perf-map: add support for performance counters

This patch adds preliminary support for integrating with Linux kernel
performance counters. The perf tool is expected to pick up the
anonymous memory [address, size, symbol] mappings when producing reports
that we generate.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

Makefile

@@ -82,7 +82,8 @@ JIT_OBJS = \
 	jit/bc-offset-mapping.o \
 	jit/cu-mapping.o	\
 	jit/method.o		\
-	jit/nop-bc.o
+	jit/nop-bc.o		\
+	jit/perf-map.o
 
 VM_OBJS = \
 	vm/bitset.o		\

include/jit/compiler.h

@@ -66,6 +66,23 @@ void free_fixup_site(struct fixup_site *);
 void trampoline_add_fixup_site(struct jit_trampoline *, struct fixup_site *);
 unsigned char *fixup_site_addr(struct fixup_site *);
 
+const char *method_symbol(struct methodblock *method, char *symbol, size_t len);
+
+static inline const char *cu_symbol(struct compilation_unit *cu, char *symbol, size_t len)
+{
+	return method_symbol(cu->method, symbol, len);
+}
+
+static inline void *cu_native_ptr(struct compilation_unit *cu)
+{
+	return buffer_ptr(cu->objcode);
+}
+
+static inline unsigned long cu_native_size(struct compilation_unit *cu)
+{
+	return buffer_offset(cu->objcode);
+}
+
 static inline void *method_native_ptr(struct methodblock *method)
 {
 	return buffer_ptr(method->compilation_unit->objcode);

include/jit/perf-map.h

@@ -0,0 +1,7 @@
+#ifndef JATO_PERF_MAP_H
+#define JATO_PERF_MAP_H
+
+void perf_map_open(void);
+void perf_map_append(const char *symbol, unsigned long addr, unsigned long size);
+
+#endif /* JATO_PERF_MAP_H */

jit/compiler.c

@@ -12,6 +12,7 @@
 #include <jit/statement.h>
 #include <jit/bc-offset-mapping.h>
 #include <jit/exception.h>
+#include <jit/perf-map.h>
 
 #include <errno.h>
 #include <stdlib.h>
@@ -26,8 +27,11 @@ static void compile_error(struct compilation_unit *cu, int err)
 	       __func__, cu->method->name, cb->name, err);
 }
 
+#define SYMBOL_LEN 128
+
 int compile(struct compilation_unit *cu)
 {
+	char symbol[SYMBOL_LEN];
 	int err;
 
 	if (opt_trace_method)
@@ -89,6 +93,7 @@ int compile(struct compilation_unit *cu)
 
 	cu->is_compiled = true;
 
+	perf_map_append(cu_symbol(cu, symbol, SYMBOL_LEN), (unsigned long) cu_native_ptr(cu), cu_native_size(cu));
   out:
 	if (err)
 		compile_error(cu, err);

jit/method.c

@@ -44,3 +44,10 @@ bool is_jit_method(unsigned long eip)
 {
 	return eip >= (unsigned long)&etext;
 }
+
+const char *method_symbol(struct methodblock *method, char *symbol, size_t size)
+{
+	snprintf(symbol, size, "%s.%s%s", CLASS_CB(method->class)->name, method->name, method->type);
+
+	return symbol;
+}

jit/perf-map.c

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2009  Pekka Enberg
+ * 
+ * This file is released under the GPL version 2 with the following
+ * clarification and special exception:
+ *
+ *     Linking this library statically or dynamically with other modules is
+ *     making a combined work based on this library. Thus, the terms and
+ *     conditions of the GNU General Public License cover the whole
+ *     combination.
+ *
+ *     As a special exception, the copyright holders of this library give you
+ *     permission to link this library with independent modules to produce an
+ *     executable, regardless of the license terms of these independent
+ *     modules, and to copy and distribute the resulting executable under terms
+ *     of your choice, provided that you also meet, for each linked independent
+ *     module, the terms and conditions of the license of that module. An
+ *     independent module is a module which is not derived from or based on
+ *     this library. If you modify this library, you may extend this exception
+ *     to your version of the library, but you are not obligated to do so. If
+ *     you do not wish to do so, delete this exception statement from your
+ *     version.
+ *
+ * Please refer to the file LICENSE for details.
+ */
+
+#include <jit/perf-map.h>
+#include <vm/die.h>
+
+#include <sys/types.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <stdio.h>
+
+static pthread_mutex_t perf_mutex = PTHREAD_MUTEX_INITIALIZER; 
+static FILE *perf_file;
+
+void perf_map_open(void)
+{
+	char filename[32];
+	pid_t pid;
+
+	pid = getpid();
+	sprintf(filename, "perf-%d.map", pid);
+
+	perf_file = fopen(filename, "w");
+	if (!perf_file)
+		die("fopen");
+}
+
+void perf_map_append(const char *symbol, unsigned long addr, unsigned long size)
+{
+	pthread_mutex_lock(&perf_mutex);
+	fprintf(perf_file, "%lx %lx %s\n", addr, size, symbol);
+	pthread_mutex_unlock(&perf_mutex);
+}

vm/jato.c

@@ -32,6 +32,7 @@
 #include <jit/cu-mapping.h>
 #include <jit/exception.h>
 #include <jit/compiler.h>
+#include <jit/perf-map.h>
 
 #ifdef USE_ZIP
 #define BCP_MESSAGE "<jar/zip files and directories separated by :>"
@@ -300,6 +301,8 @@ int main(int argc, char *argv[]) {
 
     exe_name = argv[0];
 
+    perf_map_open();
+
     setup_signal_handlers();
     init_cu_mapping();
     init_exceptions();