mirror of
https://github.com/varun-r-mallya/Python-BPF.git
synced 2025-12-31 21:06:25 +00:00
47 lines
1.1 KiB
Python
47 lines
1.1 KiB
Python
from __future__ import print_function
|
|
from bcc import BPF
|
|
from bcc.utils import printb
|
|
|
|
# load BPF program
|
|
b = BPF(text="""
|
|
#include <uapi/linux/ptrace.h>
|
|
|
|
BPF_HASH(last);
|
|
|
|
int do_trace(struct pt_regs *ctx) {
|
|
u64 ts, *tsp, delta, key = 0;
|
|
|
|
// attempt to read stored timestamp
|
|
tsp = last.lookup(&key);
|
|
if (tsp != NULL) {
|
|
delta = bpf_ktime_get_ns() - *tsp;
|
|
if (delta < 1000000000) {
|
|
// output if time is less than 1 second
|
|
bpf_trace_printk("%d\\n", delta / 1000000);
|
|
}
|
|
last.delete(&key);
|
|
}
|
|
|
|
// update stored timestamp
|
|
ts = bpf_ktime_get_ns();
|
|
last.update(&key, &ts);
|
|
return 0;
|
|
}
|
|
""")
|
|
|
|
b.attach_kprobe(event=b.get_syscall_fnname("sync"), fn_name="do_trace")
|
|
print("Tracing for quick sync's... Ctrl-C to end")
|
|
|
|
# TODO
|
|
# format output
|
|
start = 0
|
|
while 1:
|
|
try:
|
|
(task, pid, cpu, flags, ts, ms) = b.trace_fields()
|
|
if start == 0:
|
|
start = ts
|
|
ts = ts - start
|
|
printb(b"At time %.2f s: multiple syncs detected, last %s ms ago" % (ts, ms))
|
|
except KeyboardInterrupt:
|
|
exit()
|