Commit 03c4f204 authored by Qi Zheng's avatar Qi Zheng Committed by Linus Torvalds
Browse files

mm: introduce pmd_install() helper 

Patch series "Do some code cleanups related to mm", v3.

This patch (of 2):

Currently we have three times the same few lines repeated in the code.
Deduplicate them by newly introduced pmd_install() helper.

Link: https://lkml.kernel.org/r/20210901102722.47686-1-zhengqi.arch@bytedance.com
Link: https://lkml.kernel.org/r/20210901102722.47686-2-zhengqi.arch@bytedance.com


Signed-off-by: default avatarQi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarMuchun Song <songmuchun@bytedance.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Mika Penttila <mika.penttila@nextfour.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 91b61ef3

mm/filemap.c

+2 −9
Original line number Diff line number Diff line
@@ -3211,15 +3211,8 @@ static bool filemap_map_pmd(struct vm_fault *vmf, struct page *page) 
	    }

	}



	if (pmd_none(*vmf->pmd)) {

		vmf->ptl = pmd_lock(mm, vmf->pmd);

		if (likely(pmd_none(*vmf->pmd))) {

			mm_inc_nr_ptes(mm);

			pmd_populate(mm, vmf->pmd, vmf->prealloc_pte);

			vmf->prealloc_pte = NULL;

		}

		spin_unlock(vmf->ptl);

	}

	if (pmd_none(*vmf->pmd))

		pmd_install(mm, vmf->pmd, &vmf->prealloc_pte);



	/* See comment in handle_pte_fault() */

	if (pmd_devmap_trans_unstable(vmf->pmd)) {

mm/internal.h

+1 −0
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf); 


void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,

		unsigned long floor, unsigned long ceiling);

void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte);



static inline bool can_madv_lru_vma(struct vm_area_struct *vma)

{

mm/memory.c

+16 −18
Original line number Diff line number Diff line
@@ -433,9 +433,20 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma, 
	}

}



void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte)

{

	spinlock_t *ptl = pmd_lock(mm, pmd);



	if (likely(pmd_none(*pmd))) {	/* Has another populated it ? */

		mm_inc_nr_ptes(mm);

		pmd_populate(mm, pmd, *pte);

		*pte = NULL;

	}

	spin_unlock(ptl);

}



int __pte_alloc(struct mm_struct *mm, pmd_t *pmd)

{

	spinlock_t *ptl;

	pgtable_t new = pte_alloc_one(mm);

	if (!new)

		return -ENOMEM;
@@ -455,13 +466,7 @@ int __pte_alloc(struct mm_struct *mm, pmd_t *pmd) 
	 */

	smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */



	ptl = pmd_lock(mm, pmd);

	if (likely(pmd_none(*pmd))) {	/* Has another populated it ? */

		mm_inc_nr_ptes(mm);

		pmd_populate(mm, pmd, new);

		new = NULL;

	}

	spin_unlock(ptl);

	pmd_install(mm, pmd, &new);

	if (new)

		pte_free(mm, new);

	return 0;
@@ -4024,18 +4029,11 @@ vm_fault_t finish_fault(struct vm_fault *vmf) 
				return ret;

		}



		if (vmf->prealloc_pte) {

			vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd);

			if (likely(pmd_none(*vmf->pmd))) {

				mm_inc_nr_ptes(vma->vm_mm);

				pmd_populate(vma->vm_mm, vmf->pmd, vmf->prealloc_pte);

				vmf->prealloc_pte = NULL;

			}

			spin_unlock(vmf->ptl);

		} else if (unlikely(pte_alloc(vma->vm_mm, vmf->pmd))) {

		if (vmf->prealloc_pte)

			pmd_install(vma->vm_mm, vmf->pmd, &vmf->prealloc_pte);

		else if (unlikely(pte_alloc(vma->vm_mm, vmf->pmd)))

			return VM_FAULT_OOM;

	}

	}



	/* See comment in handle_pte_fault() */

	if (pmd_devmap_trans_unstable(vmf->pmd))