From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754731AbbJ0I4j (ORCPT ); Tue, 27 Oct 2015 04:56:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35063 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754573AbbJ0I4f (ORCPT ); Tue, 27 Oct 2015 04:56:35 -0400 From: Vitaly Kuznetsov To: Rasmus Villemoes Cc: Andrew Morton , Andy Shevchenko , Ulf Hansson , James Bottomley , Kees Cook , linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] lib/test-string_helpers.c: add string_get_size() tests References: <1445867720-25473-1-git-send-email-vkuznets@redhat.com> <1445867720-25473-4-git-send-email-vkuznets@redhat.com> <87y4ep5m9b.fsf@rasmusvillemoes.dk> Date: Tue, 27 Oct 2015 09:56:31 +0100 In-Reply-To: <87y4ep5m9b.fsf@rasmusvillemoes.dk> (Rasmus Villemoes's message of "Mon, 26 Oct 2015 22:54:24 +0100") Message-ID: <877fm8y9j4.fsf@vitty.brq.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Rasmus Villemoes writes: > On Mon, Oct 26 2015, Vitaly Kuznetsov wrote: > >> Add a couple of simple tests for string_get_size(). >> >> Signed-off-by: Vitaly Kuznetsov >> --- >> 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"); > Nice idea, will do. > Do we really care how and if string_get_size works for a non-power-of-2 > blk_size? Probably not but there is nothing in current algorithm which prevents it from working correctly with a non-power-of-2 blk_sizes. The issue you found is even more visible on (3000, 1900) test. > I certainly assume that we're passed a non-zero value. Oh crap, we don't have a check for blk_size = 0 and this leads to an infinite loop now... will do something in v2. > > Rasmus -- Vitaly