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Copy pathsoftirqs.py
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executable file
·150 lines (131 loc) · 3.95 KB
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#!/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.
# 03-Apr-2017 Sasha Goldshtein Migrated to kernel tracepoints.
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 {
u32 vec;
u64 slot;
} irq_key_t;
typedef struct account_val {
u64 ts;
u32 vec;
} account_val_t;
BPF_HASH(start, u32, account_val_t);
BPF_HASH(iptr, u32);
BPF_HISTOGRAM(dist, irq_key_t);
TRACEPOINT_PROBE(irq, softirq_entry)
{
u32 pid = bpf_get_current_pid_tgid();
account_val_t val = {};
val.ts = bpf_ktime_get_ns();
val.vec = args->vec;
start.update(&pid, &val);
return 0;
}
TRACEPOINT_PROBE(irq, softirq_exit)
{
u64 delta;
u32 vec;
u32 pid = bpf_get_current_pid_tgid();
account_val_t *valp;
irq_key_t key = {0};
// fetch timestamp and calculate delta
valp = start.lookup(&pid);
if (valp == 0) {
return 0; // missed start
}
delta = bpf_ktime_get_ns() - valp->ts;
vec = valp->vec;
// store as sum or histogram
STORE
start.delete(&pid);
return 0;
}
"""
# code substitutions
if args.dist:
bpf_text = bpf_text.replace('STORE',
'key.vec = vec; key.slot = bpf_log2l(delta / %d); ' % factor +
'dist.increment(key);')
else:
bpf_text = bpf_text.replace('STORE',
'key.vec = valp->vec; ' +
'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)
def vec_to_name(vec):
# copied from softirq_to_name() in kernel/softirq.c
# may need updates if new softirq handlers are added
return ["hi", "timer", "net_tx", "net_rx", "block", "irq_poll",
"tasklet", "sched", "hrtimer", "rcu"][vec]
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=vec_to_name)
else:
print("%-16s %11s" % ("SOFTIRQ", "TOTAL_" + label))
for k, v in sorted(dist.items(), key=lambda dist: dist[1].value):
print("%-16s %11d" % (vec_to_name(k.vec), v.value / factor))
dist.clear()
countdown -= 1
if exiting or countdown == 0:
exit()