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#!/usr/bin/python
# Generate Intel taken branches Linux perf event script for autofdo profiling.
# Copyright (C) 2016 Free Software Foundation, Inc.
#
# GCC is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 3, or (at your option) any later
# version.
#
# GCC is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License
# along with GCC; see the file COPYING3. If not see
# <http://www.gnu.org/licenses/>. */
# Run it with perf record -b -e EVENT program ...
# The Linux Kernel needs to support the PMU of the current CPU, and
# It will likely not work in VMs.
# Add --all to print for all cpus, otherwise for current cpu.
# Add --script to generate shell script to run correct event.
#
# Requires internet (https) access. This may require setting up a proxy
# with export https_proxy=...
#
import urllib2
import sys
import json
import argparse
import collections
baseurl = "https://download.01.org/perfmon"
target_events = (u'BR_INST_RETIRED.NEAR_TAKEN',
u'BR_INST_EXEC.TAKEN',
u'BR_INST_RETIRED.TAKEN_JCC',
u'BR_INST_TYPE_RETIRED.COND_TAKEN')
ap = argparse.ArgumentParser()
ap.add_argument('--all', '-a', help='Print for all CPUs', action='store_true')
ap.add_argument('--script', help='Generate shell script', action='store_true')
args = ap.parse_args()
eventmap = collections.defaultdict(list)
def get_cpu_str():
with open('/proc/cpuinfo', 'r') as c:
vendor, fam, model = None, None, None
for j in c:
n = j.split()
if n[0] == 'vendor_id':
vendor = n[2]
elif n[0] == 'model' and n[1] == ':':
model = int(n[2])
elif n[0] == 'cpu' and n[1] == 'family':
fam = int(n[3])
if vendor and fam and model:
return "%s-%d-%X" % (vendor, fam, model), model
return None, None
def find_event(eventurl, model):
print >>sys.stderr, "Downloading", eventurl
u = urllib2.urlopen(eventurl)
events = json.loads(u.read())
u.close()
found = 0
for j in events:
if j[u'EventName'] in target_events:
event = "cpu/event=%s,umask=%s/" % (j[u'EventCode'], j[u'UMask'])
if u'PEBS' in j and j[u'PEBS'] > 0:
event += "p"
if args.script:
eventmap[event].append(model)
else:
print j[u'EventName'], "event for model", model, "is", event
found += 1
return found
if not args.all:
cpu, model = get_cpu_str()
if not cpu:
sys.exit("Unknown CPU type")
url = baseurl + "/mapfile.csv"
print >>sys.stderr, "Downloading", url
u = urllib2.urlopen(url)
found = 0
cpufound = 0
for j in u:
n = j.rstrip().split(',')
if len(n) >= 4 and (args.all or n[0] == cpu) and n[3] == "core":
if args.all:
vendor, fam, model = n[0].split("-")
model = int(model, 16)
cpufound += 1
found += find_event(baseurl + n[2], model)
u.close()
if args.script:
print '''#!/bin/sh
# Profile workload for gcc profile feedback (autofdo) using Linux perf.
# Auto generated. To regenerate for new CPUs run
# contrib/gen_autofdo_event.py --script --all in gcc source
# usages:
# gcc-auto-profile program (profile program and children)
# gcc-auto-profile -a sleep X (profile all for X secs, may need root)
# gcc-auto-profile -p PID sleep X (profile PID)
# gcc-auto-profile --kernel -a sleep X (profile kernel)
# gcc-auto-profile --all -a sleep X (profile kernel and user space)
# Identify branches taken event for CPU.
#
FLAGS=u
if [ "$1" = "--kernel" ] ; then
FLAGS=k
shift
fi
if [ "$1" = "--all" ] ; then
FLAGS=uk
shift
fi
if ! grep -q Intel /proc/cpuinfo ; then
echo >&2 "Only Intel CPUs supported"
exit 1
fi
if grep -q hypervisor /proc/cpuinfo ; then
echo >&2 "Warning: branch profiling may not be functional in VMs"
fi
case `egrep -q "^cpu family\s*: 6" /proc/cpuinfo &&
egrep "^model\s*:" /proc/cpuinfo | head -n1` in'''
for event, mod in eventmap.iteritems():
for m in mod[:-1]:
print "model*:\ %s|\\" % m
print 'model*:\ %s) E="%s$FLAGS" ;;' % (mod[-1], event)
print '''*)
echo >&2 "Unknown CPU. Run contrib/gen_autofdo_event.py --all --script to update script."
exit 1 ;;'''
print "esac"
print 'exec perf record -e $E -b "$@"'
if cpufound == 0 and not args.all:
sys.exit('CPU %s not found' % cpu)
if found == 0:
sys.exit('Branch event not found')
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