From: John Hubbard <jhubbard@nvidia.com>
To: Shuah Khan <shuah@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Reinette Chatre <reinette.chatre@intel.com>,
Valentin Obst <kernel@valentinobst.de>,
linux-kselftest@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>,
llvm@lists.linux.dev, John Hubbard <jhubbard@nvidia.com>
Subject: [PATCH] selftests/resctrl: fix clang build warnings related to abs(), labs() calls
Date: Thu, 2 May 2024 19:32:09 -0700 [thread overview]
Message-ID: <20240503023209.80787-1-jhubbard@nvidia.com> (raw)
First of all, in order to build with clang at all, one must first apply
Valentin Obst's build fix for LLVM [1]. Furthermore, for this particular
resctrl directory, my pending fix [2] must also be applied. Once those
fixes are in place, then when building with clang, via:
make LLVM=1 -C tools/testing/selftests
...two types of warnings occur:
warning: absolute value function 'abs' given an argument of type
'long' but has parameter of type 'int' which may cause truncation of
value
warning: taking the absolute value of unsigned type 'unsigned long'
has no effect
Fix these by:
a) using labs() in place of abs(), when long integers are involved, and
b) don't call labs() unnecessarily.
[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/
[2] https://lore.kernel.org/all/20240503021712.78601-1-jhubbard@nvidia.com/
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
tools/testing/selftests/resctrl/cmt_test.c | 4 ++--
tools/testing/selftests/resctrl/mba_test.c | 2 +-
tools/testing/selftests/resctrl/mbm_test.c | 2 +-
3 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
index a81f91222a89..05a241519ae8 100644
--- a/tools/testing/selftests/resctrl/cmt_test.c
+++ b/tools/testing/selftests/resctrl/cmt_test.c
@@ -40,11 +40,11 @@ static int show_results_info(unsigned long sum_llc_val, int no_of_bits,
int ret;
avg_llc_val = sum_llc_val / num_of_runs;
- avg_diff = (long)abs(cache_span - avg_llc_val);
+ avg_diff = (long)(cache_span - avg_llc_val);
diff_percent = ((float)cache_span - avg_llc_val) / cache_span * 100;
ret = platform && abs((int)diff_percent) > max_diff_percent &&
- abs(avg_diff) > max_diff;
+ labs(avg_diff) > max_diff;
ksft_print_msg("%s Check cache miss rate within %lu%%\n",
ret ? "Fail:" : "Pass:", max_diff_percent);
diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c
index 7946e32e85c8..673b2bb800f7 100644
--- a/tools/testing/selftests/resctrl/mba_test.c
+++ b/tools/testing/selftests/resctrl/mba_test.c
@@ -77,7 +77,7 @@ static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1);
avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1);
- avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
+ avg_diff = (float)(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
avg_diff_per = (int)(avg_diff * 100);
ksft_print_msg("%s Check MBA diff within %d%% for schemata %u\n",
diff --git a/tools/testing/selftests/resctrl/mbm_test.c b/tools/testing/selftests/resctrl/mbm_test.c
index d67ffa3ec63a..c873793d016d 100644
--- a/tools/testing/selftests/resctrl/mbm_test.c
+++ b/tools/testing/selftests/resctrl/mbm_test.c
@@ -33,7 +33,7 @@ show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, size_t span)
avg_bw_imc = sum_bw_imc / 4;
avg_bw_resc = sum_bw_resc / 4;
- avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
+ avg_diff = (float)(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
avg_diff_per = (int)(avg_diff * 100);
ret = avg_diff_per > MAX_DIFF_PERCENT;
base-commit: f03359bca01bf4372cf2c118cd9a987a5951b1c8
prerequisite-patch-id: b901ece2a5b78503e2fb5480f20e304d36a0ea27
prerequisite-patch-id: 8d96c4b8c3ed6d9ea2588ef7f594ae0f9f83c279
--
2.45.0
next reply other threads:[~2024-05-03 2:32 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-03 2:32 John Hubbard [this message]
2024-05-03 8:00 ` [PATCH] selftests/resctrl: fix clang build warnings related to abs(), labs() calls Ilpo Järvinen
2024-05-03 16:52 ` John Hubbard
2024-05-03 18:37 ` Reinette Chatre
2024-05-03 19:12 ` John Hubbard
2024-05-03 20:46 ` Reinette Chatre
2024-05-03 22:00 ` John Hubbard
2024-05-06 9:07 ` Ilpo Järvinen
2024-05-06 17:21 ` John Hubbard
-- strict thread matches above, loose matches on Subject: below --
2024-05-08 19:02 John Hubbard
2024-05-08 19:39 ` John Hubbard
2024-05-10 9:06 ` Ilpo Järvinen
2024-05-10 18:01 ` John Hubbard
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