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authorJakub Kicinski <jakub.kicinski@netronome.com>2018-05-10 10:24:40 -0700
committerDaniel Borkmann <daniel@iogearbox.net>2018-05-11 01:40:52 +0200
commitd0cabbb021bee5c4b831a0235af9534ad07f8d3d (patch)
tree7843337206d80588110d9112d49836624b09be64 /tools/testing/selftests/bpf/trace_helpers.c
parent5f9380572b4bb24f60cd492b17331db6ee34a516 (diff)
tools: bpf: move the event reading loop to libbpf
There are two copies of event reading loop - in bpftool and trace_helpers "library". Consolidate them and move the code to libbpf. Return codes from trace_helpers are kept, but renamed to include LIBBPF prefix. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools/testing/selftests/bpf/trace_helpers.c')
-rw-r--r--tools/testing/selftests/bpf/trace_helpers.c87
1 files changed, 30 insertions, 57 deletions
diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
index ad025bd75f1c..8fb4fe8686e4 100644
--- a/tools/testing/selftests/bpf/trace_helpers.c
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -74,7 +74,7 @@ struct ksym *ksym_search(long key)
static int page_size;
static int page_cnt = 8;
-static volatile struct perf_event_mmap_page *header;
+static struct perf_event_mmap_page *header;
int perf_event_mmap(int fd)
{
@@ -107,74 +107,47 @@ struct perf_event_sample {
char data[];
};
-static int perf_event_read(perf_event_print_fn fn)
+static enum bpf_perf_event_ret bpf_perf_event_print(void *event, void *priv)
{
- __u64 data_tail = header->data_tail;
- __u64 data_head = header->data_head;
- __u64 buffer_size = page_cnt * page_size;
- void *base, *begin, *end;
- char buf[256];
+ struct perf_event_sample *e = event;
+ perf_event_print_fn fn = priv;
int ret;
- asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */
- if (data_head == data_tail)
- return PERF_EVENT_CONT;
-
- base = ((char *)header) + page_size;
-
- begin = base + data_tail % buffer_size;
- end = base + data_head % buffer_size;
-
- while (begin != end) {
- struct perf_event_sample *e;
-
- e = begin;
- if (begin + e->header.size > base + buffer_size) {
- long len = base + buffer_size - begin;
-
- assert(len < e->header.size);
- memcpy(buf, begin, len);
- memcpy(buf + len, base, e->header.size - len);
- e = (void *) buf;
- begin = base + e->header.size - len;
- } else if (begin + e->header.size == base + buffer_size) {
- begin = base;
- } else {
- begin += e->header.size;
- }
-
- if (e->header.type == PERF_RECORD_SAMPLE) {
- ret = fn(e->data, e->size);
- if (ret != PERF_EVENT_CONT)
- return ret;
- } else if (e->header.type == PERF_RECORD_LOST) {
- struct {
- struct perf_event_header header;
- __u64 id;
- __u64 lost;
- } *lost = (void *) e;
- printf("lost %lld events\n", lost->lost);
- } else {
- printf("unknown event type=%d size=%d\n",
- e->header.type, e->header.size);
- }
+ if (e->header.type == PERF_RECORD_SAMPLE) {
+ ret = fn(e->data, e->size);
+ if (ret != LIBBPF_PERF_EVENT_CONT)
+ return ret;
+ } else if (e->header.type == PERF_RECORD_LOST) {
+ struct {
+ struct perf_event_header header;
+ __u64 id;
+ __u64 lost;
+ } *lost = (void *) e;
+ printf("lost %lld events\n", lost->lost);
+ } else {
+ printf("unknown event type=%d size=%d\n",
+ e->header.type, e->header.size);
}
- __sync_synchronize(); /* smp_mb() */
- header->data_tail = data_head;
- return PERF_EVENT_CONT;
+ return LIBBPF_PERF_EVENT_CONT;
}
int perf_event_poller(int fd, perf_event_print_fn output_fn)
{
- int ret;
+ enum bpf_perf_event_ret ret;
+ void *buf = NULL;
+ size_t len = 0;
for (;;) {
perf_event_poll(fd);
- ret = perf_event_read(output_fn);
- if (ret != PERF_EVENT_CONT)
- return ret;
+ ret = bpf_perf_event_read_simple(header, page_cnt * page_size,
+ page_size, &buf, &len,
+ bpf_perf_event_print,
+ output_fn);
+ if (ret != LIBBPF_PERF_EVENT_CONT)
+ break;
}
+ free(buf);
- return PERF_EVENT_DONE;
+ return ret;
}