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samples/bpf: convert xdp_sample_pkts_user to perf_buffer API 

Convert xdp_sample_pkts_user to libbpf's perf_buffer API.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Andrii Nakryiko 2019-07-23 14:34:43 -07:00 committed by Alexei Starovoitov
parent 898ca681cd
commit f58a4d51d8
1 changed files with 17 additions and 44 deletions
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61
samples/bpf/xdp_sample_pkts_user.c
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@ -17,14 +17,13 @@
#include <linux/if_link.h>
#include "perf-sys.h"
#include "trace_helpers.h"
#define MAX_CPUS 128
static int pmu_fds[MAX_CPUS], if_idx;
static struct perf_event_mmap_page *headers[MAX_CPUS];
static int if_idx;
static char *if_name;
static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
static __u32 prog_id;
static struct perf_buffer *pb = NULL;
static int do_attach(int idx, int fd, const char *name)
{
@ -73,7 +72,7 @@ static int do_detach(int idx, const char *name)
#define SAMPLE_SIZE 64
static int print_bpf_output(void *data, int size)
static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
{
struct {
__u16 cookie;
@ -83,45 +82,20 @@ static int print_bpf_output(void *data, int size)
int i;
if (e->cookie != 0xdead) {
printf("BUG cookie %x sized %d\n",
e->cookie, size);
return LIBBPF_PERF_EVENT_ERROR;
printf("BUG cookie %x sized %d\n", e->cookie, size);
return;
}
printf("Pkt len: %-5d bytes. Ethernet hdr: ", e->pkt_len);
for (i = 0; i < 14 && i < e->pkt_len; i++)
printf("%02x ", e->pkt_data[i]);
printf("\n");
return LIBBPF_PERF_EVENT_CONT;
}
static void test_bpf_perf_event(int map_fd, int num)
{
struct perf_event_attr attr = {
.sample_type = PERF_SAMPLE_RAW,
.type = PERF_TYPE_SOFTWARE,
.config = PERF_COUNT_SW_BPF_OUTPUT,
.wakeup_events = 1, /* get an fd notification for every event */
};
int i;
for (i = 0; i < num; i++) {
int key = i;
pmu_fds[i] = sys_perf_event_open(&attr, -1/*pid*/, i/*cpu*/,
-1/*group_fd*/, 0);
assert(pmu_fds[i] >= 0);
assert(bpf_map_update_elem(map_fd, &key,
&pmu_fds[i], BPF_ANY) == 0);
ioctl(pmu_fds[i], PERF_EVENT_IOC_ENABLE, 0);
}
}
static void sig_handler(int signo)
{
do_detach(if_idx, if_name);
perf_buffer__free(pb);
exit(0);
}
@ -140,13 +114,13 @@ int main(int argc, char **argv)
struct bpf_prog_load_attr prog_load_attr = {
.prog_type = BPF_PROG_TYPE_XDP,
};
struct perf_buffer_opts pb_opts = {};
const char *optstr = "F";
int prog_fd, map_fd, opt;
struct bpf_object *obj;
struct bpf_map *map;
char filename[256];
int ret, err, i;
int numcpus;
int ret, err;
while ((opt = getopt(argc, argv, optstr)) != -1) {
switch (opt) {
@ -169,10 +143,6 @@ int main(int argc, char **argv)
return 1;
}
numcpus = get_nprocs();
if (numcpus > MAX_CPUS)
numcpus = MAX_CPUS;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
prog_load_attr.file = filename;
@ -211,14 +181,17 @@ int main(int argc, char **argv)
return 1;
}
test_bpf_perf_event(map_fd, numcpus);
pb_opts.sample_cb = print_bpf_output;
pb = perf_buffer__new(map_fd, 8, &pb_opts);
err = libbpf_get_error(pb);
if (err) {
perror("perf_buffer setup failed");
return 1;
}
for (i = 0; i < numcpus; i++)
if (perf_event_mmap_header(pmu_fds[i], &headers[i]) < 0)
return 1;
while ((ret = perf_buffer__poll(pb, 1000)) >= 0) {
}
ret = perf_event_poller_multi(pmu_fds, headers, numcpus,
print_bpf_output);
kill(0, SIGINT);
return ret;
}