blob: 71ee495360729f3df07daaa80e08e7932d9fd190 [file] [log] [blame]
#!/usr/bin/python
#
# cachestat Count cache kernel function calls.
# For Linux, uses BCC, eBPF. See .c file.
#
# USAGE: cachestat
# Taken from funccount by Brendan Gregg
# This is a rewrite of cachestat from perf to bcc
# https://github.com/brendangregg/perf-tools/blob/master/fs/cachestat
#
# Copyright (c) 2016 Allan McAleavy.
# Copyright (c) 2015 Brendan Gregg.
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 09-Sep-2015 Brendan Gregg Created this.
# 06-Nov-2015 Allan McAleavy
# 13-Jan-2016 Allan McAleavy run pep8 against program
from __future__ import print_function
from bcc import BPF
from time import sleep, strftime
import signal
import re
from sys import argv
# signal handler
def signal_ignore(signal, frame):
print()
# Function to gather data from /proc/meminfo
# return dictionary for quicker lookup of both values
def get_meminfo():
result = dict()
for line in open('/proc/meminfo'):
k = line.split(':', 3)
v = k[1].split()
result[k[0]] = int(v[0])
return result
# set global variables
rtaccess = 0
wtaccess = 0
mpa = 0
mbd = 0
apcl = 0
apd = 0
access = 0
misses = 0
rhits = 0
whits = 0
debug = 0
# args
def usage():
print("USAGE: %s [-T] [ interval [count] ]" % argv[0])
exit()
# arguments
interval = 5
count = -1
tstamp = 0
if len(argv) > 1:
if str(argv[1]) == '-T':
tstamp = 1
if len(argv) > 1 and tstamp == 0:
try:
if int(argv[1]) > 0:
interval = int(argv[1])
if len(argv) > 2:
if int(argv[2]) > 0:
count = int(argv[2])
except:
usage()
elif len(argv) > 2 and tstamp == 1:
try:
if int(argv[2]) > 0:
interval = int(argv[2])
if len(argv) >= 4:
if int(argv[3]) > 0:
count = int(argv[3])
except:
usage()
# load BPF program
bpf_text = """
#include <uapi/linux/ptrace.h>
struct key_t {
u64 ip;
};
BPF_HASH(counts, struct key_t);
int do_count(struct pt_regs *ctx) {
struct key_t key = {};
u64 zero = 0, *val;
u64 ip;
key.ip = ctx->ip;
val = counts.lookup_or_init(&key, &zero); // update counter
(*val)++;
return 0;
}
"""
b = BPF(text=bpf_text)
b.attach_kprobe(event="add_to_page_cache_lru", fn_name="do_count")
b.attach_kprobe(event="mark_page_accessed", fn_name="do_count")
b.attach_kprobe(event="account_page_dirtied", fn_name="do_count")
b.attach_kprobe(event="mark_buffer_dirty", fn_name="do_count")
# header
if tstamp:
print("%-8s " % "TIME", end="")
print("%8s %8s %8s %10s %10s %12s %10s" %
("HITS", "MISSES", "DIRTIES",
"READ_HIT%", "WRITE_HIT%", "BUFFERS_MB", "CACHED_MB"))
loop = 0
exiting = 0
while 1:
if count > 0:
loop += 1
if loop > count:
exit()
try:
sleep(interval)
except KeyboardInterrupt:
exiting = 1
# as cleanup can take many seconds, trap Ctrl-C:
signal.signal(signal.SIGINT, signal_ignore)
counts = b.get_table("counts")
for k, v in sorted(counts.items(), key=lambda counts: counts[1].value):
if re.match('mark_page_accessed', b.ksym(k.ip)) is not None:
mpa = v.value
if mpa < 0:
mpa = 0
if re.match('mark_buffer_dirty', b.ksym(k.ip)) is not None:
mbd = v.value
if mbd < 0:
mbd = 0
if re.match('add_to_page_cache_lru', b.ksym(k.ip)) is not None:
apcl = v.value
if apcl < 0:
apcl = 0
if re.match('account_page_dirtied', b.ksym(k.ip)) is not None:
apd = v.value
if apd < 0:
apd = 0
# access = total cache access incl. reads(mpa) and writes(mbd)
# misses = total of add to lru which we do when we write(mbd)
# and also the mark the page dirty(same as mbd)
access = (mpa + mbd)
misses = (apcl + apd)
# rtaccess is the read hit % during the sample period.
# wtaccess is the write hit % during the smaple period.
if mpa > 0:
rtaccess = float(mpa) / (access + misses)
if apcl > 0:
wtaccess = float(apcl) / (access + misses)
if wtaccess != 0:
whits = 100 * wtaccess
if rtaccess != 0:
rhits = 100 * rtaccess
if debug:
print("%d %d %d %d %d %d %f %f %d %d\n" %
(mpa, mbd, apcl, apd, access, misses,
rtaccess, wtaccess, rhits, whits))
counts.clear()
# Get memory info
mem = get_meminfo()
cached = int(mem["Cached"]) / 1024
buff = int(mem["Buffers"]) / 1024
if tstamp == 1:
print("%-8s " % strftime("%H:%M:%S"), end="")
print("%8d %8d %8d %9.1f%% %9.1f%% %12.0f %10.0f" %
(access, misses, mbd, rhits, whits, buff, cached))
mpa = 0
mbd = 0
apcl = 0
apd = 0
access = 0
misses = 0
rhits = 0
cached = 0
buff = 0
whits = 0
rtaccess = 0
wtaccess = 0
if exiting:
print("Detaching...")
exit()