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-rw-r--r--mm/huge_memory.c25
1 files changed, 15 insertions, 10 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index fc00c8cb5a82..6817b0350c71 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1260,6 +1260,7 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
int target_nid, last_cpupid = -1;
bool page_locked;
bool migrated = false;
+ bool was_writable;
int flags = 0;
/* A PROT_NONE fault should not end up here */
@@ -1291,12 +1292,8 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
flags |= TNF_FAULT_LOCAL;
}
- /*
- * Avoid grouping on DSO/COW pages in specific and RO pages
- * in general, RO pages shouldn't hurt as much anyway since
- * they can be in shared cache state.
- */
- if (!pmd_write(pmd))
+ /* See similar comment in do_numa_page for explanation */
+ if (!(vma->vm_flags & VM_WRITE))
flags |= TNF_NO_GROUP;
/*
@@ -1353,12 +1350,17 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
if (migrated) {
flags |= TNF_MIGRATED;
page_nid = target_nid;
- }
+ } else
+ flags |= TNF_MIGRATE_FAIL;
goto out;
clear_pmdnuma:
BUG_ON(!PageLocked(page));
+ was_writable = pmd_write(pmd);
pmd = pmd_modify(pmd, vma->vm_page_prot);
+ pmd = pmd_mkyoung(pmd);
+ if (was_writable)
+ pmd = pmd_mkwrite(pmd);
set_pmd_at(mm, haddr, pmdp, pmd);
update_mmu_cache_pmd(vma, addr, pmdp);
unlock_page(page);
@@ -1482,6 +1484,8 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
pmd_t entry;
+ bool preserve_write = prot_numa && pmd_write(*pmd);
+ ret = 1;
/*
* Avoid trapping faults against the zero page. The read-only
@@ -1490,16 +1494,17 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
*/
if (prot_numa && is_huge_zero_pmd(*pmd)) {
spin_unlock(ptl);
- return 0;
+ return ret;
}
if (!prot_numa || !pmd_protnone(*pmd)) {
- ret = 1;
entry = pmdp_get_and_clear_notify(mm, addr, pmd);
entry = pmd_modify(entry, newprot);
+ if (preserve_write)
+ entry = pmd_mkwrite(entry);
ret = HPAGE_PMD_NR;
set_pmd_at(mm, addr, pmd, entry);
- BUG_ON(pmd_write(entry));
+ BUG_ON(!preserve_write && pmd_write(entry));
}
spin_unlock(ptl);
}