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-rw-r--r--mm/huge_memory.c108
1 files changed, 67 insertions, 41 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 33a5dc492810..82166bf974e1 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -130,8 +130,14 @@ static int set_recommended_min_free_kbytes(void)
(unsigned long) nr_free_buffer_pages() / 20);
recommended_min <<= (PAGE_SHIFT-10);
- if (recommended_min > min_free_kbytes)
+ if (recommended_min > min_free_kbytes) {
+ if (user_min_free_kbytes >= 0)
+ pr_info("raising min_free_kbytes from %d to %lu "
+ "to help transparent hugepage allocations\n",
+ min_free_kbytes, recommended_min);
+
min_free_kbytes = recommended_min;
+ }
setup_per_zone_wmarks();
return 0;
}
@@ -655,7 +661,7 @@ out:
hugepage_exit_sysfs(hugepage_kobj);
return err;
}
-module_init(hugepage_init)
+subsys_initcall(hugepage_init);
static int __init setup_transparent_hugepage(char *str)
{
@@ -712,7 +718,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
pgtable_t pgtable;
spinlock_t *ptl;
- VM_BUG_ON(!PageCompound(page));
+ VM_BUG_ON_PAGE(!PageCompound(page), page);
pgtable = pte_alloc_one(mm, haddr);
if (unlikely(!pgtable))
return VM_FAULT_OOM;
@@ -882,6 +888,7 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
ret = 0;
goto out_unlock;
}
+
if (unlikely(pmd_trans_splitting(pmd))) {
/* split huge page running from under us */
spin_unlock(src_ptl);
@@ -892,7 +899,7 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
goto out;
}
src_page = pmd_page(pmd);
- VM_BUG_ON(!PageHead(src_page));
+ VM_BUG_ON_PAGE(!PageHead(src_page), src_page);
get_page(src_page);
page_dup_rmap(src_page);
add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR);
@@ -1066,7 +1073,7 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
ptl = pmd_lock(mm, pmd);
if (unlikely(!pmd_same(*pmd, orig_pmd)))
goto out_free_pages;
- VM_BUG_ON(!PageHead(page));
+ VM_BUG_ON_PAGE(!PageHead(page), page);
pmdp_clear_flush(vma, haddr, pmd);
/* leave pmd empty until pte is filled */
@@ -1132,7 +1139,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
goto out_unlock;
page = pmd_page(orig_pmd);
- VM_BUG_ON(!PageCompound(page) || !PageHead(page));
+ VM_BUG_ON_PAGE(!PageCompound(page) || !PageHead(page), page);
if (page_mapcount(page) == 1) {
pmd_t entry;
entry = pmd_mkyoung(orig_pmd);
@@ -1153,7 +1160,7 @@ alloc:
new_page = NULL;
if (unlikely(!new_page)) {
- if (is_huge_zero_pmd(orig_pmd)) {
+ if (!page) {
ret = do_huge_pmd_wp_zero_page_fallback(mm, vma,
address, pmd, orig_pmd, haddr);
} else {
@@ -1180,7 +1187,7 @@ alloc:
count_vm_event(THP_FAULT_ALLOC);
- if (is_huge_zero_pmd(orig_pmd))
+ if (!page)
clear_huge_page(new_page, haddr, HPAGE_PMD_NR);
else
copy_user_huge_page(new_page, page, haddr, vma, HPAGE_PMD_NR);
@@ -1206,11 +1213,11 @@ alloc:
page_add_new_anon_rmap(new_page, vma, haddr);
set_pmd_at(mm, haddr, pmd, entry);
update_mmu_cache_pmd(vma, address, pmd);
- if (is_huge_zero_pmd(orig_pmd)) {
+ if (!page) {
add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
put_huge_zero_page();
} else {
- VM_BUG_ON(!PageHead(page));
+ VM_BUG_ON_PAGE(!PageHead(page), page);
page_remove_rmap(page);
put_page(page);
}
@@ -1243,8 +1250,12 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
if ((flags & FOLL_DUMP) && is_huge_zero_pmd(*pmd))
return ERR_PTR(-EFAULT);
+ /* Full NUMA hinting faults to serialise migration in fault paths */
+ if ((flags & FOLL_NUMA) && pmd_numa(*pmd))
+ goto out;
+
page = pmd_page(*pmd);
- VM_BUG_ON(!PageHead(page));
+ VM_BUG_ON_PAGE(!PageHead(page), page);
if (flags & FOLL_TOUCH) {
pmd_t _pmd;
/*
@@ -1269,7 +1280,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
}
}
page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT;
- VM_BUG_ON(!PageCompound(page));
+ VM_BUG_ON_PAGE(!PageCompound(page), page);
if (flags & FOLL_GET)
get_page_foll(page);
@@ -1295,6 +1306,17 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
if (unlikely(!pmd_same(pmd, *pmdp)))
goto out_unlock;
+ /*
+ * If there are potential migrations, wait for completion and retry
+ * without disrupting NUMA hinting information. Do not relock and
+ * check_same as the page may no longer be mapped.
+ */
+ if (unlikely(pmd_trans_migrating(*pmdp))) {
+ spin_unlock(ptl);
+ wait_migrate_huge_page(vma->anon_vma, pmdp);
+ goto out;
+ }
+
page = pmd_page(pmd);
BUG_ON(is_huge_zero_page(page));
page_nid = page_to_nid(page);
@@ -1323,23 +1345,22 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
/* If the page was locked, there are no parallel migrations */
if (page_locked)
goto clear_pmdnuma;
+ }
- /*
- * Otherwise wait for potential migrations and retry. We do
- * relock and check_same as the page may no longer be mapped.
- * As the fault is being retried, do not account for it.
- */
+ /* Migration could have started since the pmd_trans_migrating check */
+ if (!page_locked) {
spin_unlock(ptl);
wait_on_page_locked(page);
page_nid = -1;
goto out;
}
- /* Page is misplaced, serialise migrations and parallel THP splits */
+ /*
+ * Page is misplaced. Page lock serialises migrations. Acquire anon_vma
+ * to serialises splits
+ */
get_page(page);
spin_unlock(ptl);
- if (!page_locked)
- lock_page(page);
anon_vma = page_lock_anon_vma_read(page);
/* Confirm the PMD did not change while page_table_lock was released */
@@ -1351,6 +1372,13 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
goto out_unlock;
}
+ /* Bail if we fail to protect against THP splits for any reason */
+ if (unlikely(!anon_vma)) {
+ put_page(page);
+ page_nid = -1;
+ goto clear_pmdnuma;
+ }
+
/*
* Migrate the THP to the requested node, returns with page unlocked
* and pmd_numa cleared.
@@ -1410,9 +1438,9 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
} else {
page = pmd_page(orig_pmd);
page_remove_rmap(page);
- VM_BUG_ON(page_mapcount(page) < 0);
+ VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);
add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
- VM_BUG_ON(!PageHead(page));
+ VM_BUG_ON_PAGE(!PageHead(page), page);
atomic_long_dec(&tlb->mm->nr_ptes);
spin_unlock(ptl);
tlb_remove_page(tlb, page);
@@ -1480,19 +1508,15 @@ int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING);
pmd = pmdp_get_and_clear(mm, old_addr, old_pmd);
VM_BUG_ON(!pmd_none(*new_pmd));
- set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd));
- if (new_ptl != old_ptl) {
- pgtable_t pgtable;
- /*
- * Move preallocated PTE page table if new_pmd is on
- * different PMD page table.
- */
+ if (pmd_move_must_withdraw(new_ptl, old_ptl)) {
+ pgtable_t pgtable;
pgtable = pgtable_trans_huge_withdraw(mm, old_pmd);
pgtable_trans_huge_deposit(mm, new_pmd, pgtable);
-
- spin_unlock(new_ptl);
}
+ set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd));
+ if (new_ptl != old_ptl)
+ spin_unlock(new_ptl);
spin_unlock(old_ptl);
}
out:
@@ -1517,6 +1541,8 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
ret = 1;
if (!prot_numa) {
entry = pmdp_get_and_clear(mm, addr, pmd);
+ if (pmd_numa(entry))
+ entry = pmd_mknonnuma(entry);
entry = pmd_modify(entry, newprot);
ret = HPAGE_PMD_NR;
BUG_ON(pmd_write(entry));
@@ -1531,7 +1557,7 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
*/
if (!is_huge_zero_page(page) &&
!pmd_numa(*pmd)) {
- entry = pmdp_get_and_clear(mm, addr, pmd);
+ entry = *pmd;
entry = pmd_mknuma(entry);
ret = HPAGE_PMD_NR;
}
@@ -2152,9 +2178,9 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
if (unlikely(!page))
goto out;
- VM_BUG_ON(PageCompound(page));
- BUG_ON(!PageAnon(page));
- VM_BUG_ON(!PageSwapBacked(page));
+ VM_BUG_ON_PAGE(PageCompound(page), page);
+ VM_BUG_ON_PAGE(!PageAnon(page), page);
+ VM_BUG_ON_PAGE(!PageSwapBacked(page), page);
/* cannot use mapcount: can't collapse if there's a gup pin */
if (page_count(page) != 1)
@@ -2177,8 +2203,8 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
}
/* 0 stands for page_is_file_cache(page) == false */
inc_zone_page_state(page, NR_ISOLATED_ANON + 0);
- VM_BUG_ON(!PageLocked(page));
- VM_BUG_ON(PageLRU(page));
+ VM_BUG_ON_PAGE(!PageLocked(page), page);
+ VM_BUG_ON_PAGE(PageLRU(page), page);
/* If there is no mapped pte young don't collapse the page */
if (pte_young(pteval) || PageReferenced(page) ||
@@ -2208,7 +2234,7 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page,
} else {
src_page = pte_page(pteval);
copy_user_highpage(page, src_page, address, vma);
- VM_BUG_ON(page_mapcount(src_page) != 1);
+ VM_BUG_ON_PAGE(page_mapcount(src_page) != 1, src_page);
release_pte_page(src_page);
/*
* ptl mostly unnecessary, but preempt has to
@@ -2287,7 +2313,7 @@ static struct page
struct vm_area_struct *vma, unsigned long address,
int node)
{
- VM_BUG_ON(*hpage);
+ VM_BUG_ON_PAGE(*hpage, *hpage);
/*
* Allocate the page while the vma is still valid and under
* the mmap_sem read mode so there is no memory allocation
@@ -2556,7 +2582,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
*/
node = page_to_nid(page);
khugepaged_node_load[node]++;
- VM_BUG_ON(PageCompound(page));
+ VM_BUG_ON_PAGE(PageCompound(page), page);
if (!PageLRU(page) || PageLocked(page) || !PageAnon(page))
goto out_unmap;
/* cannot use mapcount: can't collapse if there's a gup pin */
@@ -2852,7 +2878,7 @@ again:
return;
}
page = pmd_page(*pmd);
- VM_BUG_ON(!page_count(page));
+ VM_BUG_ON_PAGE(!page_count(page), page);
get_page(page);
spin_unlock(ptl);
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.