Repository navigation
Expand file tree
/
Copy pathsoftirqs.py
More file actions
executable file
·146 lines (129 loc) · 4.13 KB
/
Copy pathsoftirqs.py
File metadata and controls
executable file
·146 lines (129 loc) · 4.13 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
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
#!/usr/bin/python
# @lint-avoid-python-3-compatibility-imports
#
# softirqs Summarize soft IRQ (interrupt) event time.
# For Linux, uses BCC, eBPF.
#
# USAGE: softirqs [-h] [-T] [-N] [-d] [interval] [count]
#
# Copyright (c) 2015 Brendan Gregg.
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 20-Oct-2015 Brendan Gregg Created this.
from __future__ import print_function
from bcc import BPF
from time import sleep, strftime
import argparse
# arguments
examples = """examples:
./softirqs # sum soft irq event time
./softirqs -d # show soft irq event time as histograms
./softirqs 1 10 # print 1 second summaries, 10 times
./softirqs -NT 1 # 1s summaries, nanoseconds, and timestamps
"""
parser = argparse.ArgumentParser(
description="Summarize soft irq event time as histograms",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=examples)
parser.add_argument("-T", "--timestamp", action="store_true",
help="include timestamp on output")
parser.add_argument("-N", "--nanoseconds", action="store_true",
help="output in nanoseconds")
parser.add_argument("-d", "--dist", action="store_true",
help="show distributions as histograms")
parser.add_argument("interval", nargs="?", default=99999999,
help="output interval, in seconds")
parser.add_argument("count", nargs="?", default=99999999,
help="number of outputs")
args = parser.parse_args()
countdown = int(args.count)
if args.nanoseconds:
factor = 1
label = "nsecs"
else:
factor = 1000
label = "usecs"
debug = 0
# define BPF program
bpf_text = """
#include <uapi/linux/ptrace.h>
typedef struct irq_key {
u64 ip;
u64 slot;
} irq_key_t;
BPF_HASH(start, u32);
BPF_HASH(iptr, u32);
BPF_HISTOGRAM(dist, irq_key_t);
// time IRQ
int trace_start(struct pt_regs *ctx)
{
u32 pid = bpf_get_current_pid_tgid();
u64 ip = PT_REGS_IP(ctx), ts = bpf_ktime_get_ns();
start.update(&pid, &ts);
iptr.update(&pid, &ip);
return 0;
}
int trace_completion(struct pt_regs *ctx)
{
u64 *tsp, delta, ip, *ipp;
u32 pid = bpf_get_current_pid_tgid();
// fetch timestamp and calculate delta
tsp = start.lookup(&pid);
ipp = iptr.lookup(&pid);
if (tsp == 0 || ipp == 0) {
return 0; // missed start
}
delta = bpf_ktime_get_ns() - *tsp;
ip = *ipp;
// store as sum or histogram
STORE
start.delete(&pid);
iptr.delete(&pid);
return 0;
}
"""
# code substitutions
if args.dist:
bpf_text = bpf_text.replace('STORE',
'irq_key_t key = {.ip = ip, .slot = bpf_log2l(delta)};' +
'dist.increment(key);')
else:
bpf_text = bpf_text.replace('STORE',
'irq_key_t key = {.ip = ip, .slot = 0 /* ignore */};' +
'u64 zero = 0, *vp = dist.lookup_or_init(&key, &zero);' +
'(*vp) += delta;')
if debug:
print(bpf_text)
# load BPF program
b = BPF(text=bpf_text)
# this should really use irq:softirq_entry/exit tracepoints; for now the
# soft irq functions are individually traced (search your kernel for
# open_softirq() calls, and adjust the following list as needed).
for softirqfunc in ("blk_iopoll_softirq", "blk_done_softirq",
"rcu_process_callbacks", "run_rebalance_domains", "tasklet_action",
"tasklet_hi_action", "run_timer_softirq", "net_tx_action",
"net_rx_action"):
b.attach_kprobe(event=softirqfunc, fn_name="trace_start")
b.attach_kretprobe(event=softirqfunc, fn_name="trace_completion")
print("Tracing soft irq event time... Hit Ctrl-C to end.")
# output
exiting = 0 if args.interval else 1
dist = b.get_table("dist")
while (1):
try:
sleep(int(args.interval))
except KeyboardInterrupt:
exiting = 1
print()
if args.timestamp:
print("%-8s\n" % strftime("%H:%M:%S"), end="")
if args.dist:
dist.print_log2_hist(label, "softirq", section_print_fn=b.ksym)
else:
print("%-26s %11s" % ("SOFTIRQ", "TOTAL_" + label))
for k, v in sorted(dist.items(), key=lambda dist: dist[1].value):
print("%-26s %11d" % (b.ksym(k.ip), v.value / factor))
dist.clear()
countdown -= 1
if exiting or countdown == 0:
exit()