Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

The SmartMedia FTL code depends on new kfifo bits from 2.6.33

1 files changed, 95 insertions, 48 deletions

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 4decbd14eaed..265425322734 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -123,7 +123,8 @@ static void write_event(event_t *buf, size_t size)
 	write_output(buf, size);
 }
 
-static int process_synthesized_event(event_t *event)
+static int process_synthesized_event(event_t *event,
+				     struct perf_session *self __used)
 {
 	write_event(event, event->header.size);
 	return 0;
@@ -277,7 +278,7 @@ static void create_counter(int counter, int cpu, pid_t pid)
 
 	attr->mmap		= track;
 	attr->comm		= track;
-	attr->inherit		= (cpu < 0) && inherit;
+	attr->inherit		= inherit;
 	attr->disabled		= 1;
 
 try_again:
@@ -409,6 +410,9 @@ static int __cmd_record(int argc, const char **argv)
 	int flags;
 	int err;
 	unsigned long waking = 0;
+	int child_ready_pipe[2], go_pipe[2];
+	const bool forks = target_pid == -1 && argc > 0;
+	char buf;
 
 	page_size = sysconf(_SC_PAGE_SIZE);
 	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
@@ -419,11 +423,25 @@ static int __cmd_record(int argc, const char **argv)
 	signal(SIGCHLD, sig_handler);
 	signal(SIGINT, sig_handler);
 
+	if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
+		perror("failed to create pipes");
+		exit(-1);
+	}
+
 	if (!stat(output_name, &st) && st.st_size) {
-		if (!force && !append_file) {
-			fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
-					output_name);
-			exit(-1);
+		if (!force) {
+			if (!append_file) {
+				pr_err("Error, output file %s exists, use -A "
+				       "to append or -f to overwrite.\n",
+				       output_name);
+				exit(-1);
+			}
+		} else {
+			char oldname[PATH_MAX];
+			snprintf(oldname, sizeof(oldname), "%s.old",
+				 output_name);
+			unlink(oldname);
+			rename(output_name, oldname);
 		}
 	} else {
 		append_file = 0;
@@ -466,56 +484,79 @@ static int __cmd_record(int argc, const char **argv)
 
 	atexit(atexit_header);
 
-	if (!system_wide) {
-		pid = target_pid;
-		if (pid == -1)
-			pid = getpid();
-
-		open_counters(profile_cpu, pid);
-	} else {
-		if (profile_cpu != -1) {
-			open_counters(profile_cpu, target_pid);
-		} else {
-			for (i = 0; i < nr_cpus; i++)
-				open_counters(i, target_pid);
+	if (forks) {
+		pid = fork();
+		if (pid < 0) {
+			perror("failed to fork");
+			exit(-1);
 		}
-	}
 
-	if (file_new) {
-		err = perf_header__write(&session->header, output, false);
-		if (err < 0)
-			return err;
-	}
+		if (!pid) {
+			close(child_ready_pipe[0]);
+			close(go_pipe[1]);
+			fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
 
-	if (!system_wide)
-		event__synthesize_thread(pid, process_synthesized_event);
-	else
-		event__synthesize_threads(process_synthesized_event);
+			/*
+			 * Do a dummy execvp to get the PLT entry resolved,
+			 * so we avoid the resolver overhead on the real
+			 * execvp call.
+			 */
+			execvp("", (char **)argv);
 
-	if (target_pid == -1 && argc) {
-		pid = fork();
-		if (pid < 0)
-			die("failed to fork");
+			/*
+			 * Tell the parent we're ready to go
+			 */
+			close(child_ready_pipe[1]);
 
-		if (!pid) {
-			if (execvp(argv[0], (char **)argv)) {
-				perror(argv[0]);
-				exit(-1);
-			}
-		} else {
 			/*
-			 * Wait a bit for the execv'ed child to appear
-			 * and be updated in /proc
-			 * FIXME: Do you know a less heuristical solution?
+			 * Wait until the parent tells us to go.
 			 */
-			usleep(1000);
-			event__synthesize_thread(pid,
-						 process_synthesized_event);
+			if (read(go_pipe[0], &buf, 1) == -1)
+				perror("unable to read pipe");
+
+			execvp(argv[0], (char **)argv);
+
+			perror(argv[0]);
+			exit(-1);
 		}
 
 		child_pid = pid;
+
+		if (!system_wide)
+			target_pid = pid;
+
+		close(child_ready_pipe[1]);
+		close(go_pipe[0]);
+		/*
+		 * wait for child to settle
+		 */
+		if (read(child_ready_pipe[0], &buf, 1) == -1) {
+			perror("unable to read pipe");
+			exit(-1);
+		}
+		close(child_ready_pipe[0]);
+	}
+
+
+	if ((!system_wide && !inherit) || profile_cpu != -1) {
+		open_counters(profile_cpu, target_pid);
+	} else {
+		for (i = 0; i < nr_cpus; i++)
+			open_counters(i, target_pid);
 	}
 
+	if (file_new) {
+		err = perf_header__write(&session->header, output, false);
+		if (err < 0)
+			return err;
+	}
+
+	if (!system_wide && profile_cpu == -1)
+		event__synthesize_thread(pid, process_synthesized_event,
+					 session);
+	else
+		event__synthesize_threads(process_synthesized_event, session);
+
 	if (realtime_prio) {
 		struct sched_param param;
 
@@ -526,6 +567,12 @@ static int __cmd_record(int argc, const char **argv)
 		}
 	}
 
+	/*
+	 * Let the child rip
+	 */
+	if (forks)
+		close(go_pipe[1]);
+
 	for (;;) {
 		int hits = samples;
 
@@ -620,13 +667,13 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
 {
 	int counter;
 
-	symbol__init(0);
-
 	argc = parse_options(argc, argv, options, record_usage,
-		PARSE_OPT_STOP_AT_NON_OPTION);
-	if (!argc && target_pid == -1 && !system_wide)
+			    PARSE_OPT_STOP_AT_NON_OPTION);
+	if (!argc && target_pid == -1 && !system_wide && profile_cpu == -1)
 		usage_with_options(record_usage, options);
 
+	symbol__init();
+
 	if (!nr_counters) {
 		nr_counters	= 1;
 		attrs[0].type	= PERF_TYPE_HARDWARE;