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authorJan Beulich <JBeulich@suse.com>2012-01-18 13:29:59 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2012-01-24 20:26:10 -0200
commite3e877e79b7c6a322f9f628e87052c13581238cc (patch)
tree0f68ae300a31a0124552ce6eb6a511aea19d10b5 /tools/perf/bench/mem-memcpy.c
parentbe3de80dc2e671d9ee15e69fe9cd84d2b71e2225 (diff)
perf bench: Allow passing an iteration count to "bench mem mem{cpy,set}"
"perf stat ... perf bench mem mem..." is pretty meaningless when using small block sizes (as the overhead of the invocation of each test run basically hides the actual test result in the noise). Repeating the actually interesting function's invocation a number of times allows the results to become meaningful. Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F16D767020000780006D738@nat28.tlf.novell.com Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/bench/mem-memcpy.c')
-rw-r--r--tools/perf/bench/mem-memcpy.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/tools/perf/bench/mem-memcpy.c b/tools/perf/bench/mem-memcpy.c
index db82021f4b91..6ad2b1c6b27b 100644
--- a/tools/perf/bench/mem-memcpy.c
+++ b/tools/perf/bench/mem-memcpy.c
@@ -24,6 +24,7 @@
static const char *length_str = "1MB";
static const char *routine = "default";
+static int iterations = 1;
static bool use_clock;
static int clock_fd;
static bool only_prefault;
@@ -35,6 +36,8 @@ static const struct option options[] = {
"available unit: B, MB, GB (upper and lower)"),
OPT_STRING('r', "routine", &routine, "default",
"Specify routine to copy"),
+ OPT_INTEGER('i', "iterations", &iterations,
+ "repeat memcpy() invocation this number of times"),
OPT_BOOLEAN('c', "clock", &use_clock,
"Use CPU clock for measuring"),
OPT_BOOLEAN('o', "only-prefault", &only_prefault,
@@ -121,6 +124,7 @@ static u64 do_memcpy_clock(memcpy_t fn, size_t len, bool prefault)
{
u64 clock_start = 0ULL, clock_end = 0ULL;
void *src = NULL, *dst = NULL;
+ int i;
alloc_mem(&src, &dst, len);
@@ -128,7 +132,8 @@ static u64 do_memcpy_clock(memcpy_t fn, size_t len, bool prefault)
fn(dst, src, len);
clock_start = get_clock();
- fn(dst, src, len);
+ for (i = 0; i < iterations; ++i)
+ fn(dst, src, len);
clock_end = get_clock();
free(src);
@@ -140,6 +145,7 @@ static double do_memcpy_gettimeofday(memcpy_t fn, size_t len, bool prefault)
{
struct timeval tv_start, tv_end, tv_diff;
void *src = NULL, *dst = NULL;
+ int i;
alloc_mem(&src, &dst, len);
@@ -147,7 +153,8 @@ static double do_memcpy_gettimeofday(memcpy_t fn, size_t len, bool prefault)
fn(dst, src, len);
BUG_ON(gettimeofday(&tv_start, NULL));
- fn(dst, src, len);
+ for (i = 0; i < iterations; ++i)
+ fn(dst, src, len);
BUG_ON(gettimeofday(&tv_end, NULL));
timersub(&tv_end, &tv_start, &tv_diff);