FM / tracing

/usr/share/doc/bpfcc-tools/examples/tracing/

/usr/share/doc/bpfcc-tools/examples/tracing

Name	Size	Mode	Actions
biolatpcts.py	3312	0755	edit dl rm
biolatpcts_example.txt	650	0644	edit dl rm
bitehist.py	1397	0755	edit dl rm
bitehist_example.txt	1208	0644	edit dl rm
CMakeLists.txt	276	0644	edit dl rm
dddos.py	3818	0755	edit dl rm
dddos_example.txt	2112	0644	edit dl rm
disksnoop.py	1947	0755	edit dl rm
disksnoop_example.txt	1587	0644	edit dl rm
hello_fields.py	679	0755	edit dl rm
hello_perf_output.py	1270	0755	edit dl rm
hello_perf_output_using_ns.py	1843	0755	edit dl rm
kvm_hypercall.py	1520	0755	edit dl rm
kvm_hypercall.txt	1782	0644	edit dl rm
mallocstacks.py	1942	0755	edit dl rm
mysqld_query.py	1701	0755	edit dl rm
mysqld_query_example.txt	499	0644	edit dl rm
nflatency.py	6214	0755	edit dl rm
nodejs_http_server.py	1376	0755	edit dl rm
nodejs_http_server_example.txt	276	0644	edit dl rm
stacksnoop.py	3252	0755	edit dl rm
stacksnoop_example.txt	2871	0644	edit dl rm
stack_buildid_example.py	3106	0755	edit dl rm
strlen_count.py	1331	0755	edit dl rm
strlen_hist.py	1856	0755	edit dl rm
strlen_hist_ifunc.py	3800	0755	edit dl rm
strlen_snoop.py	1384	0755	edit dl rm
sync_timing.py	1390	0755	edit dl rm
task_switch.c	499	0644	edit dl rm
task_switch.py	486	0755	edit dl rm
tcpv4connect.py	2413	0755	edit dl rm
tcpv4connect_example.txt	1063	0644	edit dl rm
trace_fields.py	589	0755	edit dl rm
trace_perf_output.py	1600	0755	edit dl rm
undump.py	3602	0755	edit dl rm
undump_example.txt	886	0644	edit dl rm
urandomread-explicit.py	1511	0755	edit dl rm
urandomread.py	1032	0755	edit dl rm
urandomread_example.txt	675	0644	edit dl rm
vfsreadlat.c	896	0644	edit dl rm
vfsreadlat.py	1336	0755	edit dl rm
vfsreadlat_example.txt	3619	0644	edit dl rm

Edit: /usr/share/doc/bpfcc-tools/examples/tracing/hello_perf_output.py (1270B)

#!/usr/bin/python
#
# This is a Hello World example that uses BPF_PERF_OUTPUT.

from bcc import BPF
from bcc.utils import printb

# define BPF program
prog = """
#include <linux/sched.h>

// define output data structure in C
struct data_t {
    u32 pid;
    u64 ts;
    char comm[TASK_COMM_LEN];
};
BPF_PERF_OUTPUT(events);

int hello(struct pt_regs *ctx) {
    struct data_t data = {};

data.pid = bpf_get_current_pid_tgid();
    data.ts = bpf_ktime_get_ns();
    bpf_get_current_comm(&data.comm, sizeof(data.comm));

events.perf_submit(ctx, &data, sizeof(data));

return 0;
}
"""

# load BPF program
b = BPF(text=prog)
b.attach_kprobe(event=b.get_syscall_fnname("clone"), fn_name="hello")

# header
print("%-18s %-16s %-6s %s" % ("TIME(s)", "COMM", "PID", "MESSAGE"))

# process event
start = 0
def print_event(cpu, data, size):
    global start
    event = b["events"].event(data)
    if start == 0:
            start = event.ts
    time_s = (float(event.ts - start)) / 1000000000
    printb(b"%-18.9f %-16s %-6d %s" % (time_s, event.comm, event.pid,
        b"Hello, perf_output!"))

# loop with callback to print_event
b["events"].open_perf_buffer(print_event)
while 1:
    try:
        b.perf_buffer_poll()
    except KeyboardInterrupt:
        exit()

cmd: