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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2017-02-25 01:58:01 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-25 04:46:55 +0300
commitc7ab0d2fdc840266b39db94538f74207ec2afbf6 (patch)
tree668097f8e471bdece447f2c334244c4b5e98081e /mm/rmap.c
parentf27176cfc363d395eea8dc5c4a26e5d6d7d65eaf (diff)
downloadlinux-c7ab0d2fdc840266b39db94538f74207ec2afbf6.tar.xz
mm: convert try_to_unmap_one() to use page_vma_mapped_walk()
For consistency, it worth converting all page_check_address() to page_vma_mapped_walk(), so we could drop the former. It also makes freeze_page() as we walk though rmap only once. Link: http://lkml.kernel.org/r/20170129173858.45174-8-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c260
1 files changed, 133 insertions, 127 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 58597de049fd..11668fb881d8 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -607,8 +607,7 @@ void try_to_unmap_flush_dirty(void)
try_to_unmap_flush();
}
-static void set_tlb_ubc_flush_pending(struct mm_struct *mm,
- struct page *page, bool writable)
+static void set_tlb_ubc_flush_pending(struct mm_struct *mm, bool writable)
{
struct tlbflush_unmap_batch *tlb_ubc = &current->tlb_ubc;
@@ -643,8 +642,7 @@ static bool should_defer_flush(struct mm_struct *mm, enum ttu_flags flags)
return should_defer;
}
#else
-static void set_tlb_ubc_flush_pending(struct mm_struct *mm,
- struct page *page, bool writable)
+static void set_tlb_ubc_flush_pending(struct mm_struct *mm, bool writable)
{
}
@@ -1459,155 +1457,163 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
unsigned long address, void *arg)
{
struct mm_struct *mm = vma->vm_mm;
- pte_t *pte;
+ struct page_vma_mapped_walk pvmw = {
+ .page = page,
+ .vma = vma,
+ .address = address,
+ };
pte_t pteval;
- spinlock_t *ptl;
+ struct page *subpage;
int ret = SWAP_AGAIN;
struct rmap_private *rp = arg;
enum ttu_flags flags = rp->flags;
/* munlock has nothing to gain from examining un-locked vmas */
if ((flags & TTU_MUNLOCK) && !(vma->vm_flags & VM_LOCKED))
- goto out;
+ return SWAP_AGAIN;
if (flags & TTU_SPLIT_HUGE_PMD) {
split_huge_pmd_address(vma, address,
flags & TTU_MIGRATION, page);
- /* check if we have anything to do after split */
- if (page_mapcount(page) == 0)
- goto out;
}
- pte = page_check_address(page, mm, address, &ptl,
- PageTransCompound(page));
- if (!pte)
- goto out;
+ while (page_vma_mapped_walk(&pvmw)) {
+ subpage = page - page_to_pfn(page) + pte_pfn(*pvmw.pte);
+ address = pvmw.address;
- /*
- * If the page is mlock()d, we cannot swap it out.
- * If it's recently referenced (perhaps page_referenced
- * skipped over this mm) then we should reactivate it.
- */
- if (!(flags & TTU_IGNORE_MLOCK)) {
- if (vma->vm_flags & VM_LOCKED) {
- /* PTE-mapped THP are never mlocked */
- if (!PageTransCompound(page)) {
- /*
- * Holding pte lock, we do *not* need
- * mmap_sem here
- */
- mlock_vma_page(page);
+ /* Unexpected PMD-mapped THP? */
+ VM_BUG_ON_PAGE(!pvmw.pte, page);
+
+ /*
+ * If the page is mlock()d, we cannot swap it out.
+ * If it's recently referenced (perhaps page_referenced
+ * skipped over this mm) then we should reactivate it.
+ */
+ if (!(flags & TTU_IGNORE_MLOCK)) {
+ if (vma->vm_flags & VM_LOCKED) {
+ /* PTE-mapped THP are never mlocked */
+ if (!PageTransCompound(page)) {
+ /*
+ * Holding pte lock, we do *not* need
+ * mmap_sem here
+ */
+ mlock_vma_page(page);
+ }
+ ret = SWAP_MLOCK;
+ page_vma_mapped_walk_done(&pvmw);
+ break;
}
- ret = SWAP_MLOCK;
- goto out_unmap;
+ if (flags & TTU_MUNLOCK)
+ continue;
}
- if (flags & TTU_MUNLOCK)
- goto out_unmap;
- }
- if (!(flags & TTU_IGNORE_ACCESS)) {
- if (ptep_clear_flush_young_notify(vma, address, pte)) {
- ret = SWAP_FAIL;
- goto out_unmap;
+
+ if (!(flags & TTU_IGNORE_ACCESS)) {
+ if (ptep_clear_flush_young_notify(vma, address,
+ pvmw.pte)) {
+ ret = SWAP_FAIL;
+ page_vma_mapped_walk_done(&pvmw);
+ break;
+ }
}
- }
- /* Nuke the page table entry. */
- flush_cache_page(vma, address, page_to_pfn(page));
- if (should_defer_flush(mm, flags)) {
- /*
- * We clear the PTE but do not flush so potentially a remote
- * CPU could still be writing to the page. If the entry was
- * previously clean then the architecture must guarantee that
- * a clear->dirty transition on a cached TLB entry is written
- * through and traps if the PTE is unmapped.
- */
- pteval = ptep_get_and_clear(mm, address, pte);
+ /* Nuke the page table entry. */
+ flush_cache_page(vma, address, pte_pfn(*pvmw.pte));
+ if (should_defer_flush(mm, flags)) {
+ /*
+ * We clear the PTE but do not flush so potentially
+ * a remote CPU could still be writing to the page.
+ * If the entry was previously clean then the
+ * architecture must guarantee that a clear->dirty
+ * transition on a cached TLB entry is written through
+ * and traps if the PTE is unmapped.
+ */
+ pteval = ptep_get_and_clear(mm, address, pvmw.pte);
+
+ set_tlb_ubc_flush_pending(mm, pte_dirty(pteval));
+ } else {
+ pteval = ptep_clear_flush(vma, address, pvmw.pte);
+ }
- set_tlb_ubc_flush_pending(mm, page, pte_dirty(pteval));
- } else {
- pteval = ptep_clear_flush(vma, address, pte);
- }
+ /* Move the dirty bit to the page. Now the pte is gone. */
+ if (pte_dirty(pteval))
+ set_page_dirty(page);
- /* Move the dirty bit to the physical page now the pte is gone. */
- if (pte_dirty(pteval))
- set_page_dirty(page);
+ /* Update high watermark before we lower rss */
+ update_hiwater_rss(mm);
- /* Update high watermark before we lower rss */
- update_hiwater_rss(mm);
+ if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
+ if (PageHuge(page)) {
+ int nr = 1 << compound_order(page);
+ hugetlb_count_sub(nr, mm);
+ } else {
+ dec_mm_counter(mm, mm_counter(page));
+ }
- if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
- if (PageHuge(page)) {
- hugetlb_count_sub(1 << compound_order(page), mm);
- } else {
+ pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
+ set_pte_at(mm, address, pvmw.pte, pteval);
+ } else if (pte_unused(pteval)) {
+ /*
+ * The guest indicated that the page content is of no
+ * interest anymore. Simply discard the pte, vmscan
+ * will take care of the rest.
+ */
dec_mm_counter(mm, mm_counter(page));
- }
- set_pte_at(mm, address, pte,
- swp_entry_to_pte(make_hwpoison_entry(page)));
- } else if (pte_unused(pteval)) {
- /*
- * The guest indicated that the page content is of no
- * interest anymore. Simply discard the pte, vmscan
- * will take care of the rest.
- */
- dec_mm_counter(mm, mm_counter(page));
- } else if (IS_ENABLED(CONFIG_MIGRATION) && (flags & TTU_MIGRATION)) {
- swp_entry_t entry;
- pte_t swp_pte;
- /*
- * Store the pfn of the page in a special migration
- * pte. do_swap_page() will wait until the migration
- * pte is removed and then restart fault handling.
- */
- entry = make_migration_entry(page, pte_write(pteval));
- swp_pte = swp_entry_to_pte(entry);
- if (pte_soft_dirty(pteval))
- swp_pte = pte_swp_mksoft_dirty(swp_pte);
- set_pte_at(mm, address, pte, swp_pte);
- } else if (PageAnon(page)) {
- swp_entry_t entry = { .val = page_private(page) };
- pte_t swp_pte;
- /*
- * Store the swap location in the pte.
- * See handle_pte_fault() ...
- */
- VM_BUG_ON_PAGE(!PageSwapCache(page), page);
+ } else if (IS_ENABLED(CONFIG_MIGRATION) &&
+ (flags & TTU_MIGRATION)) {
+ swp_entry_t entry;
+ pte_t swp_pte;
+ /*
+ * Store the pfn of the page in a special migration
+ * pte. do_swap_page() will wait until the migration
+ * pte is removed and then restart fault handling.
+ */
+ entry = make_migration_entry(subpage,
+ pte_write(pteval));
+ swp_pte = swp_entry_to_pte(entry);
+ if (pte_soft_dirty(pteval))
+ swp_pte = pte_swp_mksoft_dirty(swp_pte);
+ set_pte_at(mm, address, pvmw.pte, swp_pte);
+ } else if (PageAnon(page)) {
+ swp_entry_t entry = { .val = page_private(subpage) };
+ pte_t swp_pte;
+ /*
+ * Store the swap location in the pte.
+ * See handle_pte_fault() ...
+ */
+ VM_BUG_ON_PAGE(!PageSwapCache(page), page);
+
+ if (!PageDirty(page) && (flags & TTU_LZFREE)) {
+ /* It's a freeable page by MADV_FREE */
+ dec_mm_counter(mm, MM_ANONPAGES);
+ rp->lazyfreed++;
+ goto discard;
+ }
- if (!PageDirty(page) && (flags & TTU_LZFREE)) {
- /* It's a freeable page by MADV_FREE */
+ if (swap_duplicate(entry) < 0) {
+ set_pte_at(mm, address, pvmw.pte, pteval);
+ ret = SWAP_FAIL;
+ page_vma_mapped_walk_done(&pvmw);
+ break;
+ }
+ if (list_empty(&mm->mmlist)) {
+ spin_lock(&mmlist_lock);
+ if (list_empty(&mm->mmlist))
+ list_add(&mm->mmlist, &init_mm.mmlist);
+ spin_unlock(&mmlist_lock);
+ }
dec_mm_counter(mm, MM_ANONPAGES);
- rp->lazyfreed++;
- goto discard;
- }
-
- if (swap_duplicate(entry) < 0) {
- set_pte_at(mm, address, pte, pteval);
- ret = SWAP_FAIL;
- goto out_unmap;
- }
- if (list_empty(&mm->mmlist)) {
- spin_lock(&mmlist_lock);
- if (list_empty(&mm->mmlist))
- list_add(&mm->mmlist, &init_mm.mmlist);
- spin_unlock(&mmlist_lock);
- }
- dec_mm_counter(mm, MM_ANONPAGES);
- inc_mm_counter(mm, MM_SWAPENTS);
- swp_pte = swp_entry_to_pte(entry);
- if (pte_soft_dirty(pteval))
- swp_pte = pte_swp_mksoft_dirty(swp_pte);
- set_pte_at(mm, address, pte, swp_pte);
- } else
- dec_mm_counter(mm, mm_counter_file(page));
-
+ inc_mm_counter(mm, MM_SWAPENTS);
+ swp_pte = swp_entry_to_pte(entry);
+ if (pte_soft_dirty(pteval))
+ swp_pte = pte_swp_mksoft_dirty(swp_pte);
+ set_pte_at(mm, address, pvmw.pte, swp_pte);
+ } else
+ dec_mm_counter(mm, mm_counter_file(page));
discard:
- page_remove_rmap(page, PageHuge(page));
- put_page(page);
-
-out_unmap:
- pte_unmap_unlock(pte, ptl);
- if (ret != SWAP_FAIL && ret != SWAP_MLOCK && !(flags & TTU_MUNLOCK))
+ page_remove_rmap(subpage, PageHuge(page));
+ put_page(page);
mmu_notifier_invalidate_page(mm, address);
-out:
+ }
return ret;
}
@@ -1632,7 +1638,7 @@ static bool invalid_migration_vma(struct vm_area_struct *vma, void *arg)
static int page_mapcount_is_zero(struct page *page)
{
- return !page_mapcount(page);
+ return !total_mapcount(page);
}
/**