diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index f6d91ecb80267840e8f3b17e10986a2af28ef6ec..e9736af126b29ee2083b6900e8354f820d5b02e8 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -210,8 +210,6 @@ void __iomem *ioremap(resource_size_t offset, unsigned long size);
 extern void iounmap(volatile void __iomem *addr);
 #define iounmap iounmap
 
-extern void set_iounmap_nonlazy(void);
-
 #ifdef __KERNEL__
 
 void memcpy_fromio(void *, const volatile void __iomem *, size_t);
diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index a7f617a3981d451c002317ac9bb64ab3baeaaa27..97529552dd2496421cd7f684c38e7a3629ad40c5 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -37,7 +37,6 @@ static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
 	} else
 		memcpy(buf, vaddr + offset, csize);
 
-	set_iounmap_nonlazy();
 	iounmap((void __iomem *)vaddr);
 	return csize;
 }
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index e163372d396798fdedb45e87964531f1599bb183..0b17498a34f1bf5bca97393de9f88929b00196f1 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1671,17 +1671,6 @@ static DEFINE_MUTEX(vmap_purge_lock);
 /* for per-CPU blocks */
 static void purge_fragmented_blocks_allcpus(void);
 
-#ifdef CONFIG_X86_64
-/*
- * called before a call to iounmap() if the caller wants vm_area_struct's
- * immediately freed.
- */
-void set_iounmap_nonlazy(void)
-{
-	atomic_long_set(&vmap_lazy_nr, lazy_max_pages()+1);
-}
-#endif /* CONFIG_X86_64 */
-
 /*
  * Purges all lazily-freed vmap areas.
  */