[dpdk-dev] [PATCH] test: provide performance difference ratio and test time

[Herbert Guan]

The printed time values presented in TSC is not straight forward
showing the performance difference.  And if the high resolution
counter is not enabled, time value is too small to show the actual
performance (e.g. "1 - 1" seems the same but in fact the perfomance
diffs by 50% or more).
With the performance difference ratio caculated and printed, it'll be
easier for people to read and compare the performance between
rte_memcpy() and memcpy().
Since the TSC values' units may diff a lot on different platforms,
the total execution time of aligned/unaligned memcpy test are
provided to allow comparation between platforms.

Signed-off-by: Herbert Guan <herbert.guan at arm.com>
---
 test/test/test_memcpy_perf.c | 50 +++++++++++++++++++++++++++++++++-----------
 1 file changed, 38 insertions(+), 12 deletions(-)

diff --git a/test/test/test_memcpy_perf.c b/test/test/test_memcpy_perf.c
index 91de856..b23026b 100644
--- a/test/test/test_memcpy_perf.c
+++ b/test/test/test_memcpy_perf.c
@@ -35,6 +35,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <sys/time.h>
 
 #include <rte_common.h>
 #include <rte_cycles.h>
@@ -241,8 +242,9 @@
             memcpy(dst+dst_addrs[t], src+src_addrs[t], size);               \
         total_time2 += rte_rdtsc() - start_time;                            \
     }                                                                       \
-    printf("%8.0f -",  (double)total_time /TEST_ITERATIONS);                \
-    printf("%5.0f",  (double)total_time2 / TEST_ITERATIONS);                \
+    printf("%3.0f -",  (double)total_time / TEST_ITERATIONS);                \
+    printf("%3.0f",  (double)total_time2 / TEST_ITERATIONS);                \
+    printf("(%6.2f%%) ", ((double)total_time - total_time2)*100/total_time2);  \
 } while (0)
 
 /* Run aligned memcpy tests for each cached/uncached permutation */
@@ -324,6 +326,9 @@
 perf_test(void)
 {
 	int ret;
+	struct timeval tv_begin, tv_end;
+	double time_aligned, time_unaligned;
+	double time_aligned_const, time_unaligned_const;
 
 	ret = init_buffers();
 	if (ret != 0)
@@ -340,26 +345,47 @@
 	do_uncached_write(large_buf_write, 0, small_buf_read, 1, SMALL_BUFFER_SIZE);
 
 	printf("\n** rte_memcpy() - memcpy perf. tests (C = compile-time constant) **\n"
-		   "======= ============== ============== ============== ==============\n"
-		   "   Size Cache to cache   Cache to mem   Mem to cache     Mem to mem\n"
-		   "(bytes)        (ticks)        (ticks)        (ticks)        (ticks)\n"
-		   "------- -------------- -------------- -------------- --------------");
+		   "======= ================= ================= ================= =================\n"
+		   "   Size   Cache to cache     Cache to mem      Mem to cache        Mem to mem\n"
+		   "(bytes)          (ticks)          (ticks)           (ticks)           (ticks)\n"
+		   "------- ----------------- ----------------- ----------------- -----------------");
 
-	printf("\n========================= %2dB aligned ============================",
+	printf("\n================================= %2dB aligned =================================",
 		alignment_unit);
 	/* Do aligned tests where size is a variable */
+	gettimeofday(&tv_begin, NULL);
 	perf_test_variable_aligned();
-	printf("\n------- -------------- -------------- -------------- --------------");
+	gettimeofday(&tv_end, NULL);
+	time_aligned = (double)(tv_end.tv_sec - tv_begin.tv_sec)
+		+ ((double)tv_end.tv_usec - tv_begin.tv_usec)/1000000;
+	printf("\n------- ----------------- ----------------- ----------------- -----------------");
 	/* Do aligned tests where size is a compile-time constant */
+	gettimeofday(&tv_begin, NULL);
 	perf_test_constant_aligned();
-	printf("\n=========================== Unaligned =============================");
+	gettimeofday(&tv_end, NULL);
+	time_aligned_const = (double)(tv_end.tv_sec - tv_begin.tv_sec)
+		+ ((double)tv_end.tv_usec - tv_begin.tv_usec)/1000000;
+	printf("\n================================== Unaligned ==================================");
 	/* Do unaligned tests where size is a variable */
+	gettimeofday(&tv_begin, NULL);
 	perf_test_variable_unaligned();
-	printf("\n------- -------------- -------------- -------------- --------------");
+	gettimeofday(&tv_end, NULL);
+	time_unaligned = (double)(tv_end.tv_sec - tv_begin.tv_sec)
+		+ ((double)tv_end.tv_usec - tv_begin.tv_usec)/1000000;
+	printf("\n------- ----------------- ----------------- ----------------- -----------------");
 	/* Do unaligned tests where size is a compile-time constant */
+	gettimeofday(&tv_begin, NULL);
 	perf_test_constant_unaligned();
-	printf("\n======= ============== ============== ============== ==============\n\n");
-
+	gettimeofday(&tv_end, NULL);
+	time_unaligned_const = (double)(tv_end.tv_sec - tv_begin.tv_sec)
+		+ ((double)tv_end.tv_usec - tv_begin.tv_usec)/1000000;
+	printf("\n======= ================= ================= ================= =================\n\n");
+
+	printf("Test Execution Time (seconds):\n");
+	printf("Aligned variable copy size   = %8.3f\n", time_aligned);
+	printf("Aligned constant copy size   = %8.3f\n", time_aligned_const);
+	printf("Unaligned variable copy size = %8.3f\n", time_unaligned);
+	printf("Unaligned constant copy size = %8.3f\n", time_unaligned_const);
 	free_buffers();
 
 	return 0;
-- 
1.8.3.1