Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

  * Convert callchain children list to rbtree, greatly reducing the time
    taken for callchain processing, from Namhyung Kim.

  * Add --max-stack option to limit callchain stack scan in 'top' and 'report',
    improving callchain processing when reducing the stack depth is an option,
    from Waiman Long.

  * Compare dso's also when comparing symbols, to avoid grouping together
    symbols with the same name but on different DSOs, fix from Namhyung Kim.

  * 'perf trace' now can can use a 'perf probe' wannabe tracepoint to hook into
    the userspace -> kernel pathname copy so that it can map fds to pathnames
    without reading /proc/pid/fd/ symlinks. From Arnaldo Carvalho de Melo.

  * 'perf trace' now emits hints as to why tracing is not possible, helping the
    user to setup the system to allow tracing in the desired permission
    granularity, telling if the problem is due to debugfs not being mounted or
    with not enough permission for !root, /proc/sys/kernel/perf_event_paranoit
    value, etc. From Arnaldo Carvalho de Melo.

  * Add missing 'mmap2' in evsel debug print, from Adrian Hunter.

  * Add missing decrement in id sample parsing, not a fix per se, just to
    avoid a problem whem somebody adds another field, from Adrian Hunter.

  * Improve write_output error message in 'perf record', from Adrian Hunter.

  * Add missing sample flush for piped events, fix from Adrian Hunter.

  * Add missing members to perf_event__attr_swap(), fix from Adrian Hunter.

  * Assorted fixes for 32-bit build, from Adrian Hunter

  * Print addr by default for BTS in 'perf script', from Adrian Juntmer

  * Separating data file properties from session, code reorganization from
    Jiri Olsa.

  * Show error in 'perf list' if tracepoints not available, from Pekka Enberg.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 126 insertions, 70 deletions

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index d0f91fe755a3d..fa620bc1db69b 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -951,7 +951,10 @@ fail:
 
 struct trace {
 	struct perf_tool	tool;
-	int			audit_machine;
+	struct {
+		int		machine;
+		int		open_id;
+	}			audit;
 	struct {
 		int		max;
 		struct syscall  *table;
@@ -965,40 +968,24 @@ struct trace {
 	struct strlist		*ev_qualifier;
 	bool			not_ev_qualifier;
 	bool			live;
+	const char 		*last_vfs_getname;
 	struct intlist		*tid_list;
 	struct intlist		*pid_list;
 	bool			sched;
 	bool			multiple_threads;
 	bool			summary;
 	bool			show_comm;
+	bool			show_tool_stats;
 	double			duration_filter;
 	double			runtime_ms;
+	struct {
+		u64		vfs_getname, proc_getname;
+	} stats;
 };
 
-static int thread__read_fd_path(struct thread *thread, int fd)
+static int trace__set_fd_pathname(struct thread *thread, int fd, const char *pathname)
 {
 	struct thread_trace *ttrace = thread->priv;
-	char linkname[PATH_MAX], pathname[PATH_MAX];
-	struct stat st;
-	int ret;
-
-	if (thread->pid_ == thread->tid) {
-		scnprintf(linkname, sizeof(linkname),
-			  "/proc/%d/fd/%d", thread->pid_, fd);
-	} else {
-		scnprintf(linkname, sizeof(linkname),
-			  "/proc/%d/task/%d/fd/%d", thread->pid_, thread->tid, fd);
-	}
-
-	if (lstat(linkname, &st) < 0 || st.st_size + 1 > (off_t)sizeof(pathname))
-		return -1;
-
-	ret = readlink(linkname, pathname, sizeof(pathname));
-
-	if (ret < 0 || ret > st.st_size)
-		return -1;
-
-	pathname[ret] = '\0';
 
 	if (fd > ttrace->paths.max) {
 		char **npath = realloc(ttrace->paths.table, (fd + 1) * sizeof(char *));
@@ -1022,7 +1009,34 @@ static int thread__read_fd_path(struct thread *thread, int fd)
 	return ttrace->paths.table[fd] != NULL ? 0 : -1;
 }
 
-static const char *thread__fd_path(struct thread *thread, int fd, bool live)
+static int thread__read_fd_path(struct thread *thread, int fd)
+{
+	char linkname[PATH_MAX], pathname[PATH_MAX];
+	struct stat st;
+	int ret;
+
+	if (thread->pid_ == thread->tid) {
+		scnprintf(linkname, sizeof(linkname),
+			  "/proc/%d/fd/%d", thread->pid_, fd);
+	} else {
+		scnprintf(linkname, sizeof(linkname),
+			  "/proc/%d/task/%d/fd/%d", thread->pid_, thread->tid, fd);
+	}
+
+	if (lstat(linkname, &st) < 0 || st.st_size + 1 > (off_t)sizeof(pathname))
+		return -1;
+
+	ret = readlink(linkname, pathname, sizeof(pathname));
+
+	if (ret < 0 || ret > st.st_size)
+		return -1;
+
+	pathname[ret] = '\0';
+	return trace__set_fd_pathname(thread, fd, pathname);
+}
+
+static const char *thread__fd_path(struct thread *thread, int fd,
+				   struct trace *trace)
 {
 	struct thread_trace *ttrace = thread->priv;
 
@@ -1032,9 +1046,13 @@ static const char *thread__fd_path(struct thread *thread, int fd, bool live)
 	if (fd < 0)
 		return NULL;
 
-	if ((fd > ttrace->paths.max || ttrace->paths.table[fd] == NULL) &&
-	    (!live || thread__read_fd_path(thread, fd)))
-		return NULL;
+	if ((fd > ttrace->paths.max || ttrace->paths.table[fd] == NULL))
+		if (!trace->live)
+			return NULL;
+		++trace->stats.proc_getname;
+		if (thread__read_fd_path(thread, fd)) {
+			return NULL;
+	}
 
 	return ttrace->paths.table[fd];
 }
@@ -1044,7 +1062,7 @@ static size_t syscall_arg__scnprintf_fd(char *bf, size_t size,
 {
 	int fd = arg->val;
 	size_t printed = scnprintf(bf, size, "%d", fd);
-	const char *path = thread__fd_path(arg->thread, fd, arg->trace->live);
+	const char *path = thread__fd_path(arg->thread, fd, arg->trace);
 
 	if (path)
 		printed += scnprintf(bf + printed, size - printed, "<%s>", path);
@@ -1080,10 +1098,12 @@ static size_t trace__fprintf_tstamp(struct trace *trace, u64 tstamp, FILE *fp)
 }
 
 static bool done = false;
+static bool interrupted = false;
 
-static void sig_handler(int sig __maybe_unused)
+static void sig_handler(int sig)
 {
 	done = true;
+	interrupted = sig == SIGINT;
 }
 
 static size_t trace__fprintf_entry_head(struct trace *trace, struct thread *thread,
@@ -1181,7 +1201,7 @@ static int trace__read_syscall_info(struct trace *trace, int id)
 {
 	char tp_name[128];
 	struct syscall *sc;
-	const char *name = audit_syscall_to_name(id, trace->audit_machine);
+	const char *name = audit_syscall_to_name(id, trace->audit.machine);
 
 	if (name == NULL)
 		return -1;
@@ -1445,6 +1465,12 @@ static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel,
 
 	ret = perf_evsel__intval(evsel, sample, "ret");
 
+	if (id == trace->audit.open_id && ret >= 0 && trace->last_vfs_getname) {
+		trace__set_fd_pathname(thread, ret, trace->last_vfs_getname);
+		trace->last_vfs_getname = NULL;
+		++trace->stats.vfs_getname;
+	}
+
 	ttrace = thread->priv;
 
 	ttrace->exit_time = sample->time;
@@ -1489,6 +1515,13 @@ out:
 	return 0;
 }
 
+static int trace__vfs_getname(struct trace *trace, struct perf_evsel *evsel,
+			      struct perf_sample *sample)
+{
+	trace->last_vfs_getname = perf_evsel__rawptr(evsel, sample, "pathname");
+	return 0;
+}
+
 static int trace__sched_stat_runtime(struct trace *trace, struct perf_evsel *evsel,
 				     struct perf_sample *sample)
 {
@@ -1611,6 +1644,22 @@ static int trace__record(int argc, const char **argv)
 
 static size_t trace__fprintf_thread_summary(struct trace *trace, FILE *fp);
 
+static void perf_evlist__add_vfs_getname(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = perf_evsel__newtp("probe", "vfs_getname",
+						     evlist->nr_entries);
+	if (evsel == NULL)
+		return;
+
+	if (perf_evsel__field(evsel, "pathname") == NULL) {
+		perf_evsel__delete(evsel);
+		return;
+	}
+
+	evsel->handler.func = trace__vfs_getname;
+	perf_evlist__add(evlist, evsel);
+}
+
 static int trace__run(struct trace *trace, int argc, const char **argv)
 {
 	struct perf_evlist *evlist = perf_evlist__new();
@@ -1630,6 +1679,8 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 		perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_exit", trace__sys_exit))
 		goto out_error_tp;
 
+	perf_evlist__add_vfs_getname(evlist);
+
 	if (trace->sched &&
 		perf_evlist__add_newtp(evlist, "sched", "sched_stat_runtime",
 				trace__sched_stat_runtime))
@@ -1662,10 +1713,8 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 	}
 
 	err = perf_evlist__open(evlist);
-	if (err < 0) {
-		fprintf(trace->output, "Couldn't create the events: %s\n", strerror(errno));
-		goto out_delete_maps;
-	}
+	if (err < 0)
+		goto out_error_open;
 
 	err = perf_evlist__mmap(evlist, UINT_MAX, false);
 	if (err < 0) {
@@ -1722,26 +1771,35 @@ again:
 			handler = evsel->handler.func;
 			handler(trace, evsel, &sample);
 
-			if (done)
-				goto out_unmap_evlist;
+			if (interrupted)
+				goto out_disable;
 		}
 	}
 
 	if (trace->nr_events == before) {
-		if (done)
-			goto out_unmap_evlist;
+		int timeout = done ? 100 : -1;
 
-		poll(evlist->pollfd, evlist->nr_fds, -1);
+		if (poll(evlist->pollfd, evlist->nr_fds, timeout) > 0)
+			goto again;
+	} else {
+		goto again;
 	}
 
-	if (done)
-		perf_evlist__disable(evlist);
+out_disable:
+	perf_evlist__disable(evlist);
 
-	goto again;
+	if (!err) {
+		if (trace->summary)
+			trace__fprintf_thread_summary(trace, trace->output);
 
-out_unmap_evlist:
-	if (!err && trace->summary)
-		trace__fprintf_thread_summary(trace, trace->output);
+		if (trace->show_tool_stats) {
+			fprintf(trace->output, "Stats:\n "
+					       " vfs_getname : %" PRIu64 "\n"
+					       " proc_getname: %" PRIu64 "\n",
+				trace->stats.vfs_getname,
+				trace->stats.proc_getname);
+		}
+	}
 
 	perf_evlist__munmap(evlist);
 out_close_evlist:
@@ -1753,38 +1811,33 @@ out_delete_evlist:
 out:
 	trace->live = false;
 	return err;
+{
+	char errbuf[BUFSIZ];
+
 out_error_tp:
-	switch(errno) {
-	case ENOENT:
-		fputs("Error:\tUnable to find debugfs\n"
-		      "Hint:\tWas your kernel was compiled with debugfs support?\n"
-		      "Hint:\tIs the debugfs filesystem mounted?\n"
-		      "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'\n",
-		      trace->output);
-		break;
-	case EACCES:
-		fprintf(trace->output,
-			"Error:\tNo permissions to read %s/tracing/events/raw_syscalls\n"
-			"Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
-			debugfs_mountpoint, debugfs_mountpoint);
-		break;
-	default: {
-		char bf[256];
-		fprintf(trace->output, "Can't trace: %s\n",
-			strerror_r(errno, bf, sizeof(bf)));
-	}
-		break;
-	}
+	perf_evlist__strerror_tp(evlist, errno, errbuf, sizeof(errbuf));
+	goto out_error;
+
+out_error_open:
+	perf_evlist__strerror_open(evlist, errno, errbuf, sizeof(errbuf));
+
+out_error:
+	fprintf(trace->output, "%s\n", errbuf);
 	goto out_delete_evlist;
 }
+}
 
 static int trace__replay(struct trace *trace)
 {
 	const struct perf_evsel_str_handler handlers[] = {
 		{ "raw_syscalls:sys_enter",  trace__sys_enter, },
 		{ "raw_syscalls:sys_exit",   trace__sys_exit, },
+		{ "probe:vfs_getname",	     trace__vfs_getname, },
+	};
+	struct perf_data_file file = {
+		.path  = input_name,
+		.mode  = PERF_DATA_MODE_READ,
 	};
-
 	struct perf_session *session;
 	int err = -1;
 
@@ -1807,8 +1860,7 @@ static int trace__replay(struct trace *trace)
 	if (symbol__init() < 0)
 		return -1;
 
-	session = perf_session__new(input_name, O_RDONLY, 0, false,
-				    &trace->tool);
+	session = perf_session__new(&file, false, &trace->tool);
 	if (session == NULL)
 		return -ENOMEM;
 
@@ -1992,7 +2044,10 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
 		NULL
 	};
 	struct trace trace = {
-		.audit_machine = audit_detect_machine(),
+		.audit = {
+			.machine = audit_detect_machine(),
+			.open_id = audit_name_to_syscall("open", trace.audit.machine),
+		},
 		.syscalls = {
 			. max = -1,
 		},
@@ -2014,6 +2069,7 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
 	const struct option trace_options[] = {
 	OPT_BOOLEAN(0, "comm", &trace.show_comm,
 		    "show the thread COMM next to its id"),
+	OPT_BOOLEAN(0, "tool_stats", &trace.show_tool_stats, "show tool stats"),
 	OPT_STRING('e', "expr", &ev_qualifier_str, "expr",
 		    "list of events to trace"),
 	OPT_STRING('o', "output", &output_name, "file", "output file name"),