On Thu, 2 May 2024, John Hubbard wrote: > 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@xxxxxxxxxxxxxxx/ > [2] https://lore.kernel.org/all/20240503021712.78601-1-jhubbard@xxxxxxxxxx/ > > Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx> > --- > 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); This seems fine but... > 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; But how are these two cases same after your change when you ended up removing taking the absolute value entirely? -- i.
