Re: [PATCH 3/3] lib/test-string_helpers.c: add string_get_size() tests

From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	James Bottomley <JBottomley@Odin.com>,
	Kees Cook <keescook@chromium.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/3] lib/test-string_helpers.c: add string_get_size() tests
Date: Mon, 26 Oct 2015 22:54:24 +0100	[thread overview]
Message-ID: <87y4ep5m9b.fsf@rasmusvillemoes.dk> (raw)
In-Reply-To: <1445867720-25473-4-git-send-email-vkuznets@redhat.com> (Vitaly Kuznetsov's message of "Mon, 26 Oct 2015 14:55:20 +0100")

On Mon, Oct 26 2015, Vitaly Kuznetsov <vkuznets@redhat.com> wrote:

> Add a couple of simple tests for string_get_size().
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
>  lib/test-string_helpers.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 44 insertions(+)
>
> diff --git a/lib/test-string_helpers.c b/lib/test-string_helpers.c
> index 8e376ef..a158cb3 100644
> --- a/lib/test-string_helpers.c
> +++ b/lib/test-string_helpers.c
> @@ -326,6 +326,47 @@ out:
>  	kfree(out_test);
>  }
>  
> +#define string_get_size_maxbuf 16
> +#define test_string_get_size_one(size, blk_size, units, exp_result)            \
> +	do {                                                                   \
> +		BUILD_BUG_ON(sizeof(exp_result) >= string_get_size_maxbuf);    \
> +		__test_string_get_size((size), (blk_size), (units),            \
> +				       (exp_result));                          \
> +	} while (0)
> +
> +
> +static __init void __test_string_get_size(const u64 size, const u32 blk_size,
> +					  const enum string_size_units units,
> +					  const char *exp_result)
> +{
> +	char buf[string_get_size_maxbuf];
> +
> +	string_get_size(size, blk_size, units, buf, sizeof(buf));
> +	if (!memcmp(buf, exp_result, strlen(exp_result) + 1))
> +		return;
> +
> +	buf[sizeof(buf) - 1] = '\0';
> +	pr_warn("Test 'test_string_get_size_one' failed!\n");
> +	pr_warn("string_get_size(size = %llu, blk_size = %u, units = %d\n",
> +		size, blk_size, units);
> +	pr_warn("expected: '%s', got '%s'\n", exp_result, buf);
> +}
> +
> +static __init void test_string_get_size(void)
> +{
> +	test_string_get_size_one(16384, 512, STRING_UNITS_2, "8.00 MiB");
> +	test_string_get_size_one(500118192, 512, STRING_UNITS_2, "238 GiB");
> +	test_string_get_size_one(8192, 4096, STRING_UNITS_10, "33.5 MB");
> +	test_string_get_size_one(1100, 1, STRING_UNITS_10, "1.10 kB");
> +	test_string_get_size_one(3000, 1900, STRING_UNITS_10, "5.70 MB");
> +	test_string_get_size_one(151234561234657, 3456789, STRING_UNITS_10,
> +				 "522 EB");

Since we're changing this anyway, can't we test every pair of
(size,blk_size) with both units? That'll be twice the number of tests
for less horizontal real estate. E.g.

  test_string_get_size_one(8192, 4096, "32.0 MiB", "33.5 MB");

Do we really care how and if string_get_size works for a non-power-of-2
blk_size? I certainly assume that we're passed a non-zero value.

Rasmus