1#!/usr/bin/python
2# Generate Intel taken branches Linux perf event script for autofdo profiling.
3
4# Copyright (C) 2016 Free Software Foundation, Inc.
5#
6# GCC is free software; you can redistribute it and/or modify it under
7# the terms of the GNU General Public License as published by the Free
8# Software Foundation; either version 3, or (at your option) any later
9# version.
10#
11# GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12# WARRANTY; without even the implied warranty of MERCHANTABILITY or
13# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14# for more details.
15#
16# You should have received a copy of the GNU General Public License
17# along with GCC; see the file COPYING3.  If not see
18# <http://www.gnu.org/licenses/>.  */
19
20# Run it with perf record -b -e EVENT program ...
21# The Linux Kernel needs to support the PMU of the current CPU, and
22# It will likely not work in VMs.
23# Add --all to print for all cpus, otherwise for current cpu.
24# Add --script to generate shell script to run correct event.
25#
26# Requires internet (https) access. This may require setting up a proxy
27# with export https_proxy=...
28#
29import urllib2
30import sys
31import json
32import argparse
33import collections
34
35baseurl = "https://download.01.org/perfmon"
36
37target_events = (u'BR_INST_RETIRED.NEAR_TAKEN',
38                 u'BR_INST_EXEC.TAKEN',
39                 u'BR_INST_RETIRED.TAKEN_JCC',
40                 u'BR_INST_TYPE_RETIRED.COND_TAKEN')
41
42ap = argparse.ArgumentParser()
43ap.add_argument('--all', '-a', help='Print for all CPUs', action='store_true')
44ap.add_argument('--script', help='Generate shell script', action='store_true')
45args = ap.parse_args()
46
47eventmap = collections.defaultdict(list)
48
49def get_cpu_str():
50    with open('/proc/cpuinfo', 'r') as c:
51        vendor, fam, model = None, None, None
52        for j in c:
53            n = j.split()
54            if n[0] == 'vendor_id':
55                vendor = n[2]
56            elif n[0] == 'model' and n[1] == ':':
57                model = int(n[2])
58            elif n[0] == 'cpu' and n[1] == 'family':
59                fam = int(n[3])
60            if vendor and fam and model:
61                return "%s-%d-%X" % (vendor, fam, model), model
62    return None, None
63
64def find_event(eventurl, model):
65    print >>sys.stderr, "Downloading", eventurl
66    u = urllib2.urlopen(eventurl)
67    events = json.loads(u.read())
68    u.close()
69
70    found = 0
71    for j in events:
72        if j[u'EventName'] in target_events:
73            event = "cpu/event=%s,umask=%s/" % (j[u'EventCode'], j[u'UMask'])
74            if u'PEBS' in j and j[u'PEBS'] > 0:
75                event += "p"
76            if args.script:
77                eventmap[event].append(model)
78            else:
79                print j[u'EventName'], "event for model", model, "is", event
80            found += 1
81    return found
82
83if not args.all:
84    cpu, model = get_cpu_str()
85    if not cpu:
86        sys.exit("Unknown CPU type")
87
88url = baseurl + "/mapfile.csv"
89print >>sys.stderr, "Downloading", url
90u = urllib2.urlopen(url)
91found = 0
92cpufound = 0
93for j in u:
94    n = j.rstrip().split(',')
95    if len(n) >= 4 and (args.all or n[0] == cpu) and n[3] == "core":
96        if args.all:
97            vendor, fam, model = n[0].split("-")
98            model = int(model, 16)
99        cpufound += 1
100        found += find_event(baseurl + n[2], model)
101u.close()
102
103if args.script:
104    print '''#!/bin/sh
105# Profile workload for gcc profile feedback (autofdo) using Linux perf.
106# Auto generated. To regenerate for new CPUs run
107# contrib/gen_autofdo_event.py --script --all in gcc source
108
109# usages:
110# gcc-auto-profile program             (profile program and children)
111# gcc-auto-profile -a sleep X          (profile all for X secs, may need root)
112# gcc-auto-profile -p PID sleep X      (profile PID)
113# gcc-auto-profile --kernel -a sleep X (profile kernel)
114# gcc-auto-profile --all -a sleep X    (profile kernel and user space)
115
116# Identify branches taken event for CPU.
117#
118
119FLAGS=u
120
121if [ "$1" = "--kernel" ] ; then
122  FLAGS=k
123  shift
124fi
125if [ "$1" = "--all" ] ; then
126  FLAGS=uk
127  shift
128fi
129
130if ! grep -q Intel /proc/cpuinfo ; then
131  echo >&2 "Only Intel CPUs supported"
132  exit 1
133fi
134
135if grep -q hypervisor /proc/cpuinfo ; then
136  echo >&2 "Warning: branch profiling may not be functional in VMs"
137fi
138
139case `egrep -q "^cpu family\s*: 6" /proc/cpuinfo &&
140  egrep "^model\s*:" /proc/cpuinfo | head -n1` in'''
141    for event, mod in eventmap.iteritems():
142        for m in mod[:-1]:
143            print "model*:\ %s|\\" % m
144        print 'model*:\ %s) E="%s$FLAGS" ;;' % (mod[-1], event)
145    print '''*)
146echo >&2 "Unknown CPU. Run contrib/gen_autofdo_event.py --all --script to update script."
147	exit 1 ;;'''
148    print "esac"
149    print 'exec perf record -e $E -b "$@"'
150
151if cpufound == 0 and not args.all:
152    sys.exit('CPU %s not found' % cpu)
153
154if found == 0:
155    sys.exit('Branch event not found')
156