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* [PATCH V2 0/3] mm/hugetlb: Add some new generic fallbacks
@ 2020-05-06  6:12 Anshuman Khandual
  2020-05-06  6:12 ` [PATCH V2 1/3] arm64/mm: Drop __HAVE_ARCH_HUGE_PTEP_GET Anshuman Khandual
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Anshuman Khandual @ 2020-05-06  6:12 UTC (permalink / raw)
  To: linux-mm, akpm
  Cc: Anshuman Khandual, Russell King, Catalin Marinas, Will Deacon,
	Tony Luck, Fenghua Yu, Thomas Bogendoerfer, James E.J. Bottomley,
	Helge Deller, Benjamin Herrenschmidt, Paul Mackerras,
	Michael Ellerman, Paul Walmsley, Palmer Dabbelt, Heiko Carstens,
	Vasily Gorbik, Christian Borntraeger, Yoshinori Sato,
	Rich Felker, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, H. Peter Anvin, Mike Kravetz, x86,
	linux-arm-kernel, linux-ia64, linux-mips, linux-parisc,
	linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
	linux-arch, linux-kernel

This series adds the following new generic fallbacks. Before that it drops
__HAVE_ARCH_HUGE_PTEP_GET from arm64 platform.

1. is_hugepage_only_range()
2. arch_clear_hugepage_flags()

This has been boot tested on arm64 and x86 platforms but built tested on
some more platforms including the changed ones here. This series applies
on v5.7-rc4. After this arm (32 bit) remains the sole platform defining
it's own huge_ptep_get() via __HAVE_ARCH_HUGE_PTEP_GET.

Changes in V2:

- Adopted "#ifndef func" method (adding a single symbol to namespace) per Andrew
- Updated the commit messages in [PATCH 2/3] and [PATCH 3/3] as required

Changes in V1: (https://patchwork.kernel.org/project/linux-mm/list/?series=270677)

Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: x86@kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Anshuman Khandual (3):
  arm64/mm: Drop __HAVE_ARCH_HUGE_PTEP_GET
  mm/hugetlb: Define a generic fallback for is_hugepage_only_range()
  mm/hugetlb: Define a generic fallback for arch_clear_hugepage_flags()

 arch/arm/include/asm/hugetlb.h     |  7 +------
 arch/arm64/include/asm/hugetlb.h   | 13 +------------
 arch/ia64/include/asm/hugetlb.h    |  5 +----
 arch/mips/include/asm/hugetlb.h    | 11 -----------
 arch/parisc/include/asm/hugetlb.h  | 10 ----------
 arch/powerpc/include/asm/hugetlb.h |  5 +----
 arch/riscv/include/asm/hugetlb.h   | 10 ----------
 arch/s390/include/asm/hugetlb.h    |  8 +-------
 arch/sh/include/asm/hugetlb.h      |  7 +------
 arch/sparc/include/asm/hugetlb.h   | 10 ----------
 arch/x86/include/asm/hugetlb.h     | 10 ----------
 include/linux/hugetlb.h            | 14 ++++++++++++++
 12 files changed, 20 insertions(+), 90 deletions(-)

-- 
2.20.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH V2 1/3] arm64/mm: Drop __HAVE_ARCH_HUGE_PTEP_GET
  2020-05-06  6:12 [PATCH V2 0/3] mm/hugetlb: Add some new generic fallbacks Anshuman Khandual
@ 2020-05-06  6:12 ` Anshuman Khandual
  2020-05-06  7:43   ` Will Deacon
  2020-05-06  6:12 ` [PATCH V2 2/3] mm/hugetlb: Define a generic fallback for is_hugepage_only_range() Anshuman Khandual
  2020-05-06  6:12 ` [PATCH V2 3/3] mm/hugetlb: Define a generic fallback for arch_clear_hugepage_flags() Anshuman Khandual
  2 siblings, 1 reply; 6+ messages in thread
From: Anshuman Khandual @ 2020-05-06  6:12 UTC (permalink / raw)
  To: linux-mm, akpm
  Cc: Anshuman Khandual, Catalin Marinas, Will Deacon,
	linux-arm-kernel, linux-kernel

Platform specific huge_ptep_get() is required only when fetching the huge
PTE involves more than just dereferencing the page table pointer. This is
not the case on arm64 platform. Hence huge_ptep_pte() can be dropped along
with it's __HAVE_ARCH_HUGE_PTEP_GET subscription.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/arm64/include/asm/hugetlb.h | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index 2eb6c234d594..b88878ddc88b 100644
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -17,12 +17,6 @@
 extern bool arch_hugetlb_migration_supported(struct hstate *h);
 #endif
 
-#define __HAVE_ARCH_HUGE_PTEP_GET
-static inline pte_t huge_ptep_get(pte_t *ptep)
-{
-	return READ_ONCE(*ptep);
-}
-
 static inline int is_hugepage_only_range(struct mm_struct *mm,
 					 unsigned long addr, unsigned long len)
 {
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH V2 2/3] mm/hugetlb: Define a generic fallback for is_hugepage_only_range()
  2020-05-06  6:12 [PATCH V2 0/3] mm/hugetlb: Add some new generic fallbacks Anshuman Khandual
  2020-05-06  6:12 ` [PATCH V2 1/3] arm64/mm: Drop __HAVE_ARCH_HUGE_PTEP_GET Anshuman Khandual
@ 2020-05-06  6:12 ` Anshuman Khandual
  2020-05-06  6:12 ` [PATCH V2 3/3] mm/hugetlb: Define a generic fallback for arch_clear_hugepage_flags() Anshuman Khandual
  2 siblings, 0 replies; 6+ messages in thread
From: Anshuman Khandual @ 2020-05-06  6:12 UTC (permalink / raw)
  To: linux-mm, akpm
  Cc: Anshuman Khandual, Russell King, Catalin Marinas, Will Deacon,
	Tony Luck, Fenghua Yu, Thomas Bogendoerfer, James E.J. Bottomley,
	Helge Deller, Benjamin Herrenschmidt, Paul Mackerras,
	Michael Ellerman, Paul Walmsley, Palmer Dabbelt, Heiko Carstens,
	Vasily Gorbik, Christian Borntraeger, Yoshinori Sato,
	Rich Felker, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, H. Peter Anvin, Mike Kravetz, x86,
	linux-arm-kernel, linux-ia64, linux-mips, linux-parisc,
	linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
	linux-arch, linux-kernel

There are multiple similar definitions for is_hugepage_only_range() on
various platforms. Lets just add it's generic fallback definition for
platforms that do not override. This help reduce code duplication.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: x86@kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/arm/include/asm/hugetlb.h     | 6 ------
 arch/arm64/include/asm/hugetlb.h   | 6 ------
 arch/ia64/include/asm/hugetlb.h    | 1 +
 arch/mips/include/asm/hugetlb.h    | 7 -------
 arch/parisc/include/asm/hugetlb.h  | 6 ------
 arch/powerpc/include/asm/hugetlb.h | 1 +
 arch/riscv/include/asm/hugetlb.h   | 6 ------
 arch/s390/include/asm/hugetlb.h    | 7 -------
 arch/sh/include/asm/hugetlb.h      | 6 ------
 arch/sparc/include/asm/hugetlb.h   | 6 ------
 arch/x86/include/asm/hugetlb.h     | 6 ------
 include/linux/hugetlb.h            | 9 +++++++++
 12 files changed, 11 insertions(+), 56 deletions(-)

diff --git a/arch/arm/include/asm/hugetlb.h b/arch/arm/include/asm/hugetlb.h
index 318dcf5921ab..9ecd516d1ff7 100644
--- a/arch/arm/include/asm/hugetlb.h
+++ b/arch/arm/include/asm/hugetlb.h
@@ -14,12 +14,6 @@
 #include <asm/hugetlb-3level.h>
 #include <asm-generic/hugetlb.h>
 
-static inline int is_hugepage_only_range(struct mm_struct *mm,
-					 unsigned long addr, unsigned long len)
-{
-	return 0;
-}
-
 static inline void arch_clear_hugepage_flags(struct page *page)
 {
 	clear_bit(PG_dcache_clean, &page->flags);
diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index b88878ddc88b..8f58e052697a 100644
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -17,12 +17,6 @@
 extern bool arch_hugetlb_migration_supported(struct hstate *h);
 #endif
 
-static inline int is_hugepage_only_range(struct mm_struct *mm,
-					 unsigned long addr, unsigned long len)
-{
-	return 0;
-}
-
 static inline void arch_clear_hugepage_flags(struct page *page)
 {
 	clear_bit(PG_dcache_clean, &page->flags);
diff --git a/arch/ia64/include/asm/hugetlb.h b/arch/ia64/include/asm/hugetlb.h
index 36cc0396b214..6ef50b9a4bdf 100644
--- a/arch/ia64/include/asm/hugetlb.h
+++ b/arch/ia64/include/asm/hugetlb.h
@@ -20,6 +20,7 @@ static inline int is_hugepage_only_range(struct mm_struct *mm,
 	return (REGION_NUMBER(addr) == RGN_HPAGE ||
 		REGION_NUMBER((addr)+(len)-1) == RGN_HPAGE);
 }
+#define is_hugepage_only_range is_hugepage_only_range
 
 #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
 static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
diff --git a/arch/mips/include/asm/hugetlb.h b/arch/mips/include/asm/hugetlb.h
index 425bb6fc3bda..8b201e281f67 100644
--- a/arch/mips/include/asm/hugetlb.h
+++ b/arch/mips/include/asm/hugetlb.h
@@ -11,13 +11,6 @@
 
 #include <asm/page.h>
 
-static inline int is_hugepage_only_range(struct mm_struct *mm,
-					 unsigned long addr,
-					 unsigned long len)
-{
-	return 0;
-}
-
 #define __HAVE_ARCH_PREPARE_HUGEPAGE_RANGE
 static inline int prepare_hugepage_range(struct file *file,
 					 unsigned long addr,
diff --git a/arch/parisc/include/asm/hugetlb.h b/arch/parisc/include/asm/hugetlb.h
index 7cb595dcb7d7..411d9d867baa 100644
--- a/arch/parisc/include/asm/hugetlb.h
+++ b/arch/parisc/include/asm/hugetlb.h
@@ -12,12 +12,6 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 			      pte_t *ptep);
 
-static inline int is_hugepage_only_range(struct mm_struct *mm,
-					 unsigned long addr,
-					 unsigned long len) {
-	return 0;
-}
-
 /*
  * If the arch doesn't supply something else, assume that hugepage
  * size aligned regions are ok without further preparation.
diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index bd6504c28c2f..b167c869d72d 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -30,6 +30,7 @@ static inline int is_hugepage_only_range(struct mm_struct *mm,
 		return slice_is_hugepage_only_range(mm, addr, len);
 	return 0;
 }
+#define is_hugepage_only_range is_hugepage_only_range
 
 #define __HAVE_ARCH_HUGETLB_FREE_PGD_RANGE
 void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
index 728a5db66597..866f6ae6467c 100644
--- a/arch/riscv/include/asm/hugetlb.h
+++ b/arch/riscv/include/asm/hugetlb.h
@@ -5,12 +5,6 @@
 #include <asm-generic/hugetlb.h>
 #include <asm/page.h>
 
-static inline int is_hugepage_only_range(struct mm_struct *mm,
-					 unsigned long addr,
-					 unsigned long len) {
-	return 0;
-}
-
 static inline void arch_clear_hugepage_flags(struct page *page)
 {
 }
diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index de8f0bf5f238..7d27ea96ec2f 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -21,13 +21,6 @@ pte_t huge_ptep_get(pte_t *ptep);
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
 			      unsigned long addr, pte_t *ptep);
 
-static inline bool is_hugepage_only_range(struct mm_struct *mm,
-					  unsigned long addr,
-					  unsigned long len)
-{
-	return false;
-}
-
 /*
  * If the arch doesn't supply something else, assume that hugepage
  * size aligned regions are ok without further preparation.
diff --git a/arch/sh/include/asm/hugetlb.h b/arch/sh/include/asm/hugetlb.h
index 6f025fe18146..536ad2cb8aa4 100644
--- a/arch/sh/include/asm/hugetlb.h
+++ b/arch/sh/include/asm/hugetlb.h
@@ -5,12 +5,6 @@
 #include <asm/cacheflush.h>
 #include <asm/page.h>
 
-static inline int is_hugepage_only_range(struct mm_struct *mm,
-					 unsigned long addr,
-					 unsigned long len) {
-	return 0;
-}
-
 /*
  * If the arch doesn't supply something else, assume that hugepage
  * size aligned regions are ok without further preparation.
diff --git a/arch/sparc/include/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
index 3963f80d1cb3..a056fe1119f5 100644
--- a/arch/sparc/include/asm/hugetlb.h
+++ b/arch/sparc/include/asm/hugetlb.h
@@ -20,12 +20,6 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 			      pte_t *ptep);
 
-static inline int is_hugepage_only_range(struct mm_struct *mm,
-					 unsigned long addr,
-					 unsigned long len) {
-	return 0;
-}
-
 #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
 static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
 					 unsigned long addr, pte_t *ptep)
diff --git a/arch/x86/include/asm/hugetlb.h b/arch/x86/include/asm/hugetlb.h
index f65cfb48cfdd..cc98f79074d0 100644
--- a/arch/x86/include/asm/hugetlb.h
+++ b/arch/x86/include/asm/hugetlb.h
@@ -7,12 +7,6 @@
 
 #define hugepages_supported() boot_cpu_has(X86_FEATURE_PSE)
 
-static inline int is_hugepage_only_range(struct mm_struct *mm,
-					 unsigned long addr,
-					 unsigned long len) {
-	return 0;
-}
-
 static inline void arch_clear_hugepage_flags(struct page *page)
 {
 }
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 43a1cef8f0f1..c01c0c6f7fd4 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -591,6 +591,15 @@ static inline unsigned int blocks_per_huge_page(struct hstate *h)
 
 #include <asm/hugetlb.h>
 
+#ifndef is_hugepage_only_range
+static inline int is_hugepage_only_range(struct mm_struct *mm,
+					unsigned long addr, unsigned long len)
+{
+	return 0;
+}
+#define is_hugepage_only_range is_hugepage_only_range
+#endif
+
 #ifndef arch_make_huge_pte
 static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
 				       struct page *page, int writable)
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH V2 3/3] mm/hugetlb: Define a generic fallback for arch_clear_hugepage_flags()
  2020-05-06  6:12 [PATCH V2 0/3] mm/hugetlb: Add some new generic fallbacks Anshuman Khandual
  2020-05-06  6:12 ` [PATCH V2 1/3] arm64/mm: Drop __HAVE_ARCH_HUGE_PTEP_GET Anshuman Khandual
  2020-05-06  6:12 ` [PATCH V2 2/3] mm/hugetlb: Define a generic fallback for is_hugepage_only_range() Anshuman Khandual
@ 2020-05-06  6:12 ` Anshuman Khandual
  2 siblings, 0 replies; 6+ messages in thread
From: Anshuman Khandual @ 2020-05-06  6:12 UTC (permalink / raw)
  To: linux-mm, akpm
  Cc: Anshuman Khandual, Russell King, Catalin Marinas, Will Deacon,
	Tony Luck, Fenghua Yu, Thomas Bogendoerfer, James E.J. Bottomley,
	Helge Deller, Benjamin Herrenschmidt, Paul Mackerras,
	Michael Ellerman, Paul Walmsley, Palmer Dabbelt, Heiko Carstens,
	Vasily Gorbik, Christian Borntraeger, Yoshinori Sato,
	Rich Felker, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, H. Peter Anvin, Mike Kravetz, x86,
	linux-arm-kernel, linux-ia64, linux-mips, linux-parisc,
	linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
	linux-arch, linux-kernel

There are multiple similar definitions for arch_clear_hugepage_flags() on
various platforms. Lets just add it's generic fallback definition for
platforms that do not override. This help reduce code duplication.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: x86@kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/arm/include/asm/hugetlb.h     | 1 +
 arch/arm64/include/asm/hugetlb.h   | 1 +
 arch/ia64/include/asm/hugetlb.h    | 4 ----
 arch/mips/include/asm/hugetlb.h    | 4 ----
 arch/parisc/include/asm/hugetlb.h  | 4 ----
 arch/powerpc/include/asm/hugetlb.h | 4 ----
 arch/riscv/include/asm/hugetlb.h   | 4 ----
 arch/s390/include/asm/hugetlb.h    | 1 +
 arch/sh/include/asm/hugetlb.h      | 1 +
 arch/sparc/include/asm/hugetlb.h   | 4 ----
 arch/x86/include/asm/hugetlb.h     | 4 ----
 include/linux/hugetlb.h            | 5 +++++
 12 files changed, 9 insertions(+), 28 deletions(-)

diff --git a/arch/arm/include/asm/hugetlb.h b/arch/arm/include/asm/hugetlb.h
index 9ecd516d1ff7..d02d6ca88e92 100644
--- a/arch/arm/include/asm/hugetlb.h
+++ b/arch/arm/include/asm/hugetlb.h
@@ -18,5 +18,6 @@ static inline void arch_clear_hugepage_flags(struct page *page)
 {
 	clear_bit(PG_dcache_clean, &page->flags);
 }
+#define arch_clear_hugepage_flags arch_clear_hugepage_flags
 
 #endif /* _ASM_ARM_HUGETLB_H */
diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index 8f58e052697a..94ba0c5bced2 100644
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -21,6 +21,7 @@ static inline void arch_clear_hugepage_flags(struct page *page)
 {
 	clear_bit(PG_dcache_clean, &page->flags);
 }
+#define arch_clear_hugepage_flags arch_clear_hugepage_flags
 
 extern pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
 				struct page *page, int writable);
diff --git a/arch/ia64/include/asm/hugetlb.h b/arch/ia64/include/asm/hugetlb.h
index 6ef50b9a4bdf..7e46ebde8c0c 100644
--- a/arch/ia64/include/asm/hugetlb.h
+++ b/arch/ia64/include/asm/hugetlb.h
@@ -28,10 +28,6 @@ static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
 {
 }
 
-static inline void arch_clear_hugepage_flags(struct page *page)
-{
-}
-
 #include <asm-generic/hugetlb.h>
 
 #endif /* _ASM_IA64_HUGETLB_H */
diff --git a/arch/mips/include/asm/hugetlb.h b/arch/mips/include/asm/hugetlb.h
index 8b201e281f67..10e3be870df7 100644
--- a/arch/mips/include/asm/hugetlb.h
+++ b/arch/mips/include/asm/hugetlb.h
@@ -75,10 +75,6 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 	return changed;
 }
 
-static inline void arch_clear_hugepage_flags(struct page *page)
-{
-}
-
 #include <asm-generic/hugetlb.h>
 
 #endif /* __ASM_HUGETLB_H */
diff --git a/arch/parisc/include/asm/hugetlb.h b/arch/parisc/include/asm/hugetlb.h
index 411d9d867baa..a69cf9efb0c1 100644
--- a/arch/parisc/include/asm/hugetlb.h
+++ b/arch/parisc/include/asm/hugetlb.h
@@ -42,10 +42,6 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 					     unsigned long addr, pte_t *ptep,
 					     pte_t pte, int dirty);
 
-static inline void arch_clear_hugepage_flags(struct page *page)
-{
-}
-
 #include <asm-generic/hugetlb.h>
 
 #endif /* _ASM_PARISC64_HUGETLB_H */
diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index b167c869d72d..e6dfa63da552 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -61,10 +61,6 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 			       unsigned long addr, pte_t *ptep,
 			       pte_t pte, int dirty);
 
-static inline void arch_clear_hugepage_flags(struct page *page)
-{
-}
-
 #include <asm-generic/hugetlb.h>
 
 #else /* ! CONFIG_HUGETLB_PAGE */
diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
index 866f6ae6467c..a5c2ca1d1cd8 100644
--- a/arch/riscv/include/asm/hugetlb.h
+++ b/arch/riscv/include/asm/hugetlb.h
@@ -5,8 +5,4 @@
 #include <asm-generic/hugetlb.h>
 #include <asm/page.h>
 
-static inline void arch_clear_hugepage_flags(struct page *page)
-{
-}
-
 #endif /* _ASM_RISCV_HUGETLB_H */
diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index 7d27ea96ec2f..9ddf4a43a590 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -39,6 +39,7 @@ static inline void arch_clear_hugepage_flags(struct page *page)
 {
 	clear_bit(PG_arch_1, &page->flags);
 }
+#define arch_clear_hugepage_flags arch_clear_hugepage_flags
 
 static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
 				  pte_t *ptep, unsigned long sz)
diff --git a/arch/sh/include/asm/hugetlb.h b/arch/sh/include/asm/hugetlb.h
index 536ad2cb8aa4..ae4de7b89210 100644
--- a/arch/sh/include/asm/hugetlb.h
+++ b/arch/sh/include/asm/hugetlb.h
@@ -30,6 +30,7 @@ static inline void arch_clear_hugepage_flags(struct page *page)
 {
 	clear_bit(PG_dcache_clean, &page->flags);
 }
+#define arch_clear_hugepage_flags arch_clear_hugepage_flags
 
 #include <asm-generic/hugetlb.h>
 
diff --git a/arch/sparc/include/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
index a056fe1119f5..53838a173f62 100644
--- a/arch/sparc/include/asm/hugetlb.h
+++ b/arch/sparc/include/asm/hugetlb.h
@@ -47,10 +47,6 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 	return changed;
 }
 
-static inline void arch_clear_hugepage_flags(struct page *page)
-{
-}
-
 #define __HAVE_ARCH_HUGETLB_FREE_PGD_RANGE
 void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
 			    unsigned long end, unsigned long floor,
diff --git a/arch/x86/include/asm/hugetlb.h b/arch/x86/include/asm/hugetlb.h
index cc98f79074d0..1721b1aadeb1 100644
--- a/arch/x86/include/asm/hugetlb.h
+++ b/arch/x86/include/asm/hugetlb.h
@@ -7,8 +7,4 @@
 
 #define hugepages_supported() boot_cpu_has(X86_FEATURE_PSE)
 
-static inline void arch_clear_hugepage_flags(struct page *page)
-{
-}
-
 #endif /* _ASM_X86_HUGETLB_H */
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index c01c0c6f7fd4..04bc794becfc 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -600,6 +600,11 @@ static inline int is_hugepage_only_range(struct mm_struct *mm,
 #define is_hugepage_only_range is_hugepage_only_range
 #endif
 
+#ifndef arch_clear_hugepage_flags
+static inline void arch_clear_hugepage_flags(struct page *page) { }
+#define arch_clear_hugepage_flags arch_clear_hugepage_flags
+#endif
+
 #ifndef arch_make_huge_pte
 static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
 				       struct page *page, int writable)
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH V2 1/3] arm64/mm: Drop __HAVE_ARCH_HUGE_PTEP_GET
  2020-05-06  6:12 ` [PATCH V2 1/3] arm64/mm: Drop __HAVE_ARCH_HUGE_PTEP_GET Anshuman Khandual
@ 2020-05-06  7:43   ` Will Deacon
  2020-05-06 10:21     ` Anshuman Khandual
  0 siblings, 1 reply; 6+ messages in thread
From: Will Deacon @ 2020-05-06  7:43 UTC (permalink / raw)
  To: Anshuman Khandual
  Cc: linux-mm, akpm, Catalin Marinas, linux-arm-kernel, linux-kernel

On Wed, May 06, 2020 at 11:42:12AM +0530, Anshuman Khandual wrote:
> Platform specific huge_ptep_get() is required only when fetching the huge
> PTE involves more than just dereferencing the page table pointer. This is
> not the case on arm64 platform. Hence huge_ptep_pte() can be dropped along
> with it's __HAVE_ARCH_HUGE_PTEP_GET subscription.
> 
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
>  arch/arm64/include/asm/hugetlb.h | 6 ------
>  1 file changed, 6 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
> index 2eb6c234d594..b88878ddc88b 100644
> --- a/arch/arm64/include/asm/hugetlb.h
> +++ b/arch/arm64/include/asm/hugetlb.h
> @@ -17,12 +17,6 @@
>  extern bool arch_hugetlb_migration_supported(struct hstate *h);
>  #endif
>  
> -#define __HAVE_ARCH_HUGE_PTEP_GET
> -static inline pte_t huge_ptep_get(pte_t *ptep)
> -{
> -	return READ_ONCE(*ptep);
> -}

Hmm, I'm nervous about dropping the READ_ONCE() here. We added them after
running into page-table issues with THP [1] and it's really important to
use them consistently to avoid hitting that again.

If the generic code used READ_ONCE(), I'd be happy to switch to it.

Will

[1] https://lore.kernel.org/lkml/1506527369-19535-1-git-send-email-will.deacon@arm.com/

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH V2 1/3] arm64/mm: Drop __HAVE_ARCH_HUGE_PTEP_GET
  2020-05-06  7:43   ` Will Deacon
@ 2020-05-06 10:21     ` Anshuman Khandual
  0 siblings, 0 replies; 6+ messages in thread
From: Anshuman Khandual @ 2020-05-06 10:21 UTC (permalink / raw)
  To: Will Deacon
  Cc: linux-mm, akpm, Catalin Marinas, linux-arm-kernel, linux-kernel



On 05/06/2020 01:13 PM, Will Deacon wrote:
> On Wed, May 06, 2020 at 11:42:12AM +0530, Anshuman Khandual wrote:
>> Platform specific huge_ptep_get() is required only when fetching the huge
>> PTE involves more than just dereferencing the page table pointer. This is
>> not the case on arm64 platform. Hence huge_ptep_pte() can be dropped along
>> with it's __HAVE_ARCH_HUGE_PTEP_GET subscription.
>>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: linux-arm-kernel@lists.infradead.org
>> Cc: linux-mm@kvack.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>>  arch/arm64/include/asm/hugetlb.h | 6 ------
>>  1 file changed, 6 deletions(-)
>>
>> diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
>> index 2eb6c234d594..b88878ddc88b 100644
>> --- a/arch/arm64/include/asm/hugetlb.h
>> +++ b/arch/arm64/include/asm/hugetlb.h
>> @@ -17,12 +17,6 @@
>>  extern bool arch_hugetlb_migration_supported(struct hstate *h);
>>  #endif
>>  
>> -#define __HAVE_ARCH_HUGE_PTEP_GET
>> -static inline pte_t huge_ptep_get(pte_t *ptep)
>> -{
>> -	return READ_ONCE(*ptep);
>> -}
> 
> Hmm, I'm nervous about dropping the READ_ONCE() here. We added them after
> running into page-table issues with THP [1] and it's really important to
> use them consistently to avoid hitting that again.
> 
> If the generic code used READ_ONCE(), I'd be happy to switch to it.

Sure, will add READ_ONCE() in the generic huge_ptep_get(). AFAICS it should
not cause any problem for other platforms (but let me know otherwise).

> 
> Will
> 
> [1] https://lore.kernel.org/lkml/1506527369-19535-1-git-send-email-will.deacon@arm.com/
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-05-06 10:22 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-05-06  6:12 [PATCH V2 0/3] mm/hugetlb: Add some new generic fallbacks Anshuman Khandual
2020-05-06  6:12 ` [PATCH V2 1/3] arm64/mm: Drop __HAVE_ARCH_HUGE_PTEP_GET Anshuman Khandual
2020-05-06  7:43   ` Will Deacon
2020-05-06 10:21     ` Anshuman Khandual
2020-05-06  6:12 ` [PATCH V2 2/3] mm/hugetlb: Define a generic fallback for is_hugepage_only_range() Anshuman Khandual
2020-05-06  6:12 ` [PATCH V2 3/3] mm/hugetlb: Define a generic fallback for arch_clear_hugepage_flags() Anshuman Khandual

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