xref: /aosp_15_r20/external/bcc/tools/drsnoop.py (revision 387f9dfdfa2baef462e92476d413c7bc2470293e) 
1#!/usr/bin/env python
2# @lint-avoid-python-3-compatibility-imports
3#
4# drsnoop  Trace direct reclaim and print details including issuing PID.
5#       For Linux, uses BCC, eBPF.
6#
7# This uses in-kernel eBPF maps to cache process details (PID and comm) by
8# direct reclaim begin, as well as a starting timestamp for calculating
9# latency.
10#
11# Copyright (c) 2019 Wenbo Zhang
12# Licensed under the Apache License, Version 2.0 (the "License")
13#
14# 20-Feb-2019   Wenbo Zhang   Created this.
15# 09-Mar-2019   Wenbo Zhang   Updated for show sys mem info.
16
17from __future__ import print_function
18from bcc import ArgString, BPF
19import argparse
20from datetime import datetime, timedelta
21import os
22import math
23import sys
24
25# symbols
26kallsyms = "/proc/kallsyms"
27
28# arguments
29examples = """examples:
30    ./drsnoop           # trace all direct reclaim
31    ./drsnoop -T        # include timestamps
32    ./drsnoop -U        # include UID
33    ./drsnoop -P 181    # only trace PID 181
34    ./drsnoop -t 123    # only trace TID 123
35    ./drsnoop -u 1000   # only trace UID 1000
36    ./drsnoop -d 10     # trace for 10 seconds only
37    ./drsnoop -n main   # only print process names containing "main"
38"""
39parser = argparse.ArgumentParser(
40    description="Trace direct reclaim",
41    formatter_class=argparse.RawDescriptionHelpFormatter,
42    epilog=examples)
43parser.add_argument("-T", "--timestamp", action="store_true",
44                    help="include timestamp on output")
45parser.add_argument("-U", "--print-uid", action="store_true",
46                    help="print UID column")
47parser.add_argument("-p", "--pid",
48                    help="trace this PID only")
49parser.add_argument("-t", "--tid",
50                    help="trace this TID only")
51parser.add_argument("-u", "--uid",
52                    help="trace this UID only")
53parser.add_argument("-d", "--duration",
54                    help="total duration of trace in seconds")
55parser.add_argument("-n", "--name",
56                    type=ArgString,
57                    help="only print process names containing this name")
58parser.add_argument("-v", "--verbose", action="store_true",
59                    help="show system memory state")
60parser.add_argument("--ebpf", action="store_true",
61                    help=argparse.SUPPRESS)
62args = parser.parse_args()
63debug = 0
64if args.duration:
65    args.duration = timedelta(seconds=int(args.duration))
66
67
68# vm_stat
69vm_stat_addr = ''
70with open(kallsyms) as syms:
71    for line in syms:
72        (addr, size, name) = line.rstrip().split(" ", 2)
73        name = name.split("\t")[0]
74        if name == "vm_stat":
75            vm_stat_addr = "0x" + addr
76            break
77        if name == "vm_zone_stat":
78            vm_stat_addr = "0x" + addr
79            break
80    if vm_stat_addr == '':
81        print("ERROR: no vm_stat or vm_zone_stat in /proc/kallsyms. Exiting.")
82        print("HINT: the kernel should be built with CONFIG_KALLSYMS_ALL.")
83        exit()
84
85NR_FREE_PAGES = 0
86
87PAGE_SIZE = os.sysconf("SC_PAGE_SIZE")
88PAGE_SHIFT = int(math.log(PAGE_SIZE) / math.log(2))
89
90def K(x):
91    return x << (PAGE_SHIFT - 10)
92
93# load BPF program
94bpf_text = """
95#include <uapi/linux/ptrace.h>
96#include <linux/sched.h>
97#include <linux/mmzone.h>
98
99struct val_t {
100    u64 id;
101    u64 ts; // start time
102    char name[TASK_COMM_LEN];
103    u64 vm_stat[NR_VM_ZONE_STAT_ITEMS];
104};
105
106struct data_t {
107    u64 id;
108    u32 uid;
109    u64 nr_reclaimed;
110    u64 delta;
111    u64 ts;    // end time
112    char name[TASK_COMM_LEN];
113    u64 vm_stat[NR_VM_ZONE_STAT_ITEMS];
114};
115
116BPF_HASH(start, u64, struct val_t);
117BPF_PERF_OUTPUT(events);
118
119TRACEPOINT_PROBE(vmscan, mm_vmscan_direct_reclaim_begin) {
120    struct val_t val = {};
121    u64 id = bpf_get_current_pid_tgid();
122    u32 pid = id >> 32; // PID is higher part
123    u32 tid = id;       // Cast and get the lower part
124    u32 uid = bpf_get_current_uid_gid();
125    u64 ts;
126
127    PID_TID_FILTER
128    UID_FILTER
129    if (bpf_get_current_comm(&val.name, sizeof(val.name)) == 0) {
130        val.id = id;
131        val.ts = bpf_ktime_get_ns();
132        bpf_probe_read_kernel(&val.vm_stat, sizeof(val.vm_stat), (const void *)%s);
133        start.update(&id, &val);
134    }
135    return 0;
136}
137
138TRACEPOINT_PROBE(vmscan, mm_vmscan_direct_reclaim_end) {
139    u64 id = bpf_get_current_pid_tgid();
140    struct val_t *valp;
141    struct data_t data = {};
142    u64 ts = bpf_ktime_get_ns();
143
144    valp = start.lookup(&id);
145    if (valp == NULL) {
146        // missed entry
147        return 0;
148    }
149
150    data.delta = ts - valp->ts;
151    data.ts = ts / 1000;
152    data.id = valp->id;
153    data.uid = bpf_get_current_uid_gid();
154    bpf_probe_read_kernel(&data.name, sizeof(data.name), valp->name);
155    bpf_probe_read_kernel(&data.vm_stat, sizeof(data.vm_stat), valp->vm_stat);
156    data.nr_reclaimed = args->nr_reclaimed;
157
158    events.perf_submit(args, &data, sizeof(data));
159    start.delete(&id);
160
161    return 0;
162}
163""" % vm_stat_addr
164
165if args.tid:  # TID trumps PID
166    bpf_text = bpf_text.replace('PID_TID_FILTER',
167                                'if (tid != %s) { return 0; }' % args.tid)
168elif args.pid:
169    bpf_text = bpf_text.replace('PID_TID_FILTER',
170                                'if (pid != %s) { return 0; }' % args.pid)
171else:
172    bpf_text = bpf_text.replace('PID_TID_FILTER', '')
173if args.uid:
174    bpf_text = bpf_text.replace('UID_FILTER',
175                                'if (uid != %s) { return 0; }' % args.uid)
176else:
177    bpf_text = bpf_text.replace('UID_FILTER', '')
178if debug or args.ebpf:
179    print(bpf_text)
180    if args.ebpf:
181        exit()
182
183# initialize BPF
184b = BPF(text=bpf_text)
185
186initial_ts = 0
187
188# header
189if args.timestamp:
190    print("%-14s" % ("TIME(s)"), end="")
191if args.print_uid:
192    print("%-6s" % ("UID"), end="")
193print("%-14s %-6s %8s %5s" %
194      ("COMM", "TID" if args.tid else "PID", "LAT(ms)", "PAGES"), end="")
195if args.verbose:
196    print("%10s" % ("FREE(KB)"))
197else:
198    print("")
199
200# process event
201def print_event(cpu, data, size):
202    event = b["events"].event(data)
203
204    global initial_ts
205
206    if not initial_ts:
207        initial_ts = event.ts
208
209    if args.name and bytes(args.name) not in event.name:
210        return
211
212    if args.timestamp:
213        delta = event.ts - initial_ts
214        print("%-14.9f" % (float(delta) / 1000000), end="")
215
216    if args.print_uid:
217        print("%-6d" % event.uid, end="")
218
219    print("%-14.14s %-6s %8.2f %5d" %
220          (event.name.decode('utf-8', 'replace'),
221           event.id & 0xffffffff if args.tid else event.id >> 32,
222           float(event.delta) / 1000000, event.nr_reclaimed), end="")
223    if args.verbose:
224        print("%10d" % K(event.vm_stat[NR_FREE_PAGES]))
225    else:
226        print("")
227
228    sys.stdout.flush()
229
230
231# loop with callback to print_event
232b["events"].open_perf_buffer(print_event, page_cnt=64)
233start_time = datetime.now()
234while not args.duration or datetime.now() - start_time < args.duration:
235    try:
236        b.perf_buffer_poll()
237    except KeyboardInterrupt:
238        exit()
239