[PATCH] flush_cache_mm in zap_page_range

unmap_vmas() eventually calls tlb_start_vma(), where most architectures
flush caches as necessary.  The flush here seems to make the
flush_cache_range() in zap_page_range() redundant, and therefore can be
removed.

mm/memory.c

@@ -601,7 +601,6 @@ void zap_page_range(struct vm_area_struct *vma,
 
 	lru_add_drain();
 	spin_lock(&mm->page_table_lock);
-	flush_cache_range(vma, address, end);
 	tlb = tlb_gather_mmu(mm, 0);
 	unmap_vmas(&tlb, mm, vma, address, end, &nr_accounted);
 	tlb_finish_mmu(tlb, address, end);