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-rw-r--r--mm/huge_memory.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 216114f..ce88345 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1410,6 +1410,7 @@ int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t pmd)
unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
int page_nid = -1, this_nid = numa_node_id();
int target_nid, last_cpupid = -1;
+ bool need_flush = false;
bool page_locked;
bool migrated = false;
bool was_writable;
@@ -1503,10 +1504,29 @@ int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t pmd)
flush_tlb_range(vma, haddr, haddr + HPAGE_PMD_SIZE);
/*
+ * Since we took the NUMA fault, we must have observed the !accessible
+ * bit. Make sure all other CPUs agree with that, to avoid them
+ * modifying the page we're about to migrate.
+ *
+ * Must be done under PTL such that we'll observe the relevant
+ * set_tlb_flush_pending().
+ */
+ if (mm_tlb_flush_pending(vma->vm_mm))
+ need_flush = true;
+
+ /*
* Migrate the THP to the requested node, returns with page unlocked
* and access rights restored.
*/
spin_unlock(vmf->ptl);
+
+ /*
+ * We are not sure a pending tlb flush here is for a huge page
+ * mapping or not. Hence use the tlb range variant
+ */
+ if (need_flush)
+ flush_tlb_range(vma, haddr, haddr + HPAGE_PMD_SIZE);
+
migrated = migrate_misplaced_transhuge_page(vma->vm_mm, vma,
vmf->pmd, pmd, vmf->address, page, target_nid);
if (migrated) {
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