Commit 67786313 authored by Kefeng Wang's avatar Kefeng Wang
Browse files

mm: use pfn_swap_entry_to_folio() in zap_huge_pmd() 

mainline inclusion
from mainline-v6.9-rc1
commit 0103b27a6b826729dc1500d013e53ebed48980b3
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9CHB4
CVE: NA

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

Call pfn_swap_entry_to_folio() in zap_huge_pmd() as preparation for
converting mm counter functions to take a folio.  Saves a call to
compound_head() embedded inside PageAnon().

Link: https://lkml.kernel.org/r/20240111152429.3374566-7-willy@infradead.org


Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 0103b27a6b826729dc1500d013e53ebed48980b3)
Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
parent f4afee11

mm/huge_memory.c

+10 −7
Original line number Diff line number Diff line
@@ -1870,13 +1870,15 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, 
		zap_deposited_table(tlb->mm, pmd);

		spin_unlock(ptl);

	} else {

		struct page *page = NULL;

		struct folio *folio = NULL;

		int flush_needed = 1;



		if (pmd_present(orig_pmd)) {

			page = pmd_page(orig_pmd);

			struct page *page = pmd_page(orig_pmd);



			folio = page_folio(page);

			add_reliable_page_counter(page, tlb->mm, -HPAGE_PMD_NR);

			folio_remove_rmap_pmd(page_folio(page), page, vma);

			folio_remove_rmap_pmd(folio, page, vma);

			VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);

			VM_BUG_ON_PAGE(!PageHead(page), page);

		} else if (thp_migration_supported()) {
@@ -1884,23 +1886,24 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, 


			VM_BUG_ON(!is_pmd_migration_entry(orig_pmd));

			entry = pmd_to_swp_entry(orig_pmd);

			page = pfn_swap_entry_to_page(entry);

			folio = pfn_swap_entry_folio(entry);

			flush_needed = 0;

		} else

			WARN_ONCE(1, "Non present huge pmd without pmd migration enabled!");



		if (PageAnon(page)) {

		if (folio_test_anon(folio)) {

			zap_deposited_table(tlb->mm, pmd);

			add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);

		} else {

			if (arch_needs_pgtable_deposit())

				zap_deposited_table(tlb->mm, pmd);

			add_mm_counter(tlb->mm, mm_counter_file(page), -HPAGE_PMD_NR);

			add_mm_counter(tlb->mm, mm_counter_file(&folio->page),

				       -HPAGE_PMD_NR);

		}



		spin_unlock(ptl);

		if (flush_needed)

			tlb_remove_page_size(tlb, page, HPAGE_PMD_SIZE);

			tlb_remove_page_size(tlb, &folio->page, HPAGE_PMD_SIZE);

	}

	return 1;

}