return -ENOMEM;
/* __khugepaged_exit() must not run from under us */
- VM_BUG_ON_MM(atomic_read(&mm->mm_users) == 0, mm);
+ VM_BUG_ON_MM(khugepaged_test_exit(mm), mm);
if (unlikely(test_and_set_bit(MMF_VM_HUGEPAGE, &mm->flags))) {
free_mm_slot(mm_slot);
return 0;
*
* The page table that maps the page has been already unlinked
* from the page table tree and this process cannot get
- * an additinal pin on the page.
+ * an additional pin on the page.
*
* New pins can come later if the page is shared across fork,
* but not from this process. The other process cannot write to
if (pte_write(pteval))
writable = true;
}
- if (likely(writable)) {
- if (likely(referenced)) {
- result = SCAN_SUCCEED;
- trace_mm_collapse_huge_page_isolate(page, none_or_zero,
- referenced, writable, result);
- return 1;
- }
- } else {
+
+ if (unlikely(!writable)) {
result = SCAN_PAGE_RO;
+ } else if (unlikely(!referenced)) {
+ result = SCAN_LACK_REFERENCED_PAGE;
+ } else {
+ result = SCAN_SUCCEED;
+ trace_mm_collapse_huge_page_isolate(page, none_or_zero,
+ referenced, writable, result);
+ return 1;
}
-
out:
release_pte_pages(pte, _pte, compound_pagelist);
trace_mm_collapse_huge_page_isolate(page, none_or_zero,
* If node_reclaim_mode is disabled, then no extra effort is made to
* allocate memory locally.
*/
- if (!node_reclaim_mode)
+ if (!node_reclaim_enabled())
return false;
/* If there is a count for this node already, it must be acceptable */
mmap_write_lock(mm);
result = hugepage_vma_revalidate(mm, address, &vma);
if (result)
- goto out;
+ goto out_up_write;
/* check if the pmd is still valid */
if (mm_find_pmd(mm, address) != pmd)
- goto out;
+ goto out_up_write;
anon_vma_lock_write(vma->anon_vma);
spin_unlock(pmd_ptl);
anon_vma_unlock_write(vma->anon_vma);
result = SCAN_FAIL;
- goto out;
+ goto out_up_write;
}
/*
__collapse_huge_page_copy(pte, new_page, vma, address, pte_ptl,
&compound_pagelist);
pte_unmap(pte);
+ /*
+ * spin_lock() below is not the equivalent of smp_wmb(), but
+ * the smp_wmb() inside __SetPageUptodate() can be reused to
+ * avoid the copy_huge_page writes to become visible after
+ * the set_pmd_at() write.
+ */
__SetPageUptodate(new_page);
pgtable = pmd_pgtable(_pmd);
_pmd = mk_huge_pmd(new_page, vma->vm_page_prot);
_pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma);
- /*
- * spin_lock() below is not the equivalent of smp_wmb(), so
- * this is needed to avoid the copy_huge_page writes to become
- * visible after the set_pmd_at() write.
- */
- smp_wmb();
-
spin_lock(pmd_ptl);
BUG_ON(!pmd_none(*pmd));
page_add_new_anon_rmap(new_page, vma, address, true);
mem_cgroup_uncharge(*hpage);
trace_mm_collapse_huge_page(mm, isolated, result);
return;
-out:
- goto out_up_write;
}
static int khugepaged_scan_pmd(struct mm_struct *mm,
goto out_unmap;
}
}
- if (!pte_present(pteval)) {
- result = SCAN_PTE_NON_PRESENT;
- goto out_unmap;
- }
if (pte_uffd_wp(pteval)) {
/*
* Don't collapse the page if any of the small
int i;
if (!vma || !vma->vm_file ||
- vma->vm_start > haddr || vma->vm_end < haddr + HPAGE_PMD_SIZE)
+ !range_in_vma(vma, haddr, haddr + HPAGE_PMD_SIZE))
return;
/*
goto drop_hpage;
}
-static int khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot)
+static void khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot)
{
struct mm_struct *mm = mm_slot->mm;
int i;
if (likely(mm_slot->nr_pte_mapped_thp == 0))
- return 0;
+ return;
if (!mmap_write_trylock(mm))
- return -EBUSY;
+ return;
if (unlikely(khugepaged_test_exit(mm)))
goto out;
out:
mm_slot->nr_pte_mapped_thp = 0;
mmap_write_unlock(mm);
- return 0;
}
static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
BUILD_BUG();
}
-static int khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot)
+static void khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot)
{
- return 0;
}
#endif
{
struct page *hpage = NULL;
unsigned int progress = 0, pass_through_head = 0;
- unsigned int pages = khugepaged_pages_to_scan;
+ unsigned int pages = READ_ONCE(khugepaged_pages_to_scan);
bool wait = true;
- barrier(); /* write khugepaged_pages_to_scan to local stack */
-
lru_add_drain_all();
while (progress < pages) {