Memory addressing test implemented.

src/memtest.c

@@ -56,6 +56,33 @@ void memtest_progress_step(size_t curr, size_t size, char c) {
     fflush(stdout);
 }
 
+/* Test that addressing is fine. Every location is populated with its own
+ * address, and finally verified. This test is very fast but may detect
+ * ASAP big issues with the memory subsystem. */
+void memtest_addressing(unsigned long *l, size_t bytes) {
+    unsigned long words = bytes/sizeof(unsigned long);
+    unsigned long j, *p;
+
+    /* Fill */
+    p = l;
+    for (j = 0; j < words; j++) {
+        *p = (unsigned long)p;
+        p++;
+        if ((j & 0xffff) == 0) memtest_progress_step(j,words*2,'A');
+    }
+    /* Test */
+    p = l;
+    for (j = 0; j < words; j++) {
+        if (*p != (unsigned long)p) {
+            printf("\n*** MEMORY ADDRESSING ERROR: %p contains %lu\n",
+                (void*) p, *p);
+            exit(1);
+        }
+        p++;
+        if ((j & 0xffff) == 0) memtest_progress_step(j+words,words*2,'A');
+    }
+}
+
 /* Fill words stepping a single page at every write, so we continue to
  * touch all the pages in the smallest amount of time reducing the
  * effectiveness of caches, and making it hard for the OS to transfer
@@ -162,6 +189,11 @@ void memtest_test(size_t megabytes, int passes) {
     }
     while (pass != passes) {
         pass++;
+
+        memtest_progress_start("Addressing test",pass);
+        memtest_addressing(m,bytes);
+        memtest_progress_end();
+
         memtest_progress_start("Random fill",pass);
         memtest_fill_random(m,bytes);
         memtest_progress_end();