Files
python-bpf/BCC-Examples/disksnoop.py
2025-11-30 05:53:32 +05:30

59 lines
1.3 KiB
Python

from vmlinux import struct_request, struct_pt_regs
from pythonbpf import bpf, section, bpfglobal, compile, map
from pythonbpf.helper import ktime
from pythonbpf.maps import HashMap
from ctypes import c_int64, c_uint64, c_int32
# Constants
REQ_WRITE = 1 # from include/linux/blk_types.h
@bpf
@map
def start() -> HashMap:
return HashMap(key=c_uint64, value=c_uint64, max_entries=10240)
@bpf
@section("kprobe/blk_mq_end_request")
def trace_completion(ctx: struct_pt_regs) -> c_int64:
# Get request pointer from first argument
req_ptr = ctx.di
req = struct_request(ctx.di)
# Print: data_len, cmd_flags, latency_us
data_len = req.__data_len
cmd_flags = req.cmd_flags
# Lookup start timestamp
req_tsp = start.lookup(req_ptr)
if req_tsp:
# Calculate delta in nanoseconds
delta = ktime() - req_tsp
# Convert to microseconds for printing
delta_us = delta // 1000
print(f"{data_len} {cmd_flags:x} {delta_us}\n")
# Delete the entry
start.delete(req_ptr)
return c_int64(0)
@bpf
@section("kprobe/blk_mq_start_request")
def trace_start(ctx1: struct_pt_regs) -> c_int32:
req = ctx1.di
ts = ktime()
start.update(req, ts)
return c_int32(0)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile()