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-rw-r--r--mm/huge_memory.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 33ee637648b..e10d780c478 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1295,13 +1295,14 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
if (current_nid == numa_node_id())
count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL);
- target_nid = mpol_misplaced(page, vma, haddr);
- if (target_nid == -1) {
- put_page(page);
- goto clear_pmdnuma;
- }
+ /*
+ * Acquire the page lock to serialise THP migrations but avoid dropping
+ * page_table_lock if at all possible
+ */
+ if (trylock_page(page))
+ goto got_lock;
- /* Acquire the page lock to serialise THP migrations */
+ /* Serialise against migrationa and check placement check placement */
spin_unlock(&mm->page_table_lock);
lock_page(page);
@@ -1312,9 +1313,17 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
put_page(page);
goto out_unlock;
}
- spin_unlock(&mm->page_table_lock);
+
+got_lock:
+ target_nid = mpol_misplaced(page, vma, haddr);
+ if (target_nid == -1) {
+ unlock_page(page);
+ put_page(page);
+ goto clear_pmdnuma;
+ }
/* Migrate the THP to the requested node */
+ spin_unlock(&mm->page_table_lock);
migrated = migrate_misplaced_transhuge_page(mm, vma,
pmdp, pmd, addr, page, target_nid);
if (!migrated)