mm: factor out common parts between MADV_COLD and MADV_PAGEOUT

There are many common parts between MADV_COLD and MADV_PAGEOUT.
This patch factor them out to save code duplication.

Link: http://lkml.kernel.org/r/20190726023435.214162-6-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: kbuild test robot <lkp@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/madvise.c b/mm/madvise.c
index 54c5639774b6630b40d171b9504288ec0d132808..2be9f3fdb05e7e9695f444bf18a7306109a0e5bd 100644 (file)
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -32,6 +32,11 @@
 
 #include "internal.h"
 
+struct madvise_walk_private {
+       struct mmu_gather *tlb;
+       bool pageout;
+};
+
 /*
  * Any behaviour which results in changes to the vma->vm_flags needs to
  * take mmap_sem for writing. Others, which simply traverse vmas, need
@@ -292,15 +297,22 @@ static long madvise_willneed(struct vm_area_struct *vma,
        return 0;
 }
 
-static int madvise_cold_pte_range(pmd_t *pmd, unsigned long addr,
-                               unsigned long end, struct mm_walk *walk)
+static int madvise_cold_or_pageout_pte_range(pmd_t *pmd,
+                               unsigned long addr, unsigned long end,
+                               struct mm_walk *walk)
 {
-       struct mmu_gather *tlb = walk->private;
+       struct madvise_walk_private *private = walk->private;
+       struct mmu_gather *tlb = private->tlb;
+       bool pageout = private->pageout;
        struct mm_struct *mm = tlb->mm;
        struct vm_area_struct *vma = walk->vma;
        pte_t *orig_pte, *pte, ptent;
        spinlock_t *ptl;
-       struct page *page;
+       struct page *page = NULL;
+       LIST_HEAD(page_list);
+
+       if (fatal_signal_pending(current))
+               return -EINTR;
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
        if (pmd_trans_huge(*pmd)) {
@@ -348,10 +360,17 @@ static int madvise_cold_pte_range(pmd_t *pmd, unsigned long addr,
                        tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
                }
 
+               ClearPageReferenced(page);
                test_and_clear_page_young(page);
-               deactivate_page(page);
+               if (pageout) {
+                       if (!isolate_lru_page(page))
+                               list_add(&page->lru, &page_list);
+               } else
+                       deactivate_page(page);
 huge_unlock:
                spin_unlock(ptl);
+               if (pageout)
+                       reclaim_pages(&page_list);
                return 0;
        }
 
@@ -419,27 +438,39 @@ regular_page:
                 * As a side effect, it makes confuse idle-page tracking
                 * because they will miss recent referenced history.
                 */
+               ClearPageReferenced(page);
                test_and_clear_page_young(page);
-               deactivate_page(page);
+               if (pageout) {
+                       if (!isolate_lru_page(page))
+                               list_add(&page->lru, &page_list);
+               } else
+                       deactivate_page(page);
        }
 
        arch_leave_lazy_mmu_mode();
        pte_unmap_unlock(orig_pte, ptl);
+       if (pageout)
+               reclaim_pages(&page_list);
        cond_resched();
 
        return 0;
 }
 
 static const struct mm_walk_ops cold_walk_ops = {
-       .pmd_entry = madvise_cold_pte_range,
+       .pmd_entry = madvise_cold_or_pageout_pte_range,
 };
 
 static void madvise_cold_page_range(struct mmu_gather *tlb,
                             struct vm_area_struct *vma,
                             unsigned long addr, unsigned long end)
 {
+       struct madvise_walk_private walk_private = {
+               .pageout = false,
+               .tlb = tlb,
+       };
+
        tlb_start_vma(tlb, vma);
-       walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, NULL);
+       walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private);
        tlb_end_vma(tlb, vma);
 }
 
@@ -462,150 +493,17 @@ static long madvise_cold(struct vm_area_struct *vma,
        return 0;
 }
 
-static int madvise_pageout_pte_range(pmd_t *pmd, unsigned long addr,
-                               unsigned long end, struct mm_walk *walk)
-{
-       struct mmu_gather *tlb = walk->private;
-       struct mm_struct *mm = tlb->mm;
-       struct vm_area_struct *vma = walk->vma;
-       pte_t *orig_pte, *pte, ptent;
-       spinlock_t *ptl;
-       LIST_HEAD(page_list);
-       struct page *page;
-
-       if (fatal_signal_pending(current))
-               return -EINTR;
-
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-       if (pmd_trans_huge(*pmd)) {
-               pmd_t orig_pmd;
-               unsigned long next = pmd_addr_end(addr, end);
-
-               tlb_change_page_size(tlb, HPAGE_PMD_SIZE);
-               ptl = pmd_trans_huge_lock(pmd, vma);
-               if (!ptl)
-                       return 0;
-
-               orig_pmd = *pmd;
-               if (is_huge_zero_pmd(orig_pmd))
-                       goto huge_unlock;
-
-               if (unlikely(!pmd_present(orig_pmd))) {
-                       VM_BUG_ON(thp_migration_supported() &&
-                                       !is_pmd_migration_entry(orig_pmd));
-                       goto huge_unlock;
-               }
-
-               page = pmd_page(orig_pmd);
-               if (next - addr != HPAGE_PMD_SIZE) {
-                       int err;
-
-                       if (page_mapcount(page) != 1)
-                               goto huge_unlock;
-                       get_page(page);
-                       spin_unlock(ptl);
-                       lock_page(page);
-                       err = split_huge_page(page);
-                       unlock_page(page);
-                       put_page(page);
-                       if (!err)
-                               goto regular_page;
-                       return 0;
-               }
-
-               if (pmd_young(orig_pmd)) {
-                       pmdp_invalidate(vma, addr, pmd);
-                       orig_pmd = pmd_mkold(orig_pmd);
-
-                       set_pmd_at(mm, addr, pmd, orig_pmd);
-                       tlb_remove_tlb_entry(tlb, pmd, addr);
-               }
-
-               ClearPageReferenced(page);
-               test_and_clear_page_young(page);
-
-               if (!isolate_lru_page(page))
-                       list_add(&page->lru, &page_list);
-huge_unlock:
-               spin_unlock(ptl);
-               reclaim_pages(&page_list);
-               return 0;
-       }
-
-       if (pmd_trans_unstable(pmd))
-               return 0;
-regular_page:
-#endif
-       tlb_change_page_size(tlb, PAGE_SIZE);
-       orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
-       flush_tlb_batched_pending(mm);
-       arch_enter_lazy_mmu_mode();
-       for (; addr < end; pte++, addr += PAGE_SIZE) {
-               ptent = *pte;
-               if (!pte_present(ptent))
-                       continue;
-
-               page = vm_normal_page(vma, addr, ptent);
-               if (!page)
-                       continue;
-
-               /*
-                * creating a THP page is expensive so split it only if we
-                * are sure it's worth. Split it if we are only owner.
-                */
-               if (PageTransCompound(page)) {
-                       if (page_mapcount(page) != 1)
-                               break;
-                       get_page(page);
-                       if (!trylock_page(page)) {
-                               put_page(page);
-                               break;
-                       }
-                       pte_unmap_unlock(orig_pte, ptl);
-                       if (split_huge_page(page)) {
-                               unlock_page(page);
-                               put_page(page);
-                               pte_offset_map_lock(mm, pmd, addr, &ptl);
-                               break;
-                       }
-                       unlock_page(page);
-                       put_page(page);
-                       pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
-                       pte--;
-                       addr -= PAGE_SIZE;
-                       continue;
-               }
-
-               VM_BUG_ON_PAGE(PageTransCompound(page), page);
-
-               if (pte_young(ptent)) {
-                       ptent = ptep_get_and_clear_full(mm, addr, pte,
-                                                       tlb->fullmm);
-                       ptent = pte_mkold(ptent);
-                       set_pte_at(mm, addr, pte, ptent);
-                       tlb_remove_tlb_entry(tlb, pte, addr);
-               }
-               ClearPageReferenced(page);
-               test_and_clear_page_young(page);
-
-               if (!isolate_lru_page(page))
-                       list_add(&page->lru, &page_list);
-       }
-
-       arch_leave_lazy_mmu_mode();
-       pte_unmap_unlock(orig_pte, ptl);
-       reclaim_pages(&page_list);
-       cond_resched();
-
-       return 0;
-}
-
 static void madvise_pageout_page_range(struct mmu_gather *tlb,
                             struct vm_area_struct *vma,
                             unsigned long addr, unsigned long end)
 {
+       struct madvise_walk_private walk_private = {
+               .pageout = true,
+               .tlb = tlb,
+       };
+
        tlb_start_vma(tlb, vma);
-       walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, NULL);
+       walk_page_range(vma->vm_mm, addr, end, &cold_walk_ops, &walk_private);
        tlb_end_vma(tlb, vma);
 }