Revert "mm, thp: Do not make pmd/pud dirty without a reason"
This reverts commit 152e93af3cfe2d29d8136cc0a02a8612507136ee.
It was a nice cleanup in theory, but as Nicolai Stange points out, we do
need to make the page dirty for the copy-on-write case even when we
didn't end up making it writable, since the dirty bit is what we use to
check that we've gone through a COW cycle.
Reported-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f22401f..0e7ded9 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -474,13 +474,10 @@
}
__setup("transparent_hugepage=", setup_transparent_hugepage);
-pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma, bool dirty)
+pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
{
- if (likely(vma->vm_flags & VM_WRITE)) {
+ if (likely(vma->vm_flags & VM_WRITE))
pmd = pmd_mkwrite(pmd);
- if (dirty)
- pmd = pmd_mkdirty(pmd);
- }
return pmd;
}
@@ -602,7 +599,7 @@
}
entry = mk_huge_pmd(page, vma->vm_page_prot);
- entry = maybe_pmd_mkwrite(entry, vma, true);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
page_add_new_anon_rmap(page, vma, haddr, true);
mem_cgroup_commit_charge(page, memcg, false, true);
lru_cache_add_active_or_unevictable(page, vma);
@@ -744,8 +741,8 @@
if (pfn_t_devmap(pfn))
entry = pmd_mkdevmap(entry);
if (write) {
- entry = pmd_mkyoung(entry);
- entry = maybe_pmd_mkwrite(entry, vma, true);
+ entry = pmd_mkyoung(pmd_mkdirty(entry));
+ entry = maybe_pmd_mkwrite(entry, vma);
}
if (pgtable) {
@@ -791,14 +788,10 @@
EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd);
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
-static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma,
- bool dirty)
+static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma)
{
- if (likely(vma->vm_flags & VM_WRITE)) {
+ if (likely(vma->vm_flags & VM_WRITE))
pud = pud_mkwrite(pud);
- if (dirty)
- pud = pud_mkdirty(pud);
- }
return pud;
}
@@ -814,8 +807,8 @@
if (pfn_t_devmap(pfn))
entry = pud_mkdevmap(entry);
if (write) {
- entry = pud_mkyoung(entry);
- entry = maybe_pud_mkwrite(entry, vma, true);
+ entry = pud_mkyoung(pud_mkdirty(entry));
+ entry = maybe_pud_mkwrite(entry, vma);
}
set_pud_at(mm, addr, pud, entry);
update_mmu_cache_pud(vma, addr, pud);
@@ -1286,7 +1279,7 @@
if (reuse_swap_page(page, NULL)) {
pmd_t entry;
entry = pmd_mkyoung(orig_pmd);
- entry = maybe_pmd_mkwrite(entry, vma, true);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
if (pmdp_set_access_flags(vma, haddr, vmf->pmd, entry, 1))
update_mmu_cache_pmd(vma, vmf->address, vmf->pmd);
ret |= VM_FAULT_WRITE;
@@ -1356,7 +1349,7 @@
} else {
pmd_t entry;
entry = mk_huge_pmd(new_page, vma->vm_page_prot);
- entry = maybe_pmd_mkwrite(entry, vma, true);
+ entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
pmdp_huge_clear_flush_notify(vma, haddr, vmf->pmd);
page_add_new_anon_rmap(new_page, vma, haddr, true);
mem_cgroup_commit_charge(new_page, memcg, false, true);
@@ -2935,7 +2928,7 @@
if (pmd_swp_soft_dirty(*pvmw->pmd))
pmde = pmd_mksoft_dirty(pmde);
if (is_write_migration_entry(entry))
- pmde = maybe_pmd_mkwrite(pmde, vma, false);
+ pmde = maybe_pmd_mkwrite(pmde, vma);
flush_cache_range(vma, mmun_start, mmun_start + HPAGE_PMD_SIZE);
page_add_anon_rmap(new, vma, mmun_start, true);