diff --git a/tests/unistd_test.cpp b/tests/unistd_test.cpp
index 4c21627..b639a4e 100644
--- a/tests/unistd_test.cpp
+++ b/tests/unistd_test.cpp
@@ -1166,6 +1166,26 @@
   VERIFY_SYSCONF_UNKNOWN(666);
 }
 
+static void show_cache(const char* name, long size, long assoc, long line_size) {
+  printf("%s cache size: %ld bytes, line size %ld bytes, ", name, size, line_size);
+  if (assoc == 0) {
+    printf("fully");
+  } else {
+    printf("%ld-way", assoc);
+  }
+  printf(" associative\n");
+}
+
+TEST(UNISTD_TEST, sysconf_cache) {
+  // It's not obvious we can _test_ any of these, but we can at least
+  // show the output for humans to inspect.
+  show_cache("L1D", sysconf(_SC_LEVEL1_DCACHE_SIZE), sysconf(_SC_LEVEL1_DCACHE_ASSOC), sysconf(_SC_LEVEL1_DCACHE_LINESIZE));
+  show_cache("L1I", sysconf(_SC_LEVEL1_ICACHE_SIZE), sysconf(_SC_LEVEL1_ICACHE_ASSOC), sysconf(_SC_LEVEL1_ICACHE_LINESIZE));
+  show_cache("L2", sysconf(_SC_LEVEL2_CACHE_SIZE), sysconf(_SC_LEVEL2_CACHE_ASSOC), sysconf(_SC_LEVEL2_CACHE_LINESIZE));
+  show_cache("L3", sysconf(_SC_LEVEL3_CACHE_SIZE), sysconf(_SC_LEVEL3_CACHE_ASSOC), sysconf(_SC_LEVEL3_CACHE_LINESIZE));
+  show_cache("L4", sysconf(_SC_LEVEL4_CACHE_SIZE), sysconf(_SC_LEVEL4_CACHE_ASSOC), sysconf(_SC_LEVEL4_CACHE_LINESIZE));
+}
+
 TEST(UNISTD_TEST, dup2_same) {
   // POSIX says of dup2:
   // If fildes2 is already a valid open file descriptor ...