Ok, I tried every defconfig available:

- for the nohash/32, I found that I could use mpc885_ads_defconfig and I 
activated HUGETLBFS.
I removed the definition of huge_ptep_set_wrprotect from 
nohash/32/pgtable.h, add an #error in
include/asm-generic/hugetlb.h right before the generic definition of 
huge_ptep_set_wrprotect,
and fell onto it at compile-time:
=> I'm pretty confident then that removing the definition of 
huge_ptep_set_wrprotect does not
break anythingin this case.

- regardind book3s/32, I did not find any defconfig with 
CONFIG_PPC_BOOK3S_32, CONFIG_PPC32
allowing to enable huge page support (ie CONFIG_SYS_SUPPORTS_HUGETLBFS)
=> Do you have a defconfig that would allow me to try the same as above ?

Thanks,

Alex


On 07/31/2018 11:17 AM, Alexandre Ghiti wrote:

On 07/31/2018 12:06 PM, Michael Ellerman wrote:

quoted

Alexandre Ghiti [off-list ref] writes:

quoted

arm, ia64, mips, sh, x86 architectures use the same version
of huge_ptep_set_wrprotect, so move this generic implementation into
asm-generic/hugetlb.h.
Note: powerpc uses twice for book3s/32 and nohash/32 the same 
version as
the above architectures, but the modification was not straightforward
and hence has not been done.

Do you remember what the problem was there?

It looks like you should just be able to drop them like the others. I
assume there's some header spaghetti that causes problems though?

Yes, the header spaghetti frightened me a bit. Maybe I should have 
tried harder: I can try to remove them and find the right defconfigs 
to compile both to begin with. And to guarantee the functionality is 
preserved, can I use the testsuite of libhugetlbfs with qemu ?

Alex

quoted

cheers

quoted

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Mike Kravetz <redacted>
---
  arch/arm/include/asm/hugetlb-3level.h        | 6 ------
  arch/arm64/include/asm/hugetlb.h             | 1 +
  arch/ia64/include/asm/hugetlb.h              | 6 ------
  arch/mips/include/asm/hugetlb.h              | 6 ------
  arch/parisc/include/asm/hugetlb.h            | 1 +
  arch/powerpc/include/asm/book3s/32/pgtable.h | 2 ++
  arch/powerpc/include/asm/book3s/64/pgtable.h | 1 +
  arch/powerpc/include/asm/nohash/32/pgtable.h | 2 ++
  arch/powerpc/include/asm/nohash/64/pgtable.h | 1 +
  arch/sh/include/asm/hugetlb.h                | 6 ------
  arch/sparc/include/asm/hugetlb.h             | 1 +
  arch/x86/include/asm/hugetlb.h               | 6 ------
  include/asm-generic/hugetlb.h                | 8 ++++++++
  13 files changed, 17 insertions(+), 30 deletions(-)

diff --git a/arch/arm/include/asm/hugetlb-3level.h 

b/arch/arm/include/asm/hugetlb-3level.h
index b897541520ef..8247cd6a2ac6 100644

--- a/arch/arm/include/asm/hugetlb-3level.h
+++ b/arch/arm/include/asm/hugetlb-3level.h

@@ -37,12 +37,6 @@ static inline pte_t huge_ptep_get(pte_t *ptep)

      return retval;
  }
  -static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
-                       unsigned long addr, pte_t *ptep)
-{
-    ptep_set_wrprotect(mm, addr, ptep);
-}
-
  static inline int huge_ptep_set_access_flags(struct vm_area_struct 
*vma,
                           unsigned long addr, pte_t *ptep,
                           pte_t pte, int dirty)

diff --git a/arch/arm64/include/asm/hugetlb.h 

b/arch/arm64/include/asm/hugetlb.h
index 3e7f6e69b28d..f4f69ae5466e 100644

--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h

@@ -48,6 +48,7 @@ extern int huge_ptep_set_access_flags(struct 

vm_area_struct *vma,
  #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
  extern pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
                       unsigned long addr, pte_t *ptep);
+#define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
  extern void huge_ptep_set_wrprotect(struct mm_struct *mm,
                      unsigned long addr, pte_t *ptep);
  #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH

diff --git a/arch/ia64/include/asm/hugetlb.h 

b/arch/ia64/include/asm/hugetlb.h
index cbe296271030..49d1f7949f3a 100644

--- a/arch/ia64/include/asm/hugetlb.h
+++ b/arch/ia64/include/asm/hugetlb.h

@@ -27,12 +27,6 @@ static inline void huge_ptep_clear_flush(struct 

vm_area_struct *vma,
  {
  }
  -static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
-                       unsigned long addr, pte_t *ptep)
-{
-    ptep_set_wrprotect(mm, addr, ptep);
-}
-
  static inline int huge_ptep_set_access_flags(struct vm_area_struct 
*vma,
                           unsigned long addr, pte_t *ptep,
                           pte_t pte, int dirty)

diff --git a/arch/mips/include/asm/hugetlb.h 

b/arch/mips/include/asm/hugetlb.h
index 6ff2531cfb1d..3dcf5debf8c4 100644

--- a/arch/mips/include/asm/hugetlb.h
+++ b/arch/mips/include/asm/hugetlb.h

@@ -63,12 +63,6 @@ static inline int huge_pte_none(pte_t pte)

      return !val || (val == (unsigned long)invalid_pte_table);
  }
  -static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
-                       unsigned long addr, pte_t *ptep)
-{
-    ptep_set_wrprotect(mm, addr, ptep);
-}
-
  static inline int huge_ptep_set_access_flags(struct vm_area_struct 
*vma,
                           unsigned long addr,
                           pte_t *ptep, pte_t pte,

diff --git a/arch/parisc/include/asm/hugetlb.h 

b/arch/parisc/include/asm/hugetlb.h
index fb7e0fd858a3..9c3950ca2974 100644

--- a/arch/parisc/include/asm/hugetlb.h
+++ b/arch/parisc/include/asm/hugetlb.h

@@ -39,6 +39,7 @@ static inline void huge_ptep_clear_flush(struct 

vm_area_struct *vma,
  {
  }
  +#define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
  void huge_ptep_set_wrprotect(struct mm_struct *mm,
                         unsigned long addr, pte_t *ptep);
  diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h 
b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 02f5acd7ccc4..d2cd1d0226e9 100644

--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h

@@ -228,6 +228,8 @@ static inline void ptep_set_wrprotect(struct 

mm_struct *mm, unsigned long addr,
  {
      pte_update(ptep, (_PAGE_RW | _PAGE_HWWRITE), _PAGE_RO);
  }
+
+#define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
  static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
                         unsigned long addr, pte_t *ptep)
  {

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h 

b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 42aafba7a308..7d957f7c47cd 100644

--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h

@@ -451,6 +451,7 @@ static inline void ptep_set_wrprotect(struct 

mm_struct *mm, unsigned long addr,
          pte_update(mm, addr, ptep, 0, _PAGE_PRIVILEGED, 0);
  }
  +#define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
  static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
                         unsigned long addr, pte_t *ptep)
  {

diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h 

b/arch/powerpc/include/asm/nohash/32/pgtable.h
index 7c46a98cc7f4..f39e200d9591 100644

--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h

@@ -249,6 +249,8 @@ static inline void ptep_set_wrprotect(struct 

mm_struct *mm, unsigned long addr,
  {
      pte_update(ptep, (_PAGE_RW | _PAGE_HWWRITE), _PAGE_RO);
  }
+
+#define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
  static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
                         unsigned long addr, pte_t *ptep)
  {

diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h 

b/arch/powerpc/include/asm/nohash/64/pgtable.h
index dd0c7236208f..69fbf7e9b4db 100644

--- a/arch/powerpc/include/asm/nohash/64/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable.h

@@ -238,6 +238,7 @@ static inline void ptep_set_wrprotect(struct 

mm_struct *mm, unsigned long addr,
      pte_update(mm, addr, ptep, _PAGE_RW, 0, 0);
  }
  +#define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
  static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
                         unsigned long addr, pte_t *ptep)
  {

diff --git a/arch/sh/include/asm/hugetlb.h 

b/arch/sh/include/asm/hugetlb.h
index f1bbd255ee43..8df4004977b9 100644

--- a/arch/sh/include/asm/hugetlb.h
+++ b/arch/sh/include/asm/hugetlb.h

@@ -32,12 +32,6 @@ static inline void huge_ptep_clear_flush(struct 

vm_area_struct *vma,
  {
  }
  -static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
-                       unsigned long addr, pte_t *ptep)
-{
-    ptep_set_wrprotect(mm, addr, ptep);
-}
-
  static inline int huge_ptep_set_access_flags(struct vm_area_struct 
*vma,
                           unsigned long addr, pte_t *ptep,
                           pte_t pte, int dirty)

diff --git a/arch/sparc/include/asm/hugetlb.h 

b/arch/sparc/include/asm/hugetlb.h
index 2101ea217f33..c41754a113f3 100644

--- a/arch/sparc/include/asm/hugetlb.h
+++ b/arch/sparc/include/asm/hugetlb.h

@@ -32,6 +32,7 @@ static inline void huge_ptep_clear_flush(struct 

vm_area_struct *vma,
  {
  }
  +#define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
  static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
                         unsigned long addr, pte_t *ptep)
  {

diff --git a/arch/x86/include/asm/hugetlb.h 

b/arch/x86/include/asm/hugetlb.h
index 59c056adb3c9..a3f781f7a264 100644

--- a/arch/x86/include/asm/hugetlb.h
+++ b/arch/x86/include/asm/hugetlb.h

@@ -13,12 +13,6 @@ static inline int is_hugepage_only_range(struct 

mm_struct *mm,
      return 0;
  }
  -static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
-                       unsigned long addr, pte_t *ptep)
-{
-    ptep_set_wrprotect(mm, addr, ptep);
-}
-
  static inline int huge_ptep_set_access_flags(struct vm_area_struct 
*vma,
                           unsigned long addr, pte_t *ptep,
                           pte_t pte, int dirty)

diff --git a/include/asm-generic/hugetlb.h 

b/include/asm-generic/hugetlb.h
index 6c0c8b0c71e0..9b9039845278 100644

--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h

@@ -102,4 +102,12 @@ static inline int prepare_hugepage_range(struct 

file *file,
  }
  #endif
  +#ifndef __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
+static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
+        unsigned long addr, pte_t *ptep)
+{
+    ptep_set_wrprotect(mm, addr, ptep);
+}
+#endif
+
  #endif /* _ASM_GENERIC_HUGETLB_H */
-- 
2.16.2