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yaml
---
r: 218686
b: refs/heads/master
c: 00204c3
h: refs/heads/master
v: v3
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Arnaldo Carvalho de Melo committed Oct 26, 2010
1 parent 1d61a02 commit 6821c22
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Showing 5 changed files with 75 additions and 1 deletion.
2 changes: 1 addition & 1 deletion [refs]
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---
refs/heads/master: 22d0594b31046793dfb58b7ce866d7cb0a9862e5
refs/heads/master: 00204c3396469f407bac56e1475ea16e4a279b13
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import errno, os

FUTEX_WAIT = 0
FUTEX_WAKE = 1
FUTEX_PRIVATE_FLAG = 128
FUTEX_CLOCK_REALTIME = 256
FUTEX_CMD_MASK = ~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME)

NSECS_PER_SEC = 1000000000

def avg(total, n):
Expand All @@ -26,6 +32,18 @@ def nsecs_str(nsecs):
str = "%5u.%09u" % (nsecs_secs(nsecs), nsecs_nsecs(nsecs)),
return str

def add_stats(dict, key, value):
if not dict.has_key(key):
dict[key] = (value, value, value, 1)
else:
min, max, avg, count = dict[key]
if value < min:
min = value
if value > max:
max = value
avg = (avg + value) / 2
dict[key] = (min, max, avg, count + 1)

def clear_term():
print("\x1b[H\x1b[2J")

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2 changes: 2 additions & 0 deletions trunk/tools/perf/scripts/python/bin/futex-contention-record
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#!/bin/bash
perf record -a -e syscalls:sys_enter_futex -e syscalls:sys_exit_futex $@
4 changes: 4 additions & 0 deletions trunk/tools/perf/scripts/python/bin/futex-contention-report
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#!/bin/bash
# description: futext contention measurement

perf trace $@ -s "$PERF_EXEC_PATH"/scripts/python/futex-contention.py
50 changes: 50 additions & 0 deletions trunk/tools/perf/scripts/python/futex-contention.py
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# futex contention
# (c) 2010, Arnaldo Carvalho de Melo <acme@redhat.com>
# Licensed under the terms of the GNU GPL License version 2
#
# Translation of:
#
# http://sourceware.org/systemtap/wiki/WSFutexContention
#
# to perf python scripting.
#
# Measures futex contention

import os, sys
sys.path.append(os.environ['PERF_EXEC_PATH'] + '/scripts/python/Perf-Trace-Util/lib/Perf/Trace')
from Util import *

process_names = {}
thread_thislock = {}
thread_blocktime = {}

lock_waits = {} # long-lived stats on (tid,lock) blockage elapsed time
process_names = {} # long-lived pid-to-execname mapping

def syscalls__sys_enter_futex(event, ctxt, cpu, s, ns, tid, comm,
nr, uaddr, op, val, utime, uaddr2, val3):
cmd = op & FUTEX_CMD_MASK
if cmd != FUTEX_WAIT:
return # we don't care about originators of WAKE events

process_names[tid] = comm
thread_thislock[tid] = uaddr
thread_blocktime[tid] = nsecs(s, ns)

def syscalls__sys_exit_futex(event, ctxt, cpu, s, ns, tid, comm,
nr, ret):
if thread_blocktime.has_key(tid):
elapsed = nsecs(s, ns) - thread_blocktime[tid]
add_stats(lock_waits, (tid, thread_thislock[tid]), elapsed)
del thread_blocktime[tid]
del thread_thislock[tid]

def trace_begin():
print "Press control+C to stop and show the summary"

def trace_end():
for (tid, lock) in lock_waits:
min, max, avg, count = lock_waits[tid, lock]
print "%s[%d] lock %x contended %d times, %d avg ns" % \
(process_names[tid], tid, lock, count, avg)

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