1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
#include <stdlib.h>
#include <ctype.h>
#include <tracefs.h>
static void read_subbuf(struct tep_handle *tep, struct kbuffer *kbuf)
{
static struct trace_seq seq;
struct tep_record record;
int missed_events;
if (seq.buffer)
trace_seq_reset(&seq);
else
trace_seq_init(&seq);
while ((record.data = kbuffer_read_event(kbuf, &record.ts))) {
record.size = kbuffer_event_size(kbuf);
missed_events = kbuffer_missed_events(kbuf);
if (missed_events) {
printf("[MISSED EVENTS");
if (missed_events > 0)
printf(": %d]\n", missed_events);
else
printf("]\n");
}
kbuffer_next_event(kbuf, NULL);
tep_print_event(tep, &seq, &record,
"%s-%d %6.1000d\t%s: %s\n",
TEP_PRINT_COMM,
TEP_PRINT_PID,
TEP_PRINT_TIME,
TEP_PRINT_NAME,
TEP_PRINT_INFO);
trace_seq_do_printf(&seq);
trace_seq_reset(&seq);
}
}
int main (int argc, char **argv)
{
struct tracefs_cpu *tcpu;
struct tep_handle *tep;
struct kbuffer *kbuf;
bool mapped;
int cpu;
if (argc < 2 || !isdigit(argv[1][0])) {
printf("usage: %s cpu\n\n", argv[0]);
exit(-1);
}
cpu = atoi(argv[1]);
tep = tracefs_local_events(NULL);
if (!tep) {
perror("Reading trace event formats");
exit(-1);
}
tcpu = tracefs_cpu_open_mapped(NULL, cpu, 0);
if (!tcpu) {
perror("Open CPU 0 file");
exit(-1);
}
/*
* If this kernel supports mapping, use normal read,
* otherwise use the piped buffer read, although if
* the mapping succeeded, tracefs_cpu_buffered_read_buf()
* acts the same as tracefs_cpu_read_buf(). But this is just
* an example on how to use tracefs_cpu_is_mapped().
*/
mapped = tracefs_cpu_is_mapped(tcpu);
if (!mapped)
printf("Was not able to map, falling back to buffered read\n");
while ((kbuf = mapped ? tracefs_cpu_read_buf(tcpu, true) :
tracefs_cpu_buffered_read_buf(tcpu, true))) {
read_subbuf(tep, kbuf);
}
kbuf = tracefs_cpu_flush_buf(tcpu);
if (kbuf)
read_subbuf(tep, kbuf);
tracefs_cpu_close(tcpu);
tep_free(tep);
return 0;
}
|
