From 1182f883113483cefbc3be0178a2df2dc9ae8b77 Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Tue, 2 Dec 2014 16:50:41 +0100 Subject: [PATCH] perf bench: Fix memcpy/memset output The memcpy and memset benchmarks return bogus results when iterations > 0 because the iterations value is not taken into account when calculating the final result: $ perf bench mem memset --only-prefault --length 1GB --iterations 1 # Running 'mem/memset' benchmark: # Copying 1GB Bytes ... 20.798669 GB/Sec (with prefault) $ perf bench mem memset --only-prefault --length 1GB --iterations 10 # Running 'mem/memset' benchmark: # Copying 1GB Bytes ... 2.086576 GB/Sec (with prefault) $ perf bench mem memset --only-prefault --length 1GB --iterations 100 # Running 'mem/memset' benchmark: # Copying 1GB Bytes ... 212.840917 MB/Sec (with prefault) Fix this. Signed-off-by: Rabin Vincent Acked-by: Ingo Molnar Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Rabin Vincent Cc: Rabin Vincent Link: http://lkml.kernel.org/r/1417535441-3965-3-git-send-email-rabin.vincent@axis.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/bench/mem-memcpy.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/tools/perf/bench/mem-memcpy.c b/tools/perf/bench/mem-memcpy.c index e18be70c8a47..6c14afe8c1b1 100644 --- a/tools/perf/bench/mem-memcpy.c +++ b/tools/perf/bench/mem-memcpy.c @@ -141,6 +141,7 @@ static int bench_mem_common(int argc, const char **argv, { int i; size_t len; + double totallen; double result_bps[2]; u64 result_cycle[2]; @@ -156,6 +157,7 @@ static int bench_mem_common(int argc, const char **argv, init_cycle(); len = (size_t)perf_atoll((char *)length_str); + totallen = (double)len * iterations; result_cycle[0] = result_cycle[1] = 0ULL; result_bps[0] = result_bps[1] = 0.0; @@ -219,10 +221,10 @@ static int bench_mem_common(int argc, const char **argv, if (use_cycle) { printf(" %14lf Cycle/Byte\n", (double)result_cycle[0] - / (double)len); + / totallen); printf(" %14lf Cycle/Byte (with prefault)\n", (double)result_cycle[1] - / (double)len); + / totallen); } else { print_bps(result_bps[0]); printf("\n"); @@ -233,7 +235,7 @@ static int bench_mem_common(int argc, const char **argv, if (use_cycle) { printf(" %14lf Cycle/Byte", (double)result_cycle[pf] - / (double)len); + / totallen); } else print_bps(result_bps[pf]); @@ -244,8 +246,8 @@ static int bench_mem_common(int argc, const char **argv, if (!only_prefault && !no_prefault) { if (use_cycle) { printf("%lf %lf\n", - (double)result_cycle[0] / (double)len, - (double)result_cycle[1] / (double)len); + (double)result_cycle[0] / totallen, + (double)result_cycle[1] / totallen); } else { printf("%lf %lf\n", result_bps[0], result_bps[1]); @@ -253,7 +255,7 @@ static int bench_mem_common(int argc, const char **argv, } else { if (use_cycle) { printf("%lf\n", (double)result_cycle[pf] - / (double)len); + / totallen); } else printf("%lf\n", result_bps[pf]); } @@ -324,7 +326,7 @@ static double do_memcpy_gettimeofday(const struct routine *r, size_t len, free(src); free(dst); - return (double)((double)len / timeval2double(&tv_diff)); + return (double)(((double)len * iterations) / timeval2double(&tv_diff)); } int bench_mem_memcpy(int argc, const char **argv, @@ -389,7 +391,7 @@ static double do_memset_gettimeofday(const struct routine *r, size_t len, timersub(&tv_end, &tv_start, &tv_diff); free(dst); - return (double)((double)len / timeval2double(&tv_diff)); + return (double)(((double)len * iterations) / timeval2double(&tv_diff)); } static const char * const bench_mem_memset_usage[] = { -- 2.20.1