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authorDavid Ahern <dsahern@gmail.com>2011-12-22 13:30:02 -0500
committerArnaldo Carvalho de Melo <acme@redhat.com>2011-12-23 13:33:57 -0500
commitf5faf726184a6a5ca1735f610cb97e509fce33e2 (patch)
treee69aaefb0316df7059f325cadcceace59f913581 /tools/perf
parentdefd8d38773cf9e01c69a903d04d5895b78ee74f (diff)
perf tools: Look up thread names for system wide profiling
This handles multithreaded processes with named threads when doing system wide profiling: the comm for each thread is looked up allowing them to be different from the thread group leader. v2: - fixed sizeof arg to perf_event__get_comm_tgid Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1324578603-12762-3-git-send-email-dsahern@gmail.com Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r--tools/perf/util/event.c75
1 files changed, 53 insertions, 22 deletions
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index a5787260181a..73ddaf06b8e7 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -43,37 +43,27 @@ static struct perf_sample synth_sample = {
43 .period = 1, 43 .period = 1,
44}; 44};
45 45
46static pid_t perf_event__synthesize_comm(struct perf_tool *tool, 46static pid_t perf_event__get_comm_tgid(pid_t pid, char *comm, size_t len)
47 union perf_event *event, pid_t pid,
48 int full, perf_event__handler_t process,
49 struct machine *machine)
50{ 47{
51 char filename[PATH_MAX]; 48 char filename[PATH_MAX];
52 char bf[BUFSIZ]; 49 char bf[BUFSIZ];
53 FILE *fp; 50 FILE *fp;
54 size_t size = 0; 51 size_t size = 0;
55 DIR *tasks; 52 pid_t tgid = -1;
56 struct dirent dirent, *next;
57 pid_t tgid = 0;
58 53
59 snprintf(filename, sizeof(filename), "/proc/%d/status", pid); 54 snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
60 55
61 fp = fopen(filename, "r"); 56 fp = fopen(filename, "r");
62 if (fp == NULL) { 57 if (fp == NULL) {
63out_race:
64 /*
65 * We raced with a task exiting - just return:
66 */
67 pr_debug("couldn't open %s\n", filename); 58 pr_debug("couldn't open %s\n", filename);
68 return 0; 59 return 0;
69 } 60 }
70 61
71 memset(&event->comm, 0, sizeof(event->comm)); 62 while (!comm[0] || (tgid < 0)) {
72
73 while (!event->comm.comm[0] || !event->comm.pid) {
74 if (fgets(bf, sizeof(bf), fp) == NULL) { 63 if (fgets(bf, sizeof(bf), fp) == NULL) {
75 pr_warning("couldn't get COMM and pgid, malformed %s\n", filename); 64 pr_warning("couldn't get COMM and pgid, malformed %s\n",
76 goto out; 65 filename);
66 break;
77 } 67 }
78 68
79 if (memcmp(bf, "Name:", 5) == 0) { 69 if (memcmp(bf, "Name:", 5) == 0) {
@@ -81,16 +71,46 @@ out_race:
81 while (*name && isspace(*name)) 71 while (*name && isspace(*name))
82 ++name; 72 ++name;
83 size = strlen(name) - 1; 73 size = strlen(name) - 1;
84 memcpy(event->comm.comm, name, size++); 74 if (size >= len)
75 size = len - 1;
76 memcpy(comm, name, size);
77
85 } else if (memcmp(bf, "Tgid:", 5) == 0) { 78 } else if (memcmp(bf, "Tgid:", 5) == 0) {
86 char *tgids = bf + 5; 79 char *tgids = bf + 5;
87 while (*tgids && isspace(*tgids)) 80 while (*tgids && isspace(*tgids))
88 ++tgids; 81 ++tgids;
89 tgid = event->comm.pid = atoi(tgids); 82 tgid = atoi(tgids);
90 } 83 }
91 } 84 }
92 85
86 fclose(fp);
87
88 return tgid;
89}
90
91static pid_t perf_event__synthesize_comm(struct perf_tool *tool,
92 union perf_event *event, pid_t pid,
93 int full,
94 perf_event__handler_t process,
95 struct machine *machine)
96{
97 char filename[PATH_MAX];
98 size_t size;
99 DIR *tasks;
100 struct dirent dirent, *next;
101 pid_t tgid;
102
103 memset(&event->comm, 0, sizeof(event->comm));
104
105 tgid = perf_event__get_comm_tgid(pid, event->comm.comm,
106 sizeof(event->comm.comm));
107 if (tgid < 0)
108 goto out;
109
110 event->comm.pid = tgid;
93 event->comm.header.type = PERF_RECORD_COMM; 111 event->comm.header.type = PERF_RECORD_COMM;
112
113 size = strlen(event->comm.comm) + 1;
94 size = ALIGN(size, sizeof(u64)); 114 size = ALIGN(size, sizeof(u64));
95 memset(event->comm.comm + size, 0, machine->id_hdr_size); 115 memset(event->comm.comm + size, 0, machine->id_hdr_size);
96 event->comm.header.size = (sizeof(event->comm) - 116 event->comm.header.size = (sizeof(event->comm) -
@@ -106,8 +126,10 @@ out_race:
106 snprintf(filename, sizeof(filename), "/proc/%d/task", pid); 126 snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
107 127
108 tasks = opendir(filename); 128 tasks = opendir(filename);
109 if (tasks == NULL) 129 if (tasks == NULL) {
110 goto out_race; 130 pr_debug("couldn't open %s\n", filename);
131 return 0;
132 }
111 133
112 while (!readdir_r(tasks, &dirent, &next) && next) { 134 while (!readdir_r(tasks, &dirent, &next) && next) {
113 char *end; 135 char *end;
@@ -115,6 +137,17 @@ out_race:
115 if (*end) 137 if (*end)
116 continue; 138 continue;
117 139
140 /* already have tgid; jut want to update the comm */
141 (void) perf_event__get_comm_tgid(pid, event->comm.comm,
142 sizeof(event->comm.comm));
143
144 size = strlen(event->comm.comm) + 1;
145 size = ALIGN(size, sizeof(u64));
146 memset(event->comm.comm + size, 0, machine->id_hdr_size);
147 event->comm.header.size = (sizeof(event->comm) -
148 (sizeof(event->comm.comm) - size) +
149 machine->id_hdr_size);
150
118 event->comm.tid = pid; 151 event->comm.tid = pid;
119 152
120 process(tool, event, &synth_sample, machine); 153 process(tool, event, &synth_sample, machine);
@@ -122,8 +155,6 @@ out_race:
122 155
123 closedir(tasks); 156 closedir(tasks);
124out: 157out:
125 fclose(fp);
126
127 return tgid; 158 return tgid;
128} 159}
129 160