xref: /aosp_15_r20/external/bcc/tools/mysqld_qslower.py (revision 387f9dfdfa2baef462e92476d413c7bc2470293e) 
1#!/usr/bin/env python
2#
3# mysqld_qslower    MySQL server queries slower than a threshold.
4#                   For Linux, uses BCC, BPF. Embedded C.
5#
6# USAGE: mysqld_qslower PID [min_ms]
7#
8# By default, a threshold of 1.0 ms is used. Set this to 0 ms to trace all
9# queries (verbose).
10#
11# This uses USDT probes, and needs a MySQL server with -DENABLE_DTRACE=1.
12#
13# Copyright 2016 Netflix, Inc.
14# Licensed under the Apache License, Version 2.0 (the "License")
15#
16# 30-Jul-2016   Brendan Gregg   Created this.
17
18from __future__ import print_function
19from bcc import BPF, USDT
20import sys
21
22# arguments
23def usage():
24    print("USAGE: mysqld_qslower PID [min_ms]")
25    exit()
26if len(sys.argv) < 2:
27    usage()
28if sys.argv[1][0:1] == "-":
29    usage()
30pid = int(sys.argv[1])
31min_ns = 1 * 1000000
32min_ms_text = 1
33if len(sys.argv) == 3:
34    min_ns = float(sys.argv[2]) * 1000000
35    min_ms_text = sys.argv[2]
36debug = 0
37QUERY_MAX = 128
38
39# load BPF program
40bpf_text = """
41#include <uapi/linux/ptrace.h>
42
43#define QUERY_MAX	""" + str(QUERY_MAX) + """
44
45struct start_t {
46    u64 ts;
47    char *query;
48};
49
50struct data_t {
51    u32 pid;
52    u64 ts;
53    u64 delta;
54    char query[QUERY_MAX];
55};
56
57BPF_HASH(start_tmp, u32, struct start_t);
58BPF_PERF_OUTPUT(events);
59
60int do_start(struct pt_regs *ctx) {
61    u32 tid = bpf_get_current_pid_tgid();
62    struct start_t start = {};
63    start.ts = bpf_ktime_get_ns();
64    bpf_usdt_readarg(1, ctx, &start.query);
65    start_tmp.update(&tid, &start);
66    return 0;
67};
68
69int do_done(struct pt_regs *ctx) {
70    u64 pid_tgid = bpf_get_current_pid_tgid();
71    u32 pid = pid_tgid >> 32;
72    u32 tid = (u32)pid_tgid;
73    struct start_t *sp;
74
75    sp = start_tmp.lookup(&tid);
76    if (sp == 0) {
77        // missed tracing start
78        return 0;
79    }
80
81    // check if query exceeded our threshold
82    u64 delta = bpf_ktime_get_ns() - sp->ts;
83    if (delta >= """ + str(min_ns) + """) {
84        // populate and emit data struct
85        struct data_t data = {.pid = pid, .ts = sp->ts, .delta = delta};
86        bpf_probe_read_user(&data.query, sizeof(data.query), (void *)sp->query);
87        events.perf_submit(ctx, &data, sizeof(data));
88    }
89
90    start_tmp.delete(&tid);
91
92    return 0;
93};
94
95"""
96
97# enable USDT probe from given PID
98u = USDT(pid=pid)
99u.enable_probe(probe="query__start", fn_name="do_start")
100u.enable_probe(probe="query__done", fn_name="do_done")
101if debug:
102    print(u.get_text())
103    print(bpf_text)
104
105# initialize BPF
106b = BPF(text=bpf_text, usdt_contexts=[u])
107
108# header
109print("Tracing MySQL server queries for PID %d slower than %s ms..." % (pid,
110    min_ms_text))
111print("%-14s %-7s %8s %s" % ("TIME(s)", "PID", "MS", "QUERY"))
112
113# process event
114start = 0
115def print_event(cpu, data, size):
116    global start
117    event = b["events"].event(data)
118    if start == 0:
119        start = event.ts
120    print("%-14.6f %-7d %8.3f %s" % (float(event.ts - start) / 1000000000,
121        event.pid, float(event.delta) / 1000000, event.query))
122
123# loop with callback to print_event
124b["events"].open_perf_buffer(print_event, page_cnt=64)
125while 1:
126    try:
127        b.perf_buffer_poll()
128    except KeyboardInterrupt:
129        exit()
130