Commit 06ecf5ab authored by Lance Yang's avatar Lance Yang Committed by Liu Shixin
Browse files

mm/arm64: override clear_young_dirty_ptes() batch helper 

mainline inclusion
from mainline-v6.10-rc1
commit 89e86854fb0aa6e20c0f3d88285fa9cedef4f4e0
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/IAIHQO

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=89e86854fb0aa6e20c0f3d88285fa9cedef4f4e0

--------------------------------

The per-pte get_and_clear/modify/set approach would result in
unfolding/refolding for contpte mappings on arm64.  So we need to override
clear_young_dirty_ptes() for arm64 to avoid it.

Link: https://lkml.kernel.org/r/20240418134435.6092-3-ioworker0@gmail.com


Signed-off-by: default avatarLance Yang <ioworker0@gmail.com>
Suggested-by: default avatarBarry Song <21cnbao@gmail.com>
Suggested-by: default avatarRyan Roberts <ryan.roberts@arm.com>
Reviewed-by: default avatarRyan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jeff Xie <xiehuan09@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLiu Shixin <liushixin2@huawei.com>
parent be9bd9b5

arch/arm64/include/asm/pgtable.h

+55 −0
Original line number Diff line number Diff line
@@ -1036,6 +1036,46 @@ static inline void __wrprotect_ptes(struct mm_struct *mm, unsigned long address, 
		__ptep_set_wrprotect(mm, address, ptep);

}



static inline void __clear_young_dirty_pte(struct vm_area_struct *vma,

					   unsigned long addr, pte_t *ptep,

					   pte_t pte, cydp_t flags)

{

	pte_t old_pte;



	do {

		old_pte = pte;



		if (flags & CYDP_CLEAR_YOUNG)

			pte = pte_mkold(pte);

		if (flags & CYDP_CLEAR_DIRTY)

			pte = pte_mkclean(pte);



		pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),

					       pte_val(old_pte), pte_val(pte));

	} while (pte_val(pte) != pte_val(old_pte));

}



static inline void __clear_young_dirty_ptes(struct vm_area_struct *vma,

					    unsigned long addr, pte_t *ptep,

					    unsigned int nr, cydp_t flags)

{

	pte_t pte;



	for (;;) {

		pte = __ptep_get(ptep);



		if (flags == (CYDP_CLEAR_YOUNG | CYDP_CLEAR_DIRTY))

			__set_pte(ptep, pte_mkclean(pte_mkold(pte)));

		else

			__clear_young_dirty_pte(vma, addr, ptep, pte, flags);



		if (--nr == 0)

			break;

		ptep++;

		addr += PAGE_SIZE;

	}

}



#ifdef CONFIG_TRANSPARENT_HUGEPAGE

#define __HAVE_ARCH_PMDP_SET_WRPROTECT

static inline void pmdp_set_wrprotect(struct mm_struct *mm,
@@ -1204,6 +1244,9 @@ extern void contpte_wrprotect_ptes(struct mm_struct *mm, unsigned long addr, 
extern int contpte_ptep_set_access_flags(struct vm_area_struct *vma,

				unsigned long addr, pte_t *ptep,

				pte_t entry, int dirty);

extern void contpte_clear_young_dirty_ptes(struct vm_area_struct *vma,

				unsigned long addr, pte_t *ptep,

				unsigned int nr, cydp_t flags);



static __always_inline void contpte_try_fold(struct mm_struct *mm,

				unsigned long addr, pte_t *ptep, pte_t pte)
@@ -1428,6 +1471,17 @@ static inline int ptep_set_access_flags(struct vm_area_struct *vma, 
	return contpte_ptep_set_access_flags(vma, addr, ptep, entry, dirty);

}



#define clear_young_dirty_ptes clear_young_dirty_ptes

static inline void clear_young_dirty_ptes(struct vm_area_struct *vma,

					  unsigned long addr, pte_t *ptep,

					  unsigned int nr, cydp_t flags)

{

	if (likely(nr == 1 && !pte_cont(__ptep_get(ptep))))

		__clear_young_dirty_ptes(vma, addr, ptep, nr, flags);

	else

		contpte_clear_young_dirty_ptes(vma, addr, ptep, nr, flags);

}



#else /* CONFIG_ARM64_CONTPTE */



#define ptep_get				__ptep_get
@@ -1447,6 +1501,7 @@ static inline int ptep_set_access_flags(struct vm_area_struct *vma, 
#define wrprotect_ptes				__wrprotect_ptes

#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS

#define ptep_set_access_flags			__ptep_set_access_flags

#define clear_young_dirty_ptes			__clear_young_dirty_ptes



#endif /* CONFIG_ARM64_CONTPTE */

arch/arm64/mm/contpte.c

+29 −0
Original line number Diff line number Diff line
@@ -361,6 +361,35 @@ void contpte_wrprotect_ptes(struct mm_struct *mm, unsigned long addr, 
}

EXPORT_SYMBOL_GPL(contpte_wrprotect_ptes);



void contpte_clear_young_dirty_ptes(struct vm_area_struct *vma,

				    unsigned long addr, pte_t *ptep,

				    unsigned int nr, cydp_t flags)

{

	/*

	 * We can safely clear access/dirty without needing to unfold from

	 * the architectures perspective, even when contpte is set. If the

	 * range starts or ends midway through a contpte block, we can just

	 * expand to include the full contpte block. While this is not

	 * exactly what the core-mm asked for, it tracks access/dirty per

	 * folio, not per page. And since we only create a contpte block

	 * when it is covered by a single folio, we can get away with

	 * clearing access/dirty for the whole block.

	 */

	unsigned long start = addr;

	unsigned long end = start + nr;



	if (pte_cont(__ptep_get(ptep + nr - 1)))

		end = ALIGN(end, CONT_PTE_SIZE);



	if (pte_cont(__ptep_get(ptep))) {

		start = ALIGN_DOWN(start, CONT_PTE_SIZE);

		ptep = contpte_align_down(ptep);

	}



	__clear_young_dirty_ptes(vma, start, ptep, end - start, flags);

}

EXPORT_SYMBOL_GPL(contpte_clear_young_dirty_ptes);



int contpte_ptep_set_access_flags(struct vm_area_struct *vma,

					unsigned long addr, pte_t *ptep,

					pte_t entry, int dirty)