measure run phases/iterations individually

Author: mvorisek

benchmark/benchmark.php

@@ -120,7 +120,7 @@ function runValgrindPhpCgiCommand(
 
     $profileOut = __DIR__ . "/profiles/callgrind.out.$name";
     if ($jit) {
-        $profileOut .= '.jit';
+        $profileOut .= '-jit';
     }
 
     $process = runCommand([
@@ -138,12 +138,32 @@ function runValgrindPhpCgiCommand(
         '-d opcache.validate_timestamps=0',
         ...$args,
     ]);
-    $totals = extractTotalsFromCallgrindFile($profileOut);
-    $instructions = $totals['Ir'];
-    if ($repeat > 1) {
-        $instructions = gmp_strval(gmp_div_q($instructions, $repeat));
+
+    // collect metrics for startup, each benchmark run and shutdown
+    $totalsAll = [];
+    foreach (['startup' => 1, ...range(2, $repeat + 1), 'shutdown' => ''] as $phase => $fileSuffix) {
+        $profileOutSpecific = $profileOut . '.' . $phase;
+        if (!rename($profileOut . ($fileSuffix === '' ? '' : '.' . $fileSuffix), $profileOutSpecific)) {
+            throw new \Exception('Expected callgrind file "' . $profileOutSpecific . '" does not exist');
+        }
+
+        $totalsAll[$phase] = extractTotalsFromCallgrindFile($profileOutSpecific);
     }
-    return ['instructions' => $instructions];
+
+    // mimic original logged "instructions" meaning:
+    // - the startup was not counted (only if repeats > 1)
+    // - repeats were counted without warmup, ie. only the last 50% repeats were counted
+    // - the shutdown was never counted
+    $warmTotals = array_map(static fn () => '0', array_first($totalsAll));
+    foreach ($repeat === 1 ? ['startup', 0] : range(intdiv($repeat, 2), $repeat - 1) as $phase) {
+        foreach ($totalsAll[$phase] as $kEvent => $v) {
+            $warmTotals[$kEvent] = gmp_strval(gmp_add($warmTotals[$kEvent], $v));
+        }
+    }
+    $instructions = gmp_strval(gmp_div_q($warmTotals['Ir'], intdiv($repeat + 1, 2)));
+    $res = ['instructions' => $instructions];
+
+    return $res;
 }
 
 /**

sapi/cgi/cgi_main.c

@@ -2233,17 +2233,6 @@ consult the installation file that came with this distribution, or visit \n\
 						if (comma) {
 							warmup_repeats = atoi(php_optarg);
 							repeats = atoi(comma + 1);
-#ifdef HAVE_VALGRIND
-							if (warmup_repeats > 0) {
-								CALLGRIND_STOP_INSTRUMENTATION;
-								/* We're not interested in measuring startup */
-								CALLGRIND_ZERO_STATS;
-# ifdef HAVE_VALGRIND_CACHEGRIND_H
-								CACHEGRIND_STOP_INSTRUMENTATION;
-								/* Zeroing stats is not supported for cachegrind. */
-# endif
-							}
-#endif
 						} else {
 							repeats = atoi(php_optarg);
 						}
@@ -2285,6 +2274,13 @@ consult the installation file that came with this distribution, or visit \n\
 		}
 #endif
 		while (!fastcgi || fcgi_accept_request(request) >= 0) {
+#ifdef HAVE_VALGRIND
+			if (benchmark) {
+				/* measure startup and each benchmark run separately */
+				CALLGRIND_DUMP_STATS;
+			}
+#endif
+
 			SG(server_context) = fastcgi ? (void *)request : (void *) 1;
 			init_request_info(request);
 
@@ -2443,15 +2439,6 @@ consult the installation file that came with this distribution, or visit \n\
 				}
 			} /* end !cgi && !fastcgi */
 
-#ifdef HAVE_VALGRIND
-			if (warmup_repeats == 0) {
-				CALLGRIND_START_INSTRUMENTATION;
-# ifdef HAVE_VALGRIND_CACHEGRIND_H
-				CACHEGRIND_START_INSTRUMENTATION;
-# endif
-			}
-#endif
-
 			/* request startup only after we've done all we can to
 			 * get path_translated */
 			if (php_request_startup() == FAILURE) {
@@ -2570,14 +2557,6 @@ consult the installation file that came with this distribution, or visit \n\
 				SG(request_info).query_string = NULL;
 			}
 
-#ifdef HAVE_VALGRIND
-			/* We're not interested in measuring shutdown */
-			CALLGRIND_STOP_INSTRUMENTATION;
-# ifdef HAVE_VALGRIND_CACHEGRIND_H
-			CACHEGRIND_STOP_INSTRUMENTATION;
-# endif
-#endif
-
 			if (!fastcgi) {
 				if (benchmark) {
 					if (warmup_repeats) {
@@ -2605,6 +2584,12 @@ consult the installation file that came with this distribution, or visit \n\
 					script_file = NULL;
 					goto do_repeat;
 				}
+
+#ifdef HAVE_VALGRIND
+				/* measure shutdown separately */
+				CALLGRIND_DUMP_STATS;
+#endif
+
 				break;
 			}