samples/bpf: add tests for more perf event types
$ trace_event
tests attaching BPF program to HW_CPU_CYCLES, SW_CPU_CLOCK, HW_CACHE_L1D and other events.
It runs 'dd' in the background while bpf program collects user and kernel
stack trace on counter overflow.
User space expects to see sys_read and sys_write in the kernel stack.
$ tracex6
tests reading of various perf counters from BPF program.
Both tests were refactored to increase coverage and be more accurate.
Signed-off-by: Teng Qin <qinteng@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/samples/bpf/tracex6_kern.c b/samples/bpf/tracex6_kern.c
index be479c4..e7d1803 100644
--- a/samples/bpf/tracex6_kern.c
+++ b/samples/bpf/tracex6_kern.c
@@ -3,22 +3,36 @@
#include <uapi/linux/bpf.h>
#include "bpf_helpers.h"
-struct bpf_map_def SEC("maps") my_map = {
+struct bpf_map_def SEC("maps") counters = {
.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(u32),
- .max_entries = 32,
+ .max_entries = 64,
+};
+struct bpf_map_def SEC("maps") values = {
+ .type = BPF_MAP_TYPE_HASH,
+ .key_size = sizeof(int),
+ .value_size = sizeof(u64),
+ .max_entries = 64,
};
-SEC("kprobe/sys_write")
+SEC("kprobe/htab_map_get_next_key")
int bpf_prog1(struct pt_regs *ctx)
{
- u64 count;
u32 key = bpf_get_smp_processor_id();
- char fmt[] = "CPU-%d %llu\n";
+ u64 count, *val;
+ s64 error;
- count = bpf_perf_event_read(&my_map, key);
- bpf_trace_printk(fmt, sizeof(fmt), key, count);
+ count = bpf_perf_event_read(&counters, key);
+ error = (s64)count;
+ if (error <= -2 && error >= -22)
+ return 0;
+
+ val = bpf_map_lookup_elem(&values, &key);
+ if (val)
+ *val = count;
+ else
+ bpf_map_update_elem(&values, &key, &count, BPF_NOEXIST);
return 0;
}
