Re: [PATCH] mm: move huge_pmd_set_accessed out of huge_memory.c

On 4/21/2016 2:15 AM, Hugh Dickins wrote:

On Wed, 20 Apr 2016, Shi, Yang wrote:

...

Hi folks,

I didn't realize pmd_* functions are protected by CONFIG_TRANSPARENT_HUGEPAGE on the most architectures before I made this change.

Before I fix all the affected architectures code, I want to check if you guys think this change is worth or not?

Thanks for asking: no, it is not worthwhile.

I would much prefer not to have to consider these trivial cleanups in the huge memory area at this time. Kirill and I have urgent work to do in this area, and coping with patch conflicts between different versions of the source will not help any of us.

Thanks for your suggestion. I would consider to put such cleanup work on the back burner.

Yang

Thanks, Hugh

...

Thanks, Yang

On 4/20/2016 11:24 AM, Yang Shi wrote:

...

huge_pmd_set_accessed is only called by __handle_mm_fault from memory.c, move the definition to memory.c and make it static like create_huge_pmd and wp_huge_pmd.

Signed-off-by: Yang Shi yang.shi@linaro.org

include/linux/huge_mm.h | 4 ---- mm/huge_memory.c | 23 ----------------------- mm/memory.c | 23 +++++++++++++++++++++++ 3 files changed, 23 insertions(+), 27 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 7008623..c218ab7b 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -8,10 +8,6 @@ extern int do_huge_pmd_anonymous_page(struct mm_struct *mm, extern int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr, struct vm_area_struct *vma); -extern void huge_pmd_set_accessed(struct mm_struct *mm,

• 		  struct vm_area_struct *vma,
  

• 		  unsigned long address, pmd_t *pmd,
  

• 		  pmd_t orig_pmd, int dirty);
  

  extern int do_huge_pmd_wp_page(struct mm_struct *mm, struct

vm_area_struct *vma, unsigned long address, pmd_t *pmd, pmd_t orig_pmd); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index fecbbc5..6c14cb6 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1137,29 +1137,6 @@ out: return ret; }

-void huge_pmd_set_accessed(struct mm_struct *mm,

• 	   struct vm_area_struct *vma,
  

• 	   unsigned long address,
  

• 	   pmd_t *pmd, pmd_t orig_pmd,
  

• 	   int dirty)
  

-{

• spinlock_t *ptl;
• pmd_t entry;
• unsigned long haddr;
• ptl = pmd_lock(mm, pmd);
• if (unlikely(!pmd_same(*pmd, orig_pmd)))

• goto unlock;
  

• entry = pmd_mkyoung(orig_pmd);
• haddr = address & HPAGE_PMD_MASK;
• if (pmdp_set_access_flags(vma, haddr, pmd, entry, dirty))

• update_mmu_cache_pmd(vma, address, pmd);
  

-unlock:

• spin_unlock(ptl);

-}

• static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address,

diff --git a/mm/memory.c b/mm/memory.c index 93897f2..6ced4eb 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3287,6 +3287,29 @@ static int wp_huge_pmd(struct mm_struct *mm, struct vm_area_struct *vma, return VM_FAULT_FALLBACK; }

+static void huge_pmd_set_accessed(struct mm_struct *mm,

• 		  struct vm_area_struct *vma,
  

• 		  unsigned long address,
  

• 		  pmd_t *pmd, pmd_t orig_pmd,
  

• 		  int dirty)
  

+{

• spinlock_t *ptl;
• pmd_t entry;
• unsigned long haddr;
• ptl = pmd_lock(mm, pmd);
• if (unlikely(!pmd_same(*pmd, orig_pmd)))

• goto unlock;
  

• entry = pmd_mkyoung(orig_pmd);
• haddr = address & HPAGE_PMD_MASK;
• if (pmdp_set_access_flags(vma, haddr, pmd, entry, dirty))

• update_mmu_cache_pmd(vma, address, pmd);
  

+unlock:

• spin_unlock(ptl);

+}

• /*
  • These routines also need to handle stuff like marking pages dirty
  • and/or accessed for architectures that don't do it in hardware (most