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* [PATCH 4/4] perf/x86-64: allow passing an iteration count to "bench mem mem{cpy,set}"
@ 2012-01-18 13:29 Jan Beulich
  2012-01-26 13:34 ` [tip:perf/core] perf bench: Allow passing an iteration count to " bench " tip-bot for Jan Beulich
  0 siblings, 1 reply; 2+ messages in thread
From: Jan Beulich @ 2012-01-18 13:29 UTC (permalink / raw)
  To: a.p.zijlstra, mingo, acme, paulus; +Cc: linux-kernel

"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.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- 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, 
 {
 	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, 
 		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(mem
 {
 	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(mem
 		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);
--- a/tools/perf/bench/mem-memset.c
+++ b/tools/perf/bench/mem-memset.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 memset() invocation this number of times"),
 	OPT_BOOLEAN('c', "clock", &use_clock,
 		    "Use CPU clock for measuring"),
 	OPT_BOOLEAN('o', "only-prefault", &only_prefault,
@@ -117,6 +120,7 @@ static u64 do_memset_clock(memset_t fn, 
 {
 	u64 clock_start = 0ULL, clock_end = 0ULL;
 	void *dst = NULL;
+	int i;
 
 	alloc_mem(&dst, len);
 
@@ -124,7 +128,8 @@ static u64 do_memset_clock(memset_t fn, 
 		fn(dst, -1, len);
 
 	clock_start = get_clock();
-	fn(dst, 0, len);
+	for (i = 0; i < iterations; ++i)
+		fn(dst, i, len);
 	clock_end = get_clock();
 
 	free(dst);
@@ -135,6 +140,7 @@ static double do_memset_gettimeofday(mem
 {
 	struct timeval tv_start, tv_end, tv_diff;
 	void *dst = NULL;
+	int i;
 
 	alloc_mem(&dst, len);
 
@@ -142,7 +148,8 @@ static double do_memset_gettimeofday(mem
 		fn(dst, -1, len);
 
 	BUG_ON(gettimeofday(&tv_start, NULL));
-	fn(dst, 0, len);
+	for (i = 0; i < iterations; ++i)
+		fn(dst, i, len);
 	BUG_ON(gettimeofday(&tv_end, NULL));
 
 	timersub(&tv_end, &tv_start, &tv_diff);




^ permalink raw reply	[flat|nested] 2+ messages in thread
* [tip:perf/core] perf bench: Allow passing an iteration count to " bench mem mem{cpy,set}"
  2012-01-18 13:29 [PATCH 4/4] perf/x86-64: allow passing an iteration count to "bench mem mem{cpy,set}" Jan Beulich
@ 2012-01-26 13:34 ` tip-bot for Jan Beulich
  0 siblings, 0 replies; 2+ messages in thread
From: tip-bot for Jan Beulich @ 2012-01-26 13:34 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: acme, linux-kernel, paulus, hpa, mingo, a.p.zijlstra, jbeulich,
	JBeulich, tglx, mingo

Commit-ID:  e3e877e79b7c6a322f9f628e87052c13581238cc
Gitweb:     http://git.kernel.org/tip/e3e877e79b7c6a322f9f628e87052c13581238cc
Author:     Jan Beulich <JBeulich@suse.com>
AuthorDate: Wed, 18 Jan 2012 13:29:59 +0000
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 24 Jan 2012 20:26:10 -0200

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>
---
 tools/perf/bench/mem-memcpy.c |   11 +++++++++--
 tools/perf/bench/mem-memset.c |   11 +++++++++--
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/tools/perf/bench/mem-memcpy.c b/tools/perf/bench/mem-memcpy.c
index db82021..6ad2b1c 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);
diff --git a/tools/perf/bench/mem-memset.c b/tools/perf/bench/mem-memset.c
index 9c0c6f0..59d4933 100644
--- a/tools/perf/bench/mem-memset.c
+++ b/tools/perf/bench/mem-memset.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 memset() invocation this number of times"),
 	OPT_BOOLEAN('c', "clock", &use_clock,
 		    "Use CPU clock for measuring"),
 	OPT_BOOLEAN('o', "only-prefault", &only_prefault,
@@ -117,6 +120,7 @@ static u64 do_memset_clock(memset_t fn, size_t len, bool prefault)
 {
 	u64 clock_start = 0ULL, clock_end = 0ULL;
 	void *dst = NULL;
+	int i;
 
 	alloc_mem(&dst, len);
 
@@ -124,7 +128,8 @@ static u64 do_memset_clock(memset_t fn, size_t len, bool prefault)
 		fn(dst, -1, len);
 
 	clock_start = get_clock();
-	fn(dst, 0, len);
+	for (i = 0; i < iterations; ++i)
+		fn(dst, i, len);
 	clock_end = get_clock();
 
 	free(dst);
@@ -135,6 +140,7 @@ static double do_memset_gettimeofday(memset_t fn, size_t len, bool prefault)
 {
 	struct timeval tv_start, tv_end, tv_diff;
 	void *dst = NULL;
+	int i;
 
 	alloc_mem(&dst, len);
 
@@ -142,7 +148,8 @@ static double do_memset_gettimeofday(memset_t fn, size_t len, bool prefault)
 		fn(dst, -1, len);
 
 	BUG_ON(gettimeofday(&tv_start, NULL));
-	fn(dst, 0, len);
+	for (i = 0; i < iterations; ++i)
+		fn(dst, i, len);
 	BUG_ON(gettimeofday(&tv_end, NULL));
 
 	timersub(&tv_end, &tv_start, &tv_diff);

^ permalink raw reply related	[flat|nested] 2+ messages in thread
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2012-01-18 13:29 [PATCH 4/4] perf/x86-64: allow passing an iteration count to "bench mem mem{cpy,set}" Jan Beulich
2012-01-26 13:34 ` [tip:perf/core] perf bench: Allow passing an iteration count to " bench " tip-bot for Jan Beulich

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