mm: use update_mmu_tlb() on the second thread

As message in commit 7df6769 ("mm/memory.c: Update local TLB if PTE
entry exists") said, we should update local TLB only on the second thread.
So in the do_anonymous_page() here, we should use update_mmu_tlb()
instead of update_mmu_cache() on the second thread.

As David pointed out, this is a performance improvement, not a
correctness fix.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Qi Zheng <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Bibo Mao <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Max Filippov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

mm/memory.c

@@ -4134,7 +4134,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address,
 			&vmf->ptl);
 	if (!pte_none(*vmf->pte)) {
-		update_mmu_cache(vma, vmf->address, vmf->pte);
+		update_mmu_tlb(vma, vmf->address, vmf->pte);
 		goto release;
 	}