Commit ac775677 authored by Wei Yang's avatar Wei Yang Committed by Andrew Morton
Browse files

mm/khugepaged: unify pmd folio installation with map_anon_folio_pmd() 

Currently we install pmd folio with map_anon_folio_pmd() in
__do_huge_pmd_anonymous_page() and do_huge_zero_wp_pmd().  While in
collapse_huge_page(), it is done with identical code except statistics
adjustment.

Unify the process with map_anon_folio_pmd() to install pmd folio.  Split
it to map_anon_folio_pmd_pf() and map_anon_folio_pmd_nopf() to be used in
page fault or not respectively.

No functional change is intended.

[akpm@linux-foundation.org: remove unneeded map_anon_folio_pmd_nopf() stub, per Wei & David]
Link: https://lkml.kernel.org/r/20251008095453.18772-3-richard.weiyang@gmail.com


Signed-off-by: default avatarWei Yang <richard.weiyang@gmail.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarZi Yan <ziy@nvidia.com>
Acked-by: default avatarLance Yang <lance.yang@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 2a1351cd

include/linux/huge_mm.h

+2 −0
Original line number Diff line number Diff line
@@ -533,6 +533,8 @@ void split_huge_pmd_locked(struct vm_area_struct *vma, unsigned long address, 
			   pmd_t *pmd, bool freeze);

bool unmap_huge_pmd_locked(struct vm_area_struct *vma, unsigned long addr,

			   pmd_t *pmdp, struct folio *folio);

void map_anon_folio_pmd_nopf(struct folio *folio, pmd_t *pmd,

		struct vm_area_struct *vma, unsigned long haddr);



#else /* CONFIG_TRANSPARENT_HUGEPAGE */

mm/huge_memory.c

+10 −4
Original line number Diff line number Diff line
@@ -1218,7 +1218,7 @@ static struct folio *vma_alloc_anon_folio_pmd(struct vm_area_struct *vma, 
	return folio;

}



static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd,

void map_anon_folio_pmd_nopf(struct folio *folio, pmd_t *pmd,

		struct vm_area_struct *vma, unsigned long haddr)

{

	pmd_t entry;
@@ -1229,11 +1229,17 @@ static void map_anon_folio_pmd(struct folio *folio, pmd_t *pmd, 
	folio_add_lru_vma(folio, vma);

	set_pmd_at(vma->vm_mm, haddr, pmd, entry);

	update_mmu_cache_pmd(vma, haddr, pmd);

	deferred_split_folio(folio, false);

}



static void map_anon_folio_pmd_pf(struct folio *folio, pmd_t *pmd,

		struct vm_area_struct *vma, unsigned long haddr)

{

	map_anon_folio_pmd_nopf(folio, pmd, vma, haddr);

	add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);

	count_vm_event(THP_FAULT_ALLOC);

	count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC);

	count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC);

	deferred_split_folio(folio, false);

}



static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf)
@@ -1272,7 +1278,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf) 
			return ret;

		}

		pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable);

		map_anon_folio_pmd(folio, vmf->pmd, vma, haddr);

		map_anon_folio_pmd_pf(folio, vmf->pmd, vma, haddr);

		mm_inc_nr_ptes(vma->vm_mm);

		spin_unlock(vmf->ptl);

	}
@@ -1944,7 +1950,7 @@ static vm_fault_t do_huge_zero_wp_pmd(struct vm_fault *vmf) 
	if (ret)

		goto release;

	(void)pmdp_huge_clear_flush(vma, haddr, vmf->pmd);

	map_anon_folio_pmd(folio, vmf->pmd, vma, haddr);

	map_anon_folio_pmd_pf(folio, vmf->pmd, vma, haddr);

	goto unlock;

release:

	folio_put(folio);

mm/khugepaged.c

+1 −8
Original line number Diff line number Diff line
@@ -1226,17 +1226,10 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address, 
	__folio_mark_uptodate(folio);

	pgtable = pmd_pgtable(_pmd);



	_pmd = folio_mk_pmd(folio, vma->vm_page_prot);

	_pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma);



	spin_lock(pmd_ptl);

	BUG_ON(!pmd_none(*pmd));

	folio_add_new_anon_rmap(folio, vma, address, RMAP_EXCLUSIVE);

	folio_add_lru_vma(folio, vma);

	pgtable_trans_huge_deposit(mm, pmd, pgtable);

	set_pmd_at(mm, address, pmd, _pmd);

	update_mmu_cache_pmd(vma, address, pmd);

	deferred_split_folio(folio, false);

	map_anon_folio_pmd_nopf(folio, pmd, vma, address);

	spin_unlock(pmd_ptl);



	folio = NULL;