Commit 8018db85 authored by Peter Xu's avatar Peter Xu Committed by Linus Torvalds
Browse files

mm: rework swap handling of zap_pte_range 

Clean the code up by merging the device private/exclusive swap entry
handling with the rest, then we merge the pte clear operation too.

struct* page is defined in multiple places in the function, move it
upward.

free_swap_and_cache() is only useful for !non_swap_entry() case, put it
into the condition.

No functional change intended.

Link: https://lkml.kernel.org/r/20220216094810.60572-5-peterx@redhat.com


Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Reviewed-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Alistair Popple <apopple@nvidia.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 2e148f1e

mm/memory.c

+6 −15
Original line number Original line Diff line number Diff line
@@ -1361,6 +1361,8 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, 
	arch_enter_lazy_mmu_mode();

	arch_enter_lazy_mmu_mode();

	do {

	do {

		pte_t ptent = *pte;

		pte_t ptent = *pte;

		struct page *page;



		if (pte_none(ptent))

		if (pte_none(ptent))

			continue;

			continue;
@@ -1368,8 +1370,6 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, 
			break;

			break;





		if (pte_present(ptent)) {

		if (pte_present(ptent)) {

			struct page *page;



			page = vm_normal_page(vma, addr, ptent);

			page = vm_normal_page(vma, addr, ptent);

			if (unlikely(!should_zap_page(details, page)))

			if (unlikely(!should_zap_page(details, page)))

				continue;

				continue;
@@ -1403,28 +1403,21 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, 
		entry = pte_to_swp_entry(ptent);

		entry = pte_to_swp_entry(ptent);

		if (is_device_private_entry(entry) ||

		if (is_device_private_entry(entry) ||

		    is_device_exclusive_entry(entry)) {

		    is_device_exclusive_entry(entry)) {

			struct page *page = pfn_swap_entry_to_page(entry);

			page = pfn_swap_entry_to_page(entry);



			if (unlikely(!should_zap_page(details, page)))

			if (unlikely(!should_zap_page(details, page)))

				continue;

				continue;

			pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);

			rss[mm_counter(page)]--;

			rss[mm_counter(page)]--;



			if (is_device_private_entry(entry))

			if (is_device_private_entry(entry))

				page_remove_rmap(page, false);

				page_remove_rmap(page, false);



			put_page(page);

			put_page(page);

			continue;

		} else if (!non_swap_entry(entry)) {

		}



		if (!non_swap_entry(entry)) {

			/* Genuine swap entry, hence a private anon page */

			/* Genuine swap entry, hence a private anon page */

			if (!should_zap_cows(details))

			if (!should_zap_cows(details))

				continue;

				continue;

			rss[MM_SWAPENTS]--;

			rss[MM_SWAPENTS]--;

			if (unlikely(!free_swap_and_cache(entry)))

				print_bad_pte(vma, addr, ptent, NULL);

		} else if (is_migration_entry(entry)) {

		} else if (is_migration_entry(entry)) {

			struct page *page;



			page = pfn_swap_entry_to_page(entry);

			page = pfn_swap_entry_to_page(entry);

			if (!should_zap_page(details, page))

			if (!should_zap_page(details, page))

				continue;

				continue;
@@ -1436,8 +1429,6 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, 
			/* We should have covered all the swap entry types */

			/* We should have covered all the swap entry types */

			WARN_ON_ONCE(1);

			WARN_ON_ONCE(1);

		}

		}

		if (unlikely(!free_swap_and_cache(entry)))

			print_bad_pte(vma, addr, ptent, NULL);

		pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);

		pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);

	} while (pte++, addr += PAGE_SIZE, addr != end);

	} while (pte++, addr += PAGE_SIZE, addr != end);