perf tools: Introduce per user view

The new --uid command line option will show only the tasks for a given
user, using the proc interface to figure out the existing tasks.

Kernel work is needed to close races at startup, but this should already
be useful in many use cases.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-bdnspm000gw2l984a2t53o8z@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-record.txt

@@ -58,6 +58,10 @@ OPTIONS
 --tid=::
         Record events on existing thread ID.
 
+-u::
+--uid=::
+        Record events in threads owned by uid. Name or number.
+
 -r::
 --realtime=::
 	Collect data with this RT SCHED_FIFO priority.

tools/perf/Documentation/perf-top.txt

@@ -78,6 +78,10 @@ Default is to monitor all CPUS.
 --tid=<tid>::
         Profile events on existing thread ID.
 
+-u::
+--uid=::
+        Record events in threads owned by uid. Name or number.
+
 -r <priority>::
 --realtime=<priority>::
 	Collect data with this RT SCHED_FIFO priority.

tools/perf/builtin-record.c

@@ -44,6 +44,7 @@ struct perf_record {
 	struct perf_evlist	*evlist;
 	struct perf_session	*session;
 	const char		*progname;
+	const char		*uid_str;
 	int			output;
 	unsigned int		page_size;
 	int			realtime_prio;
@@ -727,6 +728,7 @@ const struct option record_options[] = {
 	OPT_CALLBACK('G', "cgroup", &record.evlist, "name",
 		     "monitor event in cgroup name only",
 		     parse_cgroups),
+	OPT_STRING('u', "uid", &record.uid_str, "user", "user to profile"),
 	OPT_END()
 };
 
@@ -748,7 +750,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
 	argc = parse_options(argc, argv, record_options, record_usage,
 			    PARSE_OPT_STOP_AT_NON_OPTION);
 	if (!argc && rec->opts.target_pid == -1 && rec->opts.target_tid == -1 &&
-		!rec->opts.system_wide && !rec->opts.cpu_list)
+		!rec->opts.system_wide && !rec->opts.cpu_list && !rec->uid_str)
 		usage_with_options(record_usage, record_options);
 
 	if (rec->force && rec->append_file) {
@@ -788,11 +790,17 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
 		goto out_symbol_exit;
 	}
 
+	rec->opts.uid = parse_target_uid(rec->uid_str, rec->opts.target_tid,
+					 rec->opts.target_pid);
+	if (rec->uid_str != NULL && rec->opts.uid == UINT_MAX - 1)
+		goto out_free_fd;
+
 	if (rec->opts.target_pid != -1)
 		rec->opts.target_tid = rec->opts.target_pid;
 
 	if (perf_evlist__create_maps(evsel_list, rec->opts.target_pid,
-				     rec->opts.target_tid, rec->opts.cpu_list) < 0)
+				     rec->opts.target_tid, rec->opts.uid,
+				     rec->opts.cpu_list) < 0)
 		usage_with_options(record_usage, record_options);
 
 	list_for_each_entry(pos, &evsel_list->entries, node) {

tools/perf/builtin-stat.c

@@ -1201,7 +1201,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used)
 	if (target_pid != -1)
 		target_tid = target_pid;
 
-	evsel_list->threads = thread_map__new(target_pid, target_tid);
+	evsel_list->threads = thread_map__new(target_pid, target_tid, UINT_MAX);
 	if (evsel_list->threads == NULL) {
 		pr_err("Problems finding threads of monitor\n");
 		usage_with_options(stat_usage, options);

tools/perf/builtin-test.c

@@ -276,7 +276,7 @@ static int test__open_syscall_event(void)
 		return -1;
 	}
 
-	threads = thread_map__new(-1, getpid());
+	threads = thread_map__new(-1, getpid(), UINT_MAX);
 	if (threads == NULL) {
 		pr_debug("thread_map__new\n");
 		return -1;
@@ -342,7 +342,7 @@ static int test__open_syscall_event_on_all_cpus(void)
 		return -1;
 	}
 
-	threads = thread_map__new(-1, getpid());
+	threads = thread_map__new(-1, getpid(), UINT_MAX);
 	if (threads == NULL) {
 		pr_debug("thread_map__new\n");
 		return -1;
@@ -490,7 +490,7 @@ static int test__basic_mmap(void)
 		expected_nr_events[i] = random() % 257;
 	}
 
-	threads = thread_map__new(-1, getpid());
+	threads = thread_map__new(-1, getpid(), UINT_MAX);
 	if (threads == NULL) {
 		pr_debug("thread_map__new\n");
 		return -1;
@@ -1054,7 +1054,7 @@ static int test__PERF_RECORD(void)
 	 * we're monitoring, the one forked there.
 	 */
 	err = perf_evlist__create_maps(evlist, opts.target_pid,
-				       opts.target_tid, opts.cpu_list);
+				       opts.target_tid, UINT_MAX, opts.cpu_list);
 	if (err < 0) {
 		pr_debug("Not enough memory to create thread/cpu maps\n");
 		goto out_delete_evlist;

tools/perf/builtin-top.c

@@ -64,7 +64,6 @@
 #include <linux/unistd.h>
 #include <linux/types.h>
 
-
 void get_term_dimensions(struct winsize *ws)
 {
 	char *s = getenv("LINES");
@@ -537,10 +536,20 @@ static void perf_top__sort_new_samples(void *arg)
 
 static void *display_thread_tui(void *arg)
 {
+	struct perf_evsel *pos;
 	struct perf_top *top = arg;
 	const char *help = "For a higher level overview, try: perf top --sort comm,dso";
 
 	perf_top__sort_new_samples(top);
+
+	/*
+	 * Initialize the uid_filter_str, in the future the TUI will allow
+	 * Zooming in/out UIDs. For now juse use whatever the user passed
+	 * via --uid.
+	 */
+	list_for_each_entry(pos, &top->evlist->entries, node)
+		pos->hists.uid_filter_str = top->uid_str;
+
 	perf_evlist__tui_browse_hists(top->evlist, help,
 				      perf_top__sort_new_samples,
 				      top, top->delay_secs);
@@ -949,7 +958,7 @@ static int __cmd_top(struct perf_top *top)
 	if (ret)
 		goto out_delete;
 
-	if (top->target_tid != -1)
+	if (top->target_tid != -1 || top->uid != UINT_MAX)
 		perf_event__synthesize_thread_map(&top->tool, top->evlist->threads,
 						  perf_event__process,
 						  &top->session->host_machine);
@@ -1089,6 +1098,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
 		.delay_secs	     = 2,
 		.target_pid	     = -1,
 		.target_tid	     = -1,
+		.uid		     = UINT_MAX,
 		.freq		     = 1000, /* 1 KHz */
 		.sample_id_all_avail = true,
 		.mmap_pages	     = 128,
@@ -1162,6 +1172,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
 		    "Display raw encoding of assembly instructions (default)"),
 	OPT_STRING('M', "disassembler-style", &disassembler_style, "disassembler style",
 		   "Specify disassembler style (e.g. -M intel for intel syntax)"),
+	OPT_STRING('u', "uid", &top.uid_str, "user", "user to profile"),
 	OPT_END()
 	};
 
@@ -1187,6 +1198,10 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
 
 	setup_browser(false);
 
+	top.uid = parse_target_uid(top.uid_str, top.target_tid, top.target_pid);
+	if (top.uid_str != NULL && top.uid == UINT_MAX - 1)
+		goto out_delete_evlist;
+
 	/* CPU and PID are mutually exclusive */
 	if (top.target_tid > 0 && top.cpu_list) {
 		printf("WARNING: PID switch overriding CPU\n");
@@ -1198,7 +1213,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
 		top.target_tid = top.target_pid;
 
 	if (perf_evlist__create_maps(top.evlist, top.target_pid,
-				     top.target_tid, top.cpu_list) < 0)
+				     top.target_tid, top.uid, top.cpu_list) < 0)
 		usage_with_options(top_usage, options);
 
 	if (!top.evlist->nr_entries &&
@@ -1262,6 +1277,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
 
 	status = __cmd_top(&top);
 
+out_delete_evlist:
 	perf_evlist__delete(top.evlist);
 
 	return status;

tools/perf/perf.h

@@ -188,6 +188,7 @@ void pthread__unblock_sigwinch(void);
 struct perf_record_opts {
 	pid_t	     target_pid;
 	pid_t	     target_tid;
+	uid_t	     uid;
 	bool	     call_graph;
 	bool	     group;
 	bool	     inherit_stat;

tools/perf/util/evlist.c

@@ -594,14 +594,14 @@ int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
 }
 
 int perf_evlist__create_maps(struct perf_evlist *evlist, pid_t target_pid,
-			     pid_t target_tid, const char *cpu_list)
+			     pid_t target_tid, uid_t uid, const char *cpu_list)
 {
-	evlist->threads = thread_map__new(target_pid, target_tid);
+	evlist->threads = thread_map__new(target_pid, target_tid, uid);
 
 	if (evlist->threads == NULL)
 		return -1;
 
-	if (cpu_list == NULL && target_tid != -1)
+	if (uid != UINT_MAX || (cpu_list == NULL && target_tid != -1))
 		evlist->cpus = cpu_map__dummy_new();
 	else
 		evlist->cpus = cpu_map__new(cpu_list);

tools/perf/util/evlist.h

@@ -107,7 +107,7 @@ static inline void perf_evlist__set_maps(struct perf_evlist *evlist,
 }
 
 int perf_evlist__create_maps(struct perf_evlist *evlist, pid_t target_pid,
-			     pid_t target_tid, const char *cpu_list);
+			     pid_t tid, uid_t uid, const char *cpu_list);
 void perf_evlist__delete_maps(struct perf_evlist *evlist);
 int perf_evlist__set_filters(struct perf_evlist *evlist);
 

tools/perf/util/hist.h

@@ -55,6 +55,7 @@ struct hists {
 	u64			nr_entries;
 	const struct thread	*thread_filter;
 	const struct dso	*dso_filter;
+	const char		*uid_filter_str;
 	pthread_mutex_t		lock;
 	struct events_stats	stats;
 	u64			event_stream;

tools/perf/util/python.c

@@ -425,14 +425,14 @@ struct pyrf_thread_map {
 static int pyrf_thread_map__init(struct pyrf_thread_map *pthreads,
 				 PyObject *args, PyObject *kwargs)
 {
-	static char *kwlist[] = { "pid", "tid", NULL };
-	int pid = -1, tid = -1;
+	static char *kwlist[] = { "pid", "tid", "uid", NULL };
+	int pid = -1, tid = -1, uid = UINT_MAX;
 
-	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|ii",
-					 kwlist, &pid, &tid))
+	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|iii",
+					 kwlist, &pid, &tid, &uid))
 		return -1;
 
-	pthreads->threads = thread_map__new(pid, tid);
+	pthreads->threads = thread_map__new(pid, tid, uid);
 	if (pthreads->threads == NULL)
 		return -1;
 	return 0;

tools/perf/util/thread_map.c

@@ -1,6 +1,11 @@
 #include <dirent.h>
+#include <limits.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
 #include "thread_map.h"
 
 /* Skip "." and ".." directories */
@@ -23,7 +28,7 @@ struct thread_map *thread_map__new_by_pid(pid_t pid)
 	sprintf(name, "/proc/%d/task", pid);
 	items = scandir(name, &namelist, filter, NULL);
 	if (items <= 0)
-                return NULL;
+		return NULL;
 
 	threads = malloc(sizeof(*threads) + sizeof(pid_t) * items);
 	if (threads != NULL) {
@@ -51,10 +56,99 @@ struct thread_map *thread_map__new_by_tid(pid_t tid)
 	return threads;
 }
 
-struct thread_map *thread_map__new(pid_t pid, pid_t tid)
+struct thread_map *thread_map__new_by_uid(uid_t uid)
+{
+	DIR *proc;
+	int max_threads = 32, items, i;
+	char path[256];
+	struct dirent dirent, *next, **namelist = NULL;
+	struct thread_map *threads = malloc(sizeof(*threads) +
+					    max_threads * sizeof(pid_t));
+	if (threads == NULL)
+		goto out;
+
+	proc = opendir("/proc");
+	if (proc == NULL)
+		goto out_free_threads;
+
+	threads->nr = 0;
+
+	while (!readdir_r(proc, &dirent, &next) && next) {
+		char *end;
+		bool grow = false;
+		struct stat st;
+		pid_t pid = strtol(dirent.d_name, &end, 10);
+
+		if (*end) /* only interested in proper numerical dirents */
+			continue;
+
+		snprintf(path, sizeof(path), "/proc/%s", dirent.d_name);
+
+		if (stat(path, &st) != 0)
+			continue;
+
+		if (st.st_uid != uid)
+			continue;
+
+		snprintf(path, sizeof(path), "/proc/%d/task", pid);
+		items = scandir(path, &namelist, filter, NULL);
+		if (items <= 0)
+			goto out_free_closedir;
+
+		while (threads->nr + items >= max_threads) {
+			max_threads *= 2;
+			grow = true;
+		}
+
+		if (grow) {
+			struct thread_map *tmp;
+
+			tmp = realloc(threads, (sizeof(*threads) +
+						max_threads * sizeof(pid_t)));
+			if (tmp == NULL)
+				goto out_free_namelist;
+
+			threads = tmp;
+		}
+
+		for (i = 0; i < items; i++)
+			threads->map[threads->nr + i] = atoi(namelist[i]->d_name);
+
+		for (i = 0; i < items; i++)
+			free(namelist[i]);
+		free(namelist);
+
+		threads->nr += items;
+	}
+
+out_closedir:
+	closedir(proc);
+out:
+	return threads;
+
+out_free_threads:
+	free(threads);
+	return NULL;
+
+out_free_namelist:
+	for (i = 0; i < items; i++)
+		free(namelist[i]);
+	free(namelist);
+
+out_free_closedir:
+	free(threads);
+	threads = NULL;
+	goto out_closedir;
+}
+
+struct thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid)
 {
 	if (pid != -1)
 		return thread_map__new_by_pid(pid);
+
+	if (tid == -1 && uid != UINT_MAX)
+		return thread_map__new_by_uid(uid);
+
 	return thread_map__new_by_tid(tid);
 }
 

tools/perf/util/thread_map.h

@@ -11,7 +11,8 @@ struct thread_map {
 
 struct thread_map *thread_map__new_by_pid(pid_t pid);
 struct thread_map *thread_map__new_by_tid(pid_t tid);
-struct thread_map *thread_map__new(pid_t pid, pid_t tid);
+struct thread_map *thread_map__new_by_uid(uid_t uid);
+struct thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid);
 void thread_map__delete(struct thread_map *threads);
 
 size_t thread_map__fprintf(struct thread_map *threads, FILE *fp);

tools/perf/util/top.c

@@ -75,6 +75,9 @@ size_t perf_top__header_snprintf(struct perf_top *top, char *bf, size_t size)
 	else if (top->target_tid != -1)
 		ret += SNPRINTF(bf + ret, size - ret, " (target_tid: %d",
 				top->target_tid);
+	else if (top->uid_str != NULL)
+		ret += SNPRINTF(bf + ret, size - ret, " (uid: %s",
+				top->uid_str);
 	else
 		ret += SNPRINTF(bf + ret, size - ret, " (all");