From 47efb30274cbec1bd3c0c980a7ece328df2c16a8 Mon Sep 17 00:00:00 2001 From: Kaixu Xia Date: Thu, 6 Aug 2015 07:02:36 +0000 Subject: 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 Signed-off-by: David S. Miller --- samples/bpf/tracex6_kern.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 samples/bpf/tracex6_kern.c (limited to 'samples/bpf/tracex6_kern.c') diff --git a/samples/bpf/tracex6_kern.c b/samples/bpf/tracex6_kern.c new file mode 100644 index 000000000000..23d1cffaf249 --- /dev/null +++ b/samples/bpf/tracex6_kern.c @@ -0,0 +1,26 @@ +#include +#include +#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; -- cgit v1.2.3