bcc/tools/old/wakeuptime.py at tag_v0.6.0 · devel-hm/bcc

Repository navigation

History

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

1 8000 17

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

#!/usr/bin/python

# wakeuptime Summarize sleep to wakeup time by waker kernel stack

# For Linux, uses BCC, eBPF.

# USAGE: wakeuptime [-h] [-u] [-p PID] [-v] [-f] [duration]

# The current implementation uses an unrolled loop for x86_64, and was written

# as a proof of concept. This implementation should be replaced in the future

# with an appropriate bpf_ call, when available.

# Currently limited to a stack trace depth of 21 (maxdepth + 1).

# Licensed under the Apache License, Version 2.0 (the "License")

# 14-Jan-2016 Brendan Gregg Created this.

from __future__ import print_function

from bcc import BPF

from time import sleep, strftime

import argparse

import signal

# arguments

examples = """examples:

./wakeuptime # trace blocked time with waker stacks

./wakeuptime 5 # trace for 5 seconds only

./wakeuptime -f 5 # 5 seconds, and output in folded format

./wakeuptime -u # don't include kernel threads (user only)

./wakeuptime -p 185 # trace fo PID 185 only

"""

parser = argparse.ArgumentParser(

description="Summarize sleep to wakeup time by waker kernel stack",

formatter_class=argparse.RawDescriptionHelpFormatter,

epilog=examples)

parser.add_argument("-u", "--useronly", action="store_true",

help="user threads only (no kernel threads)")

parser.add_argument("-p", "--pid",

help="trace this PID only")

parser.add_argument("-v", "--verbose", action="store_true",

help="show raw addresses")

parser.add_argument("-f", "--folded", action="store_true",

help="output folded format")

parser.add_argument("duration", nargs="?", default=99999999,

help="duration of trace, in seconds")

args = parser.parse_args()

folded = args.folded

duration = int(args.duration)

debug = 0

maxdepth = 20 # and MAXDEPTH

if args.pid and args.useronly:

print("ERROR: use either -p or -u.")

exit()

# signal handler

def signal_ignore(signal, frame):

print()

# define BPF program

bpf_text = """

#include <uapi/linux/ptrace.h>

#include <linux/sched.h>

#define MAXDEPTH 20

#define MINBLOCK_US 1

struct key_t {

char waker[TASK_COMM_LEN];

char target[TASK_COMM_LEN];

// Skip saving the ip

u64 ret[MAXDEPTH];

};

BPF_HASH(counts, struct key_t);

BPF_HASH(start, u32);

static u64 get_frame(u64 *bp) {

if (*bp) {

// The following stack walker is x86_64/arm64 specific

u64 ret = 0;

if (bpf_probe_read(&ret, sizeof(ret), (void *)(*bp+8)))

return 0;

if (bpf_probe_read(bp, sizeof(*bp), (void *)*bp))

return 0;

#ifdef __x86_64__

if (ret < __START_KERNEL_map)

#elif __aarch64__

if (ret < VA_START)

#else

#error "Unsupported architecture for stack walker"

#endif

return 0;

return ret;

}

return 0;

}

int offcpu(struct pt_regs *ctx) {

u32 pid = bpf_get_current_pid_tgid();

u64 ts = bpf_ktime_get_ns();

// XXX: should filter here too, but need task_struct

start.update(&pid, &ts);

return 0;

}

int waker(struct pt_regs *ctx, struct task_struct *p) {

u32 pid = p->pid;

u64 delta, *tsp, ts;

tsp = start.lookup(&pid);

if (tsp == 0)

return 0; // missed start

start.delete(&pid);

if (FILTER)

return 0;

// calculate delta time

delta = bpf_ktime_get_ns() - *tsp;

delta = delta / 1000;

if (delta < MINBLOCK_US)

return 0;

struct key_t key = {};

u64 zero = 0, *val, bp = 0;

int depth = 0;

bpf_probe_read(&key.target, sizeof(key.target), p->comm);

bpf_get_current_comm(&key.waker, sizeof(key.waker));

bp = PT_REGS_FP(ctx);

// unrolled loop (MAXDEPTH):

if (!(key.ret[depth++] = get_frame(&bp))) goto out;

out:

val = counts.lookup_or_init(&key, &zero);

(*val) += delta;

return 0;

}

"""

if args.pid:

filter = 'pid != %s' % args.pid

elif args.useronly:

filter = 'p->flags & PF_KTHREAD'

else:

filter = '0'

bpf_text = bpf_text.replace('FILTER', filter)

if debug:

print(bpf_text)

# initialize BPF

b = BPF(text=bpf_text)

b.attach_kprobe(event="schedule", fn_name="offcpu")

b.attach_kprobe(event="try_to_wake_up", fn_name="waker")

matched = b.num_open_kprobes()

if matched == 0:

print("0 functions traced. Exiting.")

exit()

# header

if not folded:

print("Tracing blocked time (us) by kernel stack", end="")

if duration < 99999999:

print(" for %d secs." % duration)

else:

print("... Hit Ctrl-C to end.")

# output

while (1):

try:

sleep(duration)

except KeyboardInterrupt:

# as cleanup can take many seconds, trap Ctrl-C:

signal.signal(signal.SIGINT, signal_ignore)

if not folded:

print()

counts = b.get_table("counts")

for k, v in sorted(counts.items(), key=lambda counts: counts[1].value):

if folded:

# print folded stack output

line = k.waker.decode() + ";"

for i in reversed(range(0, maxdepth)):

if k.ret[i] == 0:

continue

line = line + b.ksym(k.ret[i])

if i != 0:

line = line + ";"

print("%s;%s %d" % (line, k.target.decode(), v.value))

else:

# print default multi-line stack output

print(" %-16s %s" % ("target:", k.target.decode()))

for i in range(0, maxdepth):

if k.ret[i] == 0:

break

print(" %-16x %s" % (k.ret[i],

b.ksym(k.ret[i])))

print(" %-16s %s" % ("waker:", k.waker.decode()))

print(" %d\n" % v.value)

counts.clear()

if not folded:

print("Detaching...")

exit()

FilesExpand file tree

wakeuptime.py

Latest commit

History

wakeuptime.py

File metadata and controls