>
--
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/
On Thu, May 02, 2019 at 07:03:11PM +0000, Paul Burton wrote:
> Hi Mike,
>
> On Thu, May 02, 2019 at 06:28:28PM +0300, Mike Rapoport wrote:
> > +/**
> > + * pte_free_kernel - free PTE-level user page table page
> > + * @mm: the mm_struct of the current context
> > + * @pte_page: the `struct page` representing the page table
> > + */
> > +static inline void pte_free(struct mm_struct *mm, struct page *pte_page)
> > +{
> > + pgtable_page_dtor(pte_page);
> > + __free_page(pte_page);
> > +}
>
> Nit: the comment names the wrong function (s/pte_free_kernel/pte_free/).
Argh, evil copy-paste :)
Thanks!
> Thanks,
> Paul
>
--
Sincerely yours,
Mike.
Hi Mike,
Mike Rapoport <[email protected]> 於 2019年5月2日 週四 下午11:30寫道：
>
> The nds32 implementation of pte_alloc_one_kernel() differs from the generic
> in the use of __GFP_RETRY_MAYFAIL flag, which is removed after the
> conversion.
>
> The nds32 version of pte_alloc_one() missed the call to pgtable_page_ctor()
> and also used __GFP_RETRY_MAYFAIL. Switching it to use generic
> __pte_alloc_one() for the PTE page allocation ensures that page table
> constructor is run and the user page tables are allocated with
> __GFP_ACCOUNT.
>
> The conversion to the generic version of pte_free_kernel() removes the NULL
> check for pte.
>
> The pte_free() version on nds32 is identical to the generic one and can be
> simply dropped.
>
> Signed-off-by: Mike Rapoport <[email protected]>
> ---
> arch/nds32/include/asm/pgalloc.h | 31 ++++---------------------------
> 1 file changed, 4 insertions(+), 27 deletions(-)
Thanks for your patch.
I'm assuming this is going in along with the rest of the patches, so I'm not
going to add it to my tree.
Acked-by: Greentime Hu <[email protected]>