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Commit 1182f883 authored by Rabin Vincent's avatar Rabin Vincent Committed by Arnaldo Carvalho de Melo
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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: default avatarRabin Vincent <rabin.vincent@axis.com>
Acked-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rabin Vincent <rabin@rab.in>
Cc: Rabin Vincent <rabinv@axis.com>
Link: http://lkml.kernel.org/r/1417535441-3965-3-git-send-email-rabin.vincent@axis.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 5bce1a57

tools/perf/bench/mem-memcpy.c

+10 −8
Original line number Diff line number Diff line
@@ -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[] = {