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-rw-r--r--mm/migrate.c145
1 files changed, 69 insertions, 76 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 99250aee1ac1..738f1d5f8350 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -40,6 +40,7 @@
#include <linux/mmu_notifier.h>
#include <linux/page_idle.h>
#include <linux/page_owner.h>
+#include <linux/sched/mm.h>
#include <asm/tlbflush.h>
@@ -74,7 +75,7 @@ int migrate_prep_local(void)
return 0;
}
-bool isolate_movable_page(struct page *page, isolate_mode_t mode)
+int isolate_movable_page(struct page *page, isolate_mode_t mode)
{
struct address_space *mapping;
@@ -125,14 +126,14 @@ bool isolate_movable_page(struct page *page, isolate_mode_t mode)
__SetPageIsolated(page);
unlock_page(page);
- return true;
+ return 0;
out_no_isolated:
unlock_page(page);
out_putpage:
put_page(page);
out:
- return false;
+ return -EBUSY;
}
/* It should be called on page which is PG_movable */
@@ -168,8 +169,6 @@ void putback_movable_pages(struct list_head *l)
continue;
}
list_del(&page->lru);
- dec_node_page_state(page, NR_ISOLATED_ANON +
- page_is_file_cache(page));
/*
* We isolated non-lru movable page so here we can use
* __PageMovable because LRU page's mapping cannot have
@@ -185,6 +184,8 @@ void putback_movable_pages(struct list_head *l)
unlock_page(page);
put_page(page);
} else {
+ dec_node_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
putback_lru_page(page);
}
}
@@ -193,82 +194,65 @@ void putback_movable_pages(struct list_head *l)
/*
* Restore a potential migration pte to a working pte entry
*/
-static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
+static int remove_migration_pte(struct page *page, struct vm_area_struct *vma,
unsigned long addr, void *old)
{
- struct mm_struct *mm = vma->vm_mm;
+ struct page_vma_mapped_walk pvmw = {
+ .page = old,
+ .vma = vma,
+ .address = addr,
+ .flags = PVMW_SYNC | PVMW_MIGRATION,
+ };
+ struct page *new;
+ pte_t pte;
swp_entry_t entry;
- pmd_t *pmd;
- pte_t *ptep, pte;
- spinlock_t *ptl;
- if (unlikely(PageHuge(new))) {
- ptep = huge_pte_offset(mm, addr);
- if (!ptep)
- goto out;
- ptl = huge_pte_lockptr(hstate_vma(vma), mm, ptep);
- } else {
- pmd = mm_find_pmd(mm, addr);
- if (!pmd)
- goto out;
+ VM_BUG_ON_PAGE(PageTail(page), page);
+ while (page_vma_mapped_walk(&pvmw)) {
+ if (PageKsm(page))
+ new = page;
+ else
+ new = page - pvmw.page->index +
+ linear_page_index(vma, pvmw.address);
- ptep = pte_offset_map(pmd, addr);
+ get_page(new);
+ pte = pte_mkold(mk_pte(new, READ_ONCE(vma->vm_page_prot)));
+ if (pte_swp_soft_dirty(*pvmw.pte))
+ pte = pte_mksoft_dirty(pte);
/*
- * Peek to check is_swap_pte() before taking ptlock? No, we
- * can race mremap's move_ptes(), which skips anon_vma lock.
+ * Recheck VMA as permissions can change since migration started
*/
-
- ptl = pte_lockptr(mm, pmd);
- }
-
- spin_lock(ptl);
- pte = *ptep;
- if (!is_swap_pte(pte))
- goto unlock;
-
- entry = pte_to_swp_entry(pte);
-
- if (!is_migration_entry(entry) ||
- migration_entry_to_page(entry) != old)
- goto unlock;
-
- get_page(new);
- pte = pte_mkold(mk_pte(new, READ_ONCE(vma->vm_page_prot)));
- if (pte_swp_soft_dirty(*ptep))
- pte = pte_mksoft_dirty(pte);
-
- /* Recheck VMA as permissions can change since migration started */
- if (is_write_migration_entry(entry))
- pte = maybe_mkwrite(pte, vma);
+ entry = pte_to_swp_entry(*pvmw.pte);
+ if (is_write_migration_entry(entry))
+ pte = maybe_mkwrite(pte, vma);
#ifdef CONFIG_HUGETLB_PAGE
- if (PageHuge(new)) {
- pte = pte_mkhuge(pte);
- pte = arch_make_huge_pte(pte, vma, new, 0);
- }
+ if (PageHuge(new)) {
+ pte = pte_mkhuge(pte);
+ pte = arch_make_huge_pte(pte, vma, new, 0);
+ }
#endif
- flush_dcache_page(new);
- set_pte_at(mm, addr, ptep, pte);
+ flush_dcache_page(new);
+ set_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte);
- if (PageHuge(new)) {
- if (PageAnon(new))
- hugepage_add_anon_rmap(new, vma, addr);
+ if (PageHuge(new)) {
+ if (PageAnon(new))
+ hugepage_add_anon_rmap(new, vma, pvmw.address);
+ else
+ page_dup_rmap(new, true);
+ } else if (PageAnon(new))
+ page_add_anon_rmap(new, vma, pvmw.address, false);
else
- page_dup_rmap(new, true);
- } else if (PageAnon(new))
- page_add_anon_rmap(new, vma, addr, false);
- else
- page_add_file_rmap(new, false);
+ page_add_file_rmap(new, false);
- if (vma->vm_flags & VM_LOCKED && !PageTransCompound(new))
- mlock_vma_page(new);
+ if (vma->vm_flags & VM_LOCKED && !PageTransCompound(new))
+ mlock_vma_page(new);
+
+ /* No need to invalidate - it was non-present before */
+ update_mmu_cache(vma, pvmw.address, pvmw.pte);
+ }
- /* No need to invalidate - it was non-present before */
- update_mmu_cache(vma, addr, ptep);
-unlock:
- pte_unmap_unlock(ptep, ptl);
-out:
return SWAP_AGAIN;
}
@@ -466,13 +450,15 @@ int migrate_page_move_mapping(struct address_space *mapping,
*/
newpage->index = page->index;
newpage->mapping = page->mapping;
- if (PageSwapBacked(page))
- __SetPageSwapBacked(newpage);
-
get_page(newpage); /* add cache reference */
- if (PageSwapCache(page)) {
- SetPageSwapCache(newpage);
- set_page_private(newpage, page_private(page));
+ if (PageSwapBacked(page)) {
+ __SetPageSwapBacked(newpage);
+ if (PageSwapCache(page)) {
+ SetPageSwapCache(newpage);
+ set_page_private(newpage, page_private(page));
+ }
+ } else {
+ VM_BUG_ON_PAGE(PageSwapCache(page), page);
}
/* Move dirty while page refs frozen and newpage not yet exposed */
@@ -482,7 +468,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
SetPageDirty(newpage);
}
- radix_tree_replace_slot(pslot, newpage);
+ radix_tree_replace_slot(&mapping->page_tree, pslot, newpage);
/*
* Drop cache reference from old page by unfreezing
@@ -556,7 +542,7 @@ int migrate_huge_page_move_mapping(struct address_space *mapping,
get_page(newpage);
- radix_tree_replace_slot(pslot, newpage);
+ radix_tree_replace_slot(&mapping->page_tree, pslot, newpage);
page_ref_unfreeze(page, expected_count - 1);
@@ -1121,8 +1107,15 @@ out:
* restored.
*/
list_del(&page->lru);
- dec_node_page_state(page, NR_ISOLATED_ANON +
- page_is_file_cache(page));
+
+ /*
+ * Compaction can migrate also non-LRU pages which are
+ * not accounted to NR_ISOLATED_*. They can be recognized
+ * as __PageMovable
+ */
+ if (likely(!__PageMovable(page)))
+ dec_node_page_state(page, NR_ISOLATED_ANON +
+ page_is_file_cache(page));
}
/*
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-11 11:14:26 +0000