Allow disabling read or write portion through arguments.

1 files changed, 32 insertions, 15 deletions

diff --git a/membw.c b/membw.c
index 0ae9d7b..6eb3b6c 100644
--- a/membw.c
+++ b/membw.c
@@ -36,7 +36,7 @@ static inline int64_t gettime(void)
 void print_usage(int argc, char **argv)
 {
     fprintf(stderr,
-            "Usage: %s <N> [repeats]\n"
+            "Usage: %s <N> [repeats] [rw]\n"
             "\tN: array size in kB\n",
             argv[0]);
 }
@@ -52,6 +52,8 @@ int main(int argc, char **argv)
     int64_t start;
     int64_t duration = 0;
 
+    int do_read = 1, do_write = 1;
+
     if (argc < 2) {
         print_usage(argc, argv);
         return 1;
@@ -73,33 +75,48 @@ int main(int argc, char **argv)
         }
     }
 
+    if (argc >= 4) {
+        do_read = 0;
+        do_write = 0;
+        for (int i = 0; argv[3][i]; i++) {
+            if (argv[3][i] == 'r')
+                do_read = 1;
+            if (argv[3][i] == 'w')
+                do_write = 1;
+        }
+    }
+
     ret = posix_memalign((void**)&mem, 64, N);
     if (ret != 0) {
         fprintf(stderr, "Error allocating memory\n");
         return 2;
     }
 
-    start = gettime();
+    if (do_write) {
+        start = gettime();
 
-    for (unsigned int i = 0; i < repeats; i++)
-        membw_mem_write_avx(mem, N);
+        for (unsigned int i = 0; i < repeats; i++)
+            membw_mem_write_avx(mem, N);
 
-    duration = gettime() - start;
+        duration = gettime() - start;
 
-    fprintf(stdout, "Written %u x %g MB in %g ms: write bandwidth: %g MB/s\n",
-            repeats, (double)N / (1024 * 1024), duration / 1e3,
-            (double)N * repeats / duration * 1e6 / (1024 * 1024));
+        fprintf(stdout, "Written %u x %g MB in %g ms: write bandwidth: %g MB/s\n",
+                repeats, (double)N / (1024 * 1024), duration / 1e3,
+                (double)N * repeats / duration * 1e6 / (1024 * 1024));
+    }
 
-    start = gettime();
+    if (do_read) {
+        start = gettime();
 
-    for (unsigned int i = 0; i < repeats; i++)
-        membw_mem_read_avx(mem, N);
+        for (unsigned int i = 0; i < repeats; i++)
+            membw_mem_read_avx(mem, N);
 
-    duration = gettime() - start;
+        duration = gettime() - start;
 
-    fprintf(stdout, "Read %u x %g MB in %g ms: read bandwidth: %g MB/s\n",
-            repeats, (double)N / (1024 * 1024), duration / 1e3,
-            (double)N * repeats / duration * 1e6 / (1024 * 1024));
+        fprintf(stdout, "Read %u x %g MB in %g ms: read bandwidth: %g MB/s\n",
+                repeats, (double)N / (1024 * 1024), duration / 1e3,
+                (double)N * repeats / duration * 1e6 / (1024 * 1024));
+    }
 
     free(mem);