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5ed3ccbd5a
There are two improvements in this patch:
1. Fix the build warnings;
2. Add function read_trace_pipe() to print the result on
the screen;
Before this patch, we can get the result through /sys/kernel/de
bug/tracing/trace_pipe and get nothing on the screen.
By applying this patch, the result can be printed on the screen.
$ ./tracex6
...
tracex6-705 [003] d..1 131.428593: : CPU-3 19981414
sshd-683 [000] d..1 131.428727: : CPU-0 221682321
sshd-683 [000] d..1 131.428821: : CPU-0 221808766
sshd-683 [000] d..1 131.428950: : CPU-0 221982984
sshd-683 [000] d..1 131.429045: : CPU-0 222111851
tracex6-705 [003] d..1 131.429168: : CPU-3 20757551
sshd-683 [000] d..1 131.429170: : CPU-0 222281240
sshd-683 [000] d..1 131.429261: : CPU-0 222403340
sshd-683 [000] d..1 131.429378: : CPU-0 222561024
...
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
73 lines
1.4 KiB
C
73 lines
1.4 KiB
C
#include <stdio.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <stdbool.h>
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#include <string.h>
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#include <fcntl.h>
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#include <poll.h>
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#include <sys/ioctl.h>
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#include <linux/perf_event.h>
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#include <linux/bpf.h>
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#include "libbpf.h"
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#include "bpf_load.h"
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#define SAMPLE_PERIOD 0x7fffffffffffffffULL
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static void test_bpf_perf_event(void)
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{
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int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
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int *pmu_fd = malloc(nr_cpus * sizeof(int));
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int status, i;
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struct perf_event_attr attr_insn_pmu = {
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.freq = 0,
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.sample_period = SAMPLE_PERIOD,
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.inherit = 0,
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.type = PERF_TYPE_HARDWARE,
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.read_format = 0,
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.sample_type = 0,
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.config = 0,/* PMU: cycles */
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};
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for (i = 0; i < nr_cpus; i++) {
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pmu_fd[i] = perf_event_open(&attr_insn_pmu, -1/*pid*/, i/*cpu*/, -1/*group_fd*/, 0);
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if (pmu_fd[i] < 0) {
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printf("event syscall failed\n");
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goto exit;
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}
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bpf_update_elem(map_fd[0], &i, &pmu_fd[i], BPF_ANY);
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ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0);
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}
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status = system("ls > /dev/null");
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if (status)
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goto exit;
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status = system("sleep 2");
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if (status)
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goto exit;
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exit:
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for (i = 0; i < nr_cpus; i++)
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close(pmu_fd[i]);
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close(map_fd[0]);
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free(pmu_fd);
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}
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int main(int argc, char **argv)
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{
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char filename[256];
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snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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if (load_bpf_file(filename)) {
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printf("%s", bpf_log_buf);
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return 1;
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}
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test_bpf_perf_event();
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read_trace_pipe();
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return 0;
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}
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