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authorAndrii Nakryiko <andriin@fb.com>2019-07-24 00:34:44 +0300
committerAlexei Starovoitov <ast@kernel.org>2019-07-24 02:05:42 +0300
commitc17bec549c9dc969b4e725c56aa9ebb125378397 (patch)
tree23335974151011cdad8183fffed21db675ea75d1 /samples/bpf/trace_output_user.c
parentf58a4d51d8da7b248d8796e9981feb3d5a43d3d2 (diff)
downloadlinux-c17bec549c9dc969b4e725c56aa9ebb125378397.tar.xz
samples/bpf: switch trace_output sample to perf_buffer API
Convert trace_output sample to libbpf's perf_buffer API. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'samples/bpf/trace_output_user.c')
-rw-r--r--samples/bpf/trace_output_user.c43
1 files changed, 14 insertions, 29 deletions
diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c
index 2dd1d39b152a..8ee47699a870 100644
--- a/samples/bpf/trace_output_user.c
+++ b/samples/bpf/trace_output_user.c
@@ -18,9 +18,6 @@
#include <libbpf.h>
#include "bpf_load.h"
#include "perf-sys.h"
-#include "trace_helpers.h"
-
-static int pmu_fd;
static __u64 time_get_ns(void)
{
@@ -31,12 +28,12 @@ static __u64 time_get_ns(void)
}
static __u64 start_time;
+static __u64 cnt;
#define MAX_CNT 100000ll
-static int print_bpf_output(void *data, int size)
+static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
{
- static __u64 cnt;
struct {
__u64 pid;
__u64 cookie;
@@ -45,7 +42,7 @@ static int print_bpf_output(void *data, int size)
if (e->cookie != 0x12345678) {
printf("BUG pid %llx cookie %llx sized %d\n",
e->pid, e->cookie, size);
- return LIBBPF_PERF_EVENT_ERROR;
+ return;
}
cnt++;
@@ -53,30 +50,14 @@ static int print_bpf_output(void *data, int size)
if (cnt == MAX_CNT) {
printf("recv %lld events per sec\n",
MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
- return LIBBPF_PERF_EVENT_DONE;
+ return;
}
-
- return LIBBPF_PERF_EVENT_CONT;
-}
-
-static void test_bpf_perf_event(void)
-{
- struct perf_event_attr attr = {
- .sample_type = PERF_SAMPLE_RAW,
- .type = PERF_TYPE_SOFTWARE,
- .config = PERF_COUNT_SW_BPF_OUTPUT,
- };
- int key = 0;
-
- pmu_fd = sys_perf_event_open(&attr, -1/*pid*/, 0/*cpu*/, -1/*group_fd*/, 0);
-
- assert(pmu_fd >= 0);
- assert(bpf_map_update_elem(map_fd[0], &key, &pmu_fd, BPF_ANY) == 0);
- ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
}
int main(int argc, char **argv)
{
+ struct perf_buffer_opts pb_opts = {};
+ struct perf_buffer *pb;
char filename[256];
FILE *f;
int ret;
@@ -88,16 +69,20 @@ int main(int argc, char **argv)
return 1;
}
- test_bpf_perf_event();
-
- if (perf_event_mmap(pmu_fd) < 0)
+ pb_opts.sample_cb = print_bpf_output;
+ pb = perf_buffer__new(map_fd[0], 8, &pb_opts);
+ ret = libbpf_get_error(pb);
+ if (ret) {
+ printf("failed to setup perf_buffer: %d\n", ret);
return 1;
+ }
f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
(void) f;
start_time = time_get_ns();
- ret = perf_event_poller(pmu_fd, print_bpf_output);
+ while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) {
+ }
kill(0, SIGINT);
return ret;
}