perf tools: Generalize event synthesizing routines

Because we will need it in 'perf top' to support userspace
symbols for existing threads.

Now we pass a callback that will receive the synthesized event
and then write it to the output file in 'perf record' and in the
upcoming patch for 'perf top' we will just immediatelly create
the in memory representation of threads and maps.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1256592199-9608-2-git-send-email-acme@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

tools/perf/Makefile

@@ -380,6 +380,7 @@ LIB_OBJS += util/alias.o
 LIB_OBJS += util/config.o
 LIB_OBJS += util/ctype.o
 LIB_OBJS += util/environment.o
+LIB_OBJS += util/event.o
 LIB_OBJS += util/exec_cmd.o
 LIB_OBJS += util/help.o
 LIB_OBJS += util/levenshtein.o

tools/perf/builtin-record.c

@@ -109,6 +109,12 @@ static void write_output(void *buf, size_t size)
 	}
 }
 
+static int process_synthesized_event(event_t *event)
+{
+	write_output(event, event->header.size);
+	return 0;
+}
+
 static void mmap_read(struct mmap_data *md)
 {
 	unsigned int head = mmap_read_head(md);
@@ -191,172 +197,6 @@ static void sig_atexit(void)
 	kill(getpid(), signr);
 }
 
-static pid_t pid_synthesize_comm_event(pid_t pid, int full)
-{
-	struct comm_event comm_ev;
-	char filename[PATH_MAX];
-	char bf[BUFSIZ];
-	FILE *fp;
-	size_t size = 0;
-	DIR *tasks;
-	struct dirent dirent, *next;
-	pid_t tgid = 0;
-
-	snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
-
-	fp = fopen(filename, "r");
-	if (fp == NULL) {
-out_race:	
-		/*
-		 * We raced with a task exiting - just return:
-		 */
-		if (verbose)
-			fprintf(stderr, "couldn't open %s\n", filename);
-		return 0;
-	}
-
-	memset(&comm_ev, 0, sizeof(comm_ev));
-	while (!comm_ev.comm[0] || !comm_ev.pid) {
-		if (fgets(bf, sizeof(bf), fp) == NULL)
-			goto out_failure;
-
-		if (memcmp(bf, "Name:", 5) == 0) {
-			char *name = bf + 5;
-			while (*name && isspace(*name))
-				++name;
-			size = strlen(name) - 1;
-			memcpy(comm_ev.comm, name, size++);
-		} else if (memcmp(bf, "Tgid:", 5) == 0) {
-			char *tgids = bf + 5;
-			while (*tgids && isspace(*tgids))
-				++tgids;
-			tgid = comm_ev.pid = atoi(tgids);
-		}
-	}
-
-	comm_ev.header.type = PERF_RECORD_COMM;
-	size = ALIGN(size, sizeof(u64));
-	comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
-
-	if (!full) {
-		comm_ev.tid = pid;
-
-		write_output(&comm_ev, comm_ev.header.size);
-		goto out_fclose;
-	}
-
-	snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
-
-	tasks = opendir(filename);
-	if (tasks == NULL)
-		goto out_race;
-
-	while (!readdir_r(tasks, &dirent, &next) && next) {
-		char *end;
-		pid = strtol(dirent.d_name, &end, 10);
-		if (*end)
-			continue;
-
-		comm_ev.tid = pid;
-
-		write_output(&comm_ev, comm_ev.header.size);
-	}
-	closedir(tasks);
-
-out_fclose:
-	fclose(fp);
-	return tgid;
-
-out_failure:
-	fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
-		filename);
-	exit(EXIT_FAILURE);
-}
-
-static void pid_synthesize_mmap_samples(pid_t pid, pid_t tgid)
-{
-	char filename[PATH_MAX];
-	FILE *fp;
-
-	snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
-
-	fp = fopen(filename, "r");
-	if (fp == NULL) {
-		/*
-		 * We raced with a task exiting - just return:
-		 */
-		if (verbose)
-			fprintf(stderr, "couldn't open %s\n", filename);
-		return;
-	}
-	while (1) {
-		char bf[BUFSIZ], *pbf = bf;
-		struct mmap_event mmap_ev = {
-			.header = { .type = PERF_RECORD_MMAP },
-		};
-		int n;
-		size_t size;
-		if (fgets(bf, sizeof(bf), fp) == NULL)
-			break;
-
-		/* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
-		n = hex2u64(pbf, &mmap_ev.start);
-		if (n < 0)
-			continue;
-		pbf += n + 1;
-		n = hex2u64(pbf, &mmap_ev.len);
-		if (n < 0)
-			continue;
-		pbf += n + 3;
-		if (*pbf == 'x') { /* vm_exec */
-			char *execname = strchr(bf, '/');
-
-			/* Catch VDSO */
-			if (execname == NULL)
-				execname = strstr(bf, "[vdso]");
-
-			if (execname == NULL)
-				continue;
-
-			size = strlen(execname);
-			execname[size - 1] = '\0'; /* Remove \n */
-			memcpy(mmap_ev.filename, execname, size);
-			size = ALIGN(size, sizeof(u64));
-			mmap_ev.len -= mmap_ev.start;
-			mmap_ev.header.size = (sizeof(mmap_ev) -
-					       (sizeof(mmap_ev.filename) - size));
-			mmap_ev.pid = tgid;
-			mmap_ev.tid = pid;
-
-			write_output(&mmap_ev, mmap_ev.header.size);
-		}
-	}
-
-	fclose(fp);
-}
-
-static void synthesize_all(void)
-{
-	DIR *proc;
-	struct dirent dirent, *next;
-
-	proc = opendir("/proc");
-
-	while (!readdir_r(proc, &dirent, &next) && next) {
-		char *end;
-		pid_t pid, tgid;
-
-		pid = strtol(dirent.d_name, &end, 10);
-		if (*end) /* only interested in proper numerical dirents */
-			continue;
-
-		tgid = pid_synthesize_comm_event(pid, 1);
-		pid_synthesize_mmap_samples(pid, tgid);
-	}
-
-	closedir(proc);
-}
-
 static int group_fd;
 
 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
@@ -608,11 +448,10 @@ static int __cmd_record(int argc, const char **argv)
 	if (file_new)
 		perf_header__write(header, output);
 
-	if (!system_wide) {
-		pid_t tgid = pid_synthesize_comm_event(pid, 0);
-		pid_synthesize_mmap_samples(pid, tgid);
-	} else
-		synthesize_all();
+	if (!system_wide)
+		event__synthesize_thread(pid, process_synthesized_event);
+	else
+		event__synthesize_threads(process_synthesized_event);
 
 	if (target_pid == -1 && argc) {
 		pid = fork();

tools/perf/util/event.c

+#include <linux/types.h>
+#include "event.h"
+#include "debug.h"
+#include "string.h"
+
+static pid_t event__synthesize_comm(pid_t pid, int full,
+				    int (*process)(event_t *event))
+{
+	event_t ev;
+	char filename[PATH_MAX];
+	char bf[BUFSIZ];
+	FILE *fp;
+	size_t size = 0;
+	DIR *tasks;
+	struct dirent dirent, *next;
+	pid_t tgid = 0;
+
+	snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
+
+	fp = fopen(filename, "r");
+	if (fp == NULL) {
+out_race:
+		/*
+		 * We raced with a task exiting - just return:
+		 */
+		pr_debug("couldn't open %s\n", filename);
+		return 0;
+	}
+
+	memset(&ev.comm, 0, sizeof(ev.comm));
+	while (!ev.comm.comm[0] || !ev.comm.pid) {
+		if (fgets(bf, sizeof(bf), fp) == NULL)
+			goto out_failure;
+
+		if (memcmp(bf, "Name:", 5) == 0) {
+			char *name = bf + 5;
+			while (*name && isspace(*name))
+				++name;
+			size = strlen(name) - 1;
+			memcpy(ev.comm.comm, name, size++);
+		} else if (memcmp(bf, "Tgid:", 5) == 0) {
+			char *tgids = bf + 5;
+			while (*tgids && isspace(*tgids))
+				++tgids;
+			tgid = ev.comm.pid = atoi(tgids);
+		}
+	}
+
+	ev.comm.header.type = PERF_RECORD_COMM;
+	size = ALIGN(size, sizeof(u64));
+	ev.comm.header.size = sizeof(ev.comm) - (sizeof(ev.comm.comm) - size);
+
+	if (!full) {
+		ev.comm.tid = pid;
+
+		process(&ev);
+		goto out_fclose;
+	}
+
+	snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
+
+	tasks = opendir(filename);
+	if (tasks == NULL)
+		goto out_race;
+
+	while (!readdir_r(tasks, &dirent, &next) && next) {
+		char *end;
+		pid = strtol(dirent.d_name, &end, 10);
+		if (*end)
+			continue;
+
+		ev.comm.tid = pid;
+
+		process(&ev);
+	}
+	closedir(tasks);
+
+out_fclose:
+	fclose(fp);
+	return tgid;
+
+out_failure:
+	pr_warning("couldn't get COMM and pgid, malformed %s\n", filename);
+	return -1;
+}
+
+static int event__synthesize_mmap_events(pid_t pid, pid_t tgid,
+					 int (*process)(event_t *event))
+{
+	char filename[PATH_MAX];
+	FILE *fp;
+
+	snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
+
+	fp = fopen(filename, "r");
+	if (fp == NULL) {
+		/*
+		 * We raced with a task exiting - just return:
+		 */
+		pr_debug("couldn't open %s\n", filename);
+		return -1;
+	}
+
+	while (1) {
+		char bf[BUFSIZ], *pbf = bf;
+		event_t ev = {
+			.header = { .type = PERF_RECORD_MMAP },
+		};
+		int n;
+		size_t size;
+		if (fgets(bf, sizeof(bf), fp) == NULL)
+			break;
+
+		/* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
+		n = hex2u64(pbf, &ev.mmap.start);
+		if (n < 0)
+			continue;
+		pbf += n + 1;
+		n = hex2u64(pbf, &ev.mmap.len);
+		if (n < 0)
+			continue;
+		pbf += n + 3;
+		if (*pbf == 'x') { /* vm_exec */
+			char *execname = strchr(bf, '/');
+
+			/* Catch VDSO */
+			if (execname == NULL)
+				execname = strstr(bf, "[vdso]");
+
+			if (execname == NULL)
+				continue;
+
+			size = strlen(execname);
+			execname[size - 1] = '\0'; /* Remove \n */
+			memcpy(ev.mmap.filename, execname, size);
+			size = ALIGN(size, sizeof(u64));
+			ev.mmap.len -= ev.mmap.start;
+			ev.mmap.header.size = (sizeof(ev.mmap) -
+					       (sizeof(ev.mmap.filename) - size));
+			ev.mmap.pid = tgid;
+			ev.mmap.tid = pid;
+
+			process(&ev);
+		}
+	}
+
+	fclose(fp);
+	return 0;
+}
+
+int event__synthesize_thread(pid_t pid, int (*process)(event_t *event))
+{
+	pid_t tgid = event__synthesize_comm(pid, 1, process);
+	if (tgid == -1)
+		return -1;
+	return event__synthesize_mmap_events(pid, tgid, process);
+}
+
+void event__synthesize_threads(int (*process)(event_t *event))
+{
+	DIR *proc;
+	struct dirent dirent, *next;
+
+	proc = opendir("/proc");
+
+	while (!readdir_r(proc, &dirent, &next) && next) {
+		char *end;
+		pid_t pid = strtol(dirent.d_name, &end, 10);
+
+		if (*end) /* only interested in proper numerical dirents */
+			continue;
+
+		event__synthesize_thread(pid, process);
+	}
+
+	closedir(proc);
+}

tools/perf/util/event.h

@@ -111,4 +111,7 @@ struct map *map__clone(struct map *self);
 int map__overlap(struct map *l, struct map *r);
 size_t map__fprintf(struct map *self, FILE *fp);
 
+int event__synthesize_thread(pid_t pid, int (*process)(event_t *event));
+void event__synthesize_threads(int (*process)(event_t *event));
+
 #endif /* __PERF_RECORD_H */