linux_dsm_epyc7002/samples/bpf/tracex6_kern.c
Kaixu Xia 47efb30274 samples/bpf: example of get selected PMU counter value
This is a simple example and shows how to use the new ability
to get the selected Hardware PMU counter value.

Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-09 22:50:06 -07:00

27 lines
585 B
C

#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include "bpf_helpers.h"
struct bpf_map_def SEC("maps") my_map = {
.type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(u32),
.max_entries = 32,
};
SEC("kprobe/sys_write")
int bpf_prog1(struct pt_regs *ctx)
{
u64 count;
u32 key = bpf_get_smp_processor_id();
char fmt[] = "CPU-%d %llu\n";
count = bpf_perf_event_read(&my_map, key);
bpf_trace_printk(fmt, sizeof(fmt), key, count);
return 0;
}
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;