blob: f1911b094e08f98a95b320bd8ff78b04b686ed18 [file] [log] [blame]
#!/usr/bin/python
# @lint-avoid-python-3-compatibility-imports
#
# slabratetop Summarize kmem_cache_alloc() calls.
# For Linux, uses BCC, eBPF.
#
# USAGE: slabratetop [-h] [-C] [-r MAXROWS] [interval] [count]
#
# This uses in-kernel BPF maps to store cache summaries for efficiency.
#
# SEE ALSO: slabtop(1), which shows the cache volumes.
#
# Copyright 2016 Netflix, Inc.
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 15-Oct-2016 Brendan Gregg Created this.
from __future__ import print_function
from bcc import BPF
from bcc.utils import printb
from time import sleep, strftime
import argparse
import signal
from subprocess import call
# arguments
examples = """examples:
./slabratetop # kmem_cache_alloc() top, 1 second refresh
./slabratetop -C # don't clear the screen
./slabratetop 5 # 5 second summaries
./slabratetop 5 10 # 5 second summaries, 10 times only
"""
parser = argparse.ArgumentParser(
description="Kernel SLAB/SLUB memory cache allocation rate top",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=examples)
parser.add_argument("-C", "--noclear", action="store_true",
help="don't clear the screen")
parser.add_argument("-r", "--maxrows", default=20,
help="maximum rows to print, default 20")
parser.add_argument("interval", nargs="?", default=1,
help="output interval, in seconds")
parser.add_argument("count", nargs="?", default=99999999,
help="number of outputs")
parser.add_argument("--ebpf", action="store_true",
help=argparse.SUPPRESS)
args = parser.parse_args()
interval = int(args.interval)
countdown = int(args.count)
maxrows = int(args.maxrows)
clear = not int(args.noclear)
debug = 0
# linux stats
loadavg = "/proc/loadavg"
# signal handler
def signal_ignore(signal, frame):
print()
# define BPF program
bpf_text = """
#include <uapi/linux/ptrace.h>
#include <linux/mm.h>
#include <linux/slab.h>
#ifdef CONFIG_SLUB
#include <linux/slub_def.h>
#else
#include <linux/slab_def.h>
#endif
#define CACHE_NAME_SIZE 32
// the key for the output summary
struct info_t {
char name[CACHE_NAME_SIZE];
};
// the value of the output summary
struct val_t {
u64 count;
u64 size;
};
BPF_HASH(counts, struct info_t, struct val_t);
int kprobe__kmem_cache_alloc(struct pt_regs *ctx, struct kmem_cache *cachep)
{
struct info_t info = {};
bpf_probe_read(&info.name, sizeof(info.name), (void *)cachep->name);
struct val_t *valp, zero = {};
valp = counts.lookup_or_init(&info, &zero);
valp->count++;
valp->size += cachep->size;
return 0;
}
"""
if debug or args.ebpf:
print(bpf_text)
if args.ebpf:
exit()
# initialize BPF
b = BPF(text=bpf_text)
print('Tracing... Output every %d secs. Hit Ctrl-C to end' % interval)
# output
exiting = 0
while 1:
try:
sleep(interval)
except KeyboardInterrupt:
exiting = 1
# header
if clear:
call("clear")
else:
print()
with open(loadavg) as stats:
print("%-8s loadavg: %s" % (strftime("%H:%M:%S"), stats.read()))
print("%-32s %6s %10s" % ("CACHE", "ALLOCS", "BYTES"))
# by-TID output
counts = b.get_table("counts")
line = 0
for k, v in reversed(sorted(counts.items(),
key=lambda counts: counts[1].size)):
printb(b"%-32s %6d %10d" % (k.name, v.count, v.size))
line += 1
if line >= maxrows:
break
counts.clear()
countdown -= 1
if exiting or countdown == 0:
print("Detaching...")
exit()