Re: [PATCH V2] selftests/vm: Add tests to validate mirror functionality with mremap

[Michal Hocko]

On Tue 25-07-17 12:06:57, Anshuman Khandual wrote:
[...]
> diff --git a/tools/testing/selftests/vm/mremap_mirror_private_anon.c b/tools/testing/selftests/vm/mremap_mirror_private_anon.c
[...]
> +	ptr = mmap(NULL, alloc_size, PROT_READ | PROT_WRITE,
> +			MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
> +	if (ptr == MAP_FAILED) {
> +		perror("map() failed");
> +		return -1;
> +	}
> +	memset(ptr, PATTERN, alloc_size);
> +
> +	mirror_ptr =  (char *) mremap(ptr, 0, alloc_size, MREMAP_MAYMOVE);
> +	if (mirror_ptr == MAP_FAILED) {
> +		perror("mremap() failed");
> +		return -1;
> +	}

What is the point of this test? It will break with Mike's patch very
soon. Btw. it never worked. 
-- 
Michal Hocko
SUSE Labs