contrib/gen_autofdo_event.py

   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 #
  29 import urllib2
  30 import sys
  31 import json
  32 import argparse
  33 import collections
  34
  35 baseurl = "https://download.01.org/perfmon"
  36
  37 target_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
  42 ap = argparse.ArgumentParser()
  43 ap.add_argument('--all', '-a', help='Print for all CPUs', action='store_true')
  44 ap.add_argument('--script', help='Generate shell script', action='store_true')
  45 args = ap.parse_args()
  46
  47 eventmap = collections.defaultdict(list)
  48
  49 def 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
  64 def 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
  83 if not args.all:
  84     cpu, model = get_cpu_str()
  85     if not cpu:
  86         sys.exit("Unknown CPU type")
  87
  88 url = baseurl + "/mapfile.csv"
  89 print >>sys.stderr, "Downloading", url
  90 u = urllib2.urlopen(url)
  91 found = 0
  92 cpufound = 0
  93 for 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)
 101 u.close()
 102
 103 if 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 --shell --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
 119 FLAGS=u
 120
 121 if [ "$1" = "--kernel" ] ; then
 122   FLAGS=k
 123   shift
 124 fi
 125 if [ "$1" = "--all" ] ; then
 126   FLAGS=uk
 127   shift
 128 fi
 129
 130 if ! grep -q Intel /proc/cpuinfo ; then
 131   echo >&2 "Only Intel CPUs supported"
 132   exit 1
 133 fi
 134
 135 if grep -q hypervisor /proc/cpuinfo ; then
 136   echo >&2 "Warning: branch profiling may not be functional in VMs"
 137 fi
 138
 139 case `egrep -q "^cpu family\s*: 6" /proc/cpuinfo &&
 140   egrep "^model\s*:" /proc/cpuinfo | head -n1` in'''
 141     for event, mod in eventmap.iteritems():
 142         for m in mod[:-1]:
 143             print "model*:\ %s|\\" % m
 144         print 'model*:\ %s) E="%s$FLAGS" ;;' % (mod[-1], event)
 145     print '''*)
 146 echo >&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
 151 if cpufound == 0 and not args.all:
 152     sys.exit('CPU %s not found' % cpu)
 153
 154 if found == 0:
 155     sys.exit('Branch event not found')