perf_counter: tools: Expand the COMM,MMAP event synthesizer

Include code to pre-construct mappings based on /proc,
on system wide recording.

Fix the existing code to properly fill out ->pid and ->tid.

The PID should be the Thread Group ID (PIDTYPE_PID of task->group_leader)
The TID should be the Thread ID (PIDTYPE_PID of task)

Furthermore, change the default sorting of report to comm,dso for a
better quick overview.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 64 insertions, 20 deletions

diff --git a/Documentation/perf_counter/builtin-record.c b/Documentation/perf_counter/builtin-record.c
index 9c151ded22fa..810fc275ca65 100644
--- a/Documentation/perf_counter/builtin-record.c
+++ b/Documentation/perf_counter/builtin-record.c
@@ -162,7 +162,7 @@ struct comm_event {
         char                            comm[16];
 };
 
-static pid_t pid_synthesize_comm_event(pid_t pid)
+static void pid_synthesize_comm_event(pid_t pid, int full)
 {
         struct comm_event comm_ev;
         char filename[PATH_MAX];
@@ -170,6 +170,8 @@ static pid_t pid_synthesize_comm_event(pid_t pid)
         int fd, ret;
         size_t size;
         char *field, *sep;
+        DIR *tasks;
+        struct dirent dirent, *next;
 
         snprintf(filename, sizeof(filename), "/proc/%d/stat", pid);
 
@@ -194,29 +196,50 @@ static pid_t pid_synthesize_comm_event(pid_t pid)
                 goto out_failure;
         size = sep - field;
         memcpy(comm_ev.comm, field, size++);
-        field = strchr(sep + 4, ' ');
-        if (field == NULL)
-                goto out_failure;
-        comm_ev.pid = atoi(++field);
+
+        comm_ev.pid = pid;
         comm_ev.header.type = PERF_EVENT_COMM;
-        comm_ev.tid = pid;
         size = ALIGN(size, sizeof(uint64_t));
         comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
 
-        ret = write(output, &comm_ev, comm_ev.header.size);
-        if (ret < 0) {
-                perror("failed to write");
-                exit(-1);
+        if (!full) {
+                comm_ev.tid = pid;
+
+                ret = write(output, &comm_ev, comm_ev.header.size);
+                if (ret < 0) {
+                        perror("failed to write");
+                        exit(-1);
+                }
+                return;
+        }
+
+        snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
+
+        tasks = opendir(filename);
+        while (!readdir_r(tasks, &dirent, &next) && next) {
+                char *end;
+                pid = strtol(dirent.d_name, &end, 10);
+                if (*end)
+                        continue;
+
+                comm_ev.tid = pid;
+
+                ret = write(output, &comm_ev, comm_ev.header.size);
+                if (ret < 0) {
+                        perror("failed to write");
+                        exit(-1);
+                }
         }
-        return comm_ev.pid;
+        closedir(tasks);
+        return;
+
 out_failure:
         fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
                 filename);
         exit(EXIT_FAILURE);
-        return -1;
 }
 
-static void pid_synthesize_mmap_events(pid_t pid, pid_t pgid)
+static void pid_synthesize_mmap_events(pid_t pid)
 {
         char filename[PATH_MAX];
         FILE *fp;
@@ -261,7 +284,7 @@ static void pid_synthesize_mmap_events(pid_t pid, pid_t pgid)
                         mmap_ev.len -= mmap_ev.start;
                         mmap_ev.header.size = (sizeof(mmap_ev) -
                                                (sizeof(mmap_ev.filename) - size));
-                        mmap_ev.pid = pgid;
+                        mmap_ev.pid = pid;
                         mmap_ev.tid = pid;
 
                         if (write(output, &mmap_ev, mmap_ev.header.size) < 0) {
@@ -274,6 +297,28 @@ static void pid_synthesize_mmap_events(pid_t pid, pid_t pgid)
         fclose(fp);
 }
 
+static void synthesize_events(void)
+{
+        DIR *proc;
+        struct dirent dirent, *next;
+
+        proc = opendir("/proc");
+
+        while (!readdir_r(proc, &dirent, &next) && next) {
+                char *end;
+                pid_t pid;
+
+                pid = strtol(dirent.d_name, &end, 10);
+                if (*end) /* only interested in proper numerical dirents */
+                        continue;
+
+                pid_synthesize_comm_event(pid, 1);
+                pid_synthesize_mmap_events(pid);
+        }
+
+        closedir(proc);
+}
+
 static void open_counters(int cpu, pid_t pid)
 {
         struct perf_counter_hw_event hw_event;
@@ -281,8 +326,8 @@ static void open_counters(int cpu, pid_t pid)
         int track = 1;
 
         if (pid > 0) {
-                pid_t pgid = pid_synthesize_comm_event(pid);
-                pid_synthesize_mmap_events(pid, pgid);
+                pid_synthesize_comm_event(pid, 0);
+                pid_synthesize_mmap_events(pid);
         }
 
         group_fd = -1;
@@ -348,7 +393,7 @@ static int __cmd_record(int argc, const char **argv)
         assert(nr_cpus <= MAX_NR_CPUS);
         assert(nr_cpus >= 0);
 
-        output = open(output_name, O_CREAT|O_EXCL|O_RDWR, S_IRWXU);
+        output = open(output_name, O_CREAT|O_EXCL|O_TRUNC|O_RDWR, S_IRUSR|S_IWUSR);
         if (output < 0) {
                 perror("failed to create output file");
                 exit(-1);
@@ -385,9 +430,8 @@ static int __cmd_record(int argc, const char **argv)
                 }
         }
 
-        /*
-         * TODO: store the current /proc/$/maps information somewhere
-         */
+        if (system_wide)
+                synthesize_events();
 
         while (!done) {
                 int hits = events;