Switch event_pipe implementation to rely on new libbpf perf buffer API
(it's raw low-level variant).
Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
---
tools/bpf/bpftool/map_perf_ring.c | 207 ++++++++++--------------------
1 file changed, 68 insertions(+), 139 deletions(-)
diff --git a/tools/bpf/bpftool/map_perf_ring.c b/tools/bpf/bpftool/map_perf_ring.c
index 0507dfaf7a8f..4b048a53f8be 100644
--- a/tools/bpf/bpftool/map_perf_ring.c
+++ b/tools/bpf/bpftool/map_perf_ring.c
@@ -28,7 +28,7 @@
#define MMAP_PAGE_CNT 16
-static bool stop;
+static volatile bool stop;
struct event_ring_info {
int fd;
@@ -44,32 +44,44 @@ struct perf_event_sample {
unsigned char data[];
};
+struct perf_event_lost {
+ struct perf_event_header header;
+ __u64 id;
+ __u64 lost;
+};
+
static void int_exit(int signo)
{
fprintf(stderr, "Stopping...\n");
stop = true;
}
+struct event_pipe_ctx {
+ bool all_cpus;
+ int cpu;
+ int idx;
+};
+
static enum bpf_perf_event_ret
-print_bpf_output(struct perf_event_header *event, void *private_data)
+print_bpf_output(void *private_data, int cpu, struct perf_event_header *event)
{
- struct perf_event_sample *e = container_of(event, struct perf_event_sample,
+ struct perf_event_sample *e = container_of(event,
+ struct perf_event_sample,
header);
- struct event_ring_info *ring = private_data;
- struct {
- struct perf_event_header header;
- __u64 id;
- __u64 lost;
- } *lost = (typeof(lost))event;
+ struct perf_event_lost *lost = container_of(event,
+ struct perf_event_lost,
+ header);
+ struct event_pipe_ctx *ctx = private_data;
+ int idx = ctx->all_cpus ? cpu : ctx->idx;
if (json_output) {
jsonw_start_object(json_wtr);
jsonw_name(json_wtr, "type");
jsonw_uint(json_wtr, e->header.type);
jsonw_name(json_wtr, "cpu");
- jsonw_uint(json_wtr, ring->cpu);
+ jsonw_uint(json_wtr, cpu);
jsonw_name(json_wtr, "index");
- jsonw_uint(json_wtr, ring->key);
+ jsonw_uint(json_wtr, idx);
if (e->header.type == PERF_RECORD_SAMPLE) {
jsonw_name(json_wtr, "timestamp");
jsonw_uint(json_wtr, e->time);
@@ -89,7 +101,7 @@ print_bpf_output(struct perf_event_header *event, void *private_data)
if (e->header.type == PERF_RECORD_SAMPLE) {
printf("== @%lld.%09lld CPU: %d index: %d =====\n",
e->time / 1000000000ULL, e->time % 1000000000ULL,
- ring->cpu, ring->key);
+ cpu, idx);
fprint_hex(stdout, e->data, e->size, " ");
printf("\n");
} else if (e->header.type == PERF_RECORD_LOST) {
@@ -103,92 +115,32 @@ print_bpf_output(struct perf_event_header *event, void *private_data)
return LIBBPF_PERF_EVENT_CONT;
}
-static void
-perf_event_read(struct event_ring_info *ring, void **buf, size_t *buf_len)
-{
- enum bpf_perf_event_ret ret;
-
- ret = bpf_perf_event_read_simple(ring->mem,
- MMAP_PAGE_CNT * get_page_size(),
- get_page_size(), buf, buf_len,
- print_bpf_output, ring);
- if (ret != LIBBPF_PERF_EVENT_CONT) {
- fprintf(stderr, "perf read loop failed with %d\n", ret);
- stop = true;
- }
-}
-
-static int perf_mmap_size(void)
-{
- return get_page_size() * (MMAP_PAGE_CNT + 1);
-}
-
-static void *perf_event_mmap(int fd)
-{
- int mmap_size = perf_mmap_size();
- void *base;
-
- base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
- if (base == MAP_FAILED) {
- p_err("event mmap failed: %s\n", strerror(errno));
- return NULL;
- }
-
- return base;
-}
-
-static void perf_event_unmap(void *mem)
-{
- if (munmap(mem, perf_mmap_size()))
- fprintf(stderr, "Can't unmap ring memory!\n");
-}
-
-static int bpf_perf_event_open(int map_fd, int key, int cpu)
+int do_event_pipe(int argc, char **argv)
{
- struct perf_event_attr attr = {
+ struct perf_event_attr perf_attr = {
.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_TIME,
.type = PERF_TYPE_SOFTWARE,
.config = PERF_COUNT_SW_BPF_OUTPUT,
+ .sample_period = 1,
+ .wakeup_events = 1,
};
- int pmu_fd;
-
- pmu_fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
- if (pmu_fd < 0) {
- p_err("failed to open perf event %d for CPU %d", key, cpu);
- return -1;
- }
-
- if (bpf_map_update_elem(map_fd, &key, &pmu_fd, BPF_ANY)) {
- p_err("failed to update map for event %d for CPU %d", key, cpu);
- goto err_close;
- }
- if (ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0)) {
- p_err("failed to enable event %d for CPU %d", key, cpu);
- goto err_close;
- }
-
- return pmu_fd;
-
-err_close:
- close(pmu_fd);
- return -1;
-}
-
-int do_event_pipe(int argc, char **argv)
-{
- int i, nfds, map_fd, index = -1, cpu = -1;
struct bpf_map_info map_info = {};
- struct event_ring_info *rings;
- size_t tmp_buf_sz = 0;
- void *tmp_buf = NULL;
- struct pollfd *pfds;
+ struct perf_buffer_raw_opts opts;
+ struct event_pipe_ctx ctx = {
+ .all_cpus = true,
+ .cpu = -1,
+ .idx = -1,
+ };
+ struct perf_buffer *pb;
__u32 map_info_len;
- bool do_all = true;
+ int err, map_fd;
map_info_len = sizeof(map_info);
map_fd = map_parse_fd_and_info(&argc, &argv, &map_info, &map_info_len);
- if (map_fd < 0)
+ if (map_fd < 0) {
+ p_err("failed to get map info");
return -1;
+ }
if (map_info.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
p_err("map is not a perf event array");
@@ -205,7 +157,7 @@ int do_event_pipe(int argc, char **argv)
char *endptr;
NEXT_ARG();
- cpu = strtoul(*argv, &endptr, 0);
+ ctx.cpu = strtoul(*argv, &endptr, 0);
if (*endptr) {
p_err("can't parse %s as CPU ID", **argv);
goto err_close_map;
@@ -216,7 +168,7 @@ int do_event_pipe(int argc, char **argv)
char *endptr;
NEXT_ARG();
- index = strtoul(*argv, &endptr, 0);
+ ctx.idx = strtoul(*argv, &endptr, 0);
if (*endptr) {
p_err("can't parse %s as index", **argv);
goto err_close_map;
@@ -228,45 +180,32 @@ int do_event_pipe(int argc, char **argv)
goto err_close_map;
}
- do_all = false;
+ ctx.all_cpus = false;
}
- if (!do_all) {
- if (index == -1 || cpu == -1) {
+ if (!ctx.all_cpus) {
+ if (ctx.idx == -1 || ctx.cpu == -1) {
p_err("cpu and index must be specified together");
goto err_close_map;
}
-
- nfds = 1;
} else {
- nfds = min(get_possible_cpus(), map_info.max_entries);
- cpu = 0;
- index = 0;
+ ctx.cpu = 0;
+ ctx.idx = 0;
}
- rings = calloc(nfds, sizeof(rings[0]));
- if (!rings)
+ opts.attr = &perf_attr;
+ opts.event_cb = print_bpf_output;
+ opts.ctx = &ctx;
+ opts.cpu_cnt = ctx.all_cpus ? 0 : 1;
+ opts.cpus = &ctx.cpu;
+ opts.map_keys = &ctx.idx;
+
+ pb = perf_buffer__new_raw(map_fd, MMAP_PAGE_CNT, &opts);
+ err = libbpf_get_error(pb);
+ if (err) {
+ p_err("failed to create perf buffer: %s (%d)",
+ strerror(err), err);
goto err_close_map;
-
- pfds = calloc(nfds, sizeof(pfds[0]));
- if (!pfds)
- goto err_free_rings;
-
- for (i = 0; i < nfds; i++) {
- rings[i].cpu = cpu + i;
- rings[i].key = index + i;
-
- rings[i].fd = bpf_perf_event_open(map_fd, rings[i].key,
- rings[i].cpu);
- if (rings[i].fd < 0)
- goto err_close_fds_prev;
-
- rings[i].mem = perf_event_mmap(rings[i].fd);
- if (!rings[i].mem)
- goto err_close_fds_current;
-
- pfds[i].fd = rings[i].fd;
- pfds[i].events = POLLIN;
}
signal(SIGINT, int_exit);
@@ -277,35 +216,25 @@ int do_event_pipe(int argc, char **argv)
jsonw_start_array(json_wtr);
while (!stop) {
- poll(pfds, nfds, 200);
- for (i = 0; i < nfds; i++)
- perf_event_read(&rings[i], &tmp_buf, &tmp_buf_sz);
+ err = perf_buffer__poll(pb, 200);
+ if (err < 0 && err != -EINTR) {
+ p_err("perf buffer polling failed: %s (%d)",
+ strerror(err), err);
+ goto err_close_pb;
+ }
}
- free(tmp_buf);
if (json_output)
jsonw_end_array(json_wtr);
- for (i = 0; i < nfds; i++) {
- perf_event_unmap(rings[i].mem);
- close(rings[i].fd);
- }
- free(pfds);
- free(rings);
+ perf_buffer__free(pb);
close(map_fd);
return 0;
-err_close_fds_prev:
- while (i--) {
- perf_event_unmap(rings[i].mem);
-err_close_fds_current:
- close(rings[i].fd);
- }
- free(pfds);
-err_free_rings:
- free(rings);
+err_close_pb:
+ perf_buffer__free(pb);
err_close_map:
close(map_fd);
- return -1;
+ return err ? -1 : 0;
}
--
2.17.1
