ocperf.py

#!/usr/bin/env python
# Copyright (c) 2011-2015, Intel Corporation
# Author: Andi Kleen
#
# This program is free software; you can redistribute it and/or modify it
# under the terms and conditions of the GNU General Public License,
# version 2, as published by the Free Software Foundation.
#
# This program is distributed in the hope 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.
#
# wrapper for perf for using named events and events with additional MSRs.
# syntax is like perf, except Intel events are listed and can be specified
# 
# or library for other python program to convert intel event names to
# perf/raw format
#
# Features:
# - map intel events to raw perf events
# - enable disable workarounds for specific events
# - resolve uncore events
# - handle offcore event on older kernels
# For the later must run as root and only as a single instance per machine 
# Normal events (mainly not OFFCORE) can be handled unprivileged 
# For events you can specify additional intel names from the list
#
# env variables:
# PERF=... perf binary to use (default "perf")
# EVENTMAP=eventmap
# OFFCORE=eventmap
# UNCORE=eventmap
# eventmap is a path name to a json file
# When eventmap is not specified, look in ~/.events
# The eventmap is automatically downloaded there
# eventmap can be also a CPU specified (GenuineIntel-FAMILY-MODEL, like GenuineIntel-06-37)
#
# Special arguments:
# --no-period   Never add a period
# --print       only print
# --force-download Force event list download
import sys
import os
import subprocess
import json
import re
import copy
import textwrap
import pipes
import itertools
from pmudef import *

import msr as msrmod
import latego
import event_download

force_download = False
pebs_enable = "p"

def has_format(s):
    return os.path.isfile("/sys/devices/cpu/format/" + s)

class PerfVersion:
    def __init__(self):
        minor = 0
        perf = os.getenv("PERF")
        if not perf:
            perf = "perf"
        try:
            version = subprocess.Popen([perf, "--version"], stdout=subprocess.PIPE).communicate()[0]
        except OSError:
            print "Cannot run", perf
            version = ""
        m = re.match(r"perf version (\d+)\.(\d+)\.", version)
        if m:
            major = m.group(1)
            minor = m.group(2)
            if re.match("[0-9]+", minor):
                minor = int(minor, 10)
            if re.match("[0-9]+", major) and int(major) > 3:
                minor = 100 # infinity

        self.direct = os.getenv("DIRECT_MSR") or minor < 4
        self.offcore = has_format("offcore_rsp") and not self.direct
        self.ldlat = has_format("ldlat") and not self.direct
        self.has_name = minor >= 4

version = PerfVersion()

class MSR:
    def __init__(self):
        self.reg = {}

    def writemsr(self, msrnum, val, print_only = False):
        print "msr %x = %x" % (msrnum, val, )
        if print_only:
            return
        msrmod.writemsr(msrnum, val)

    def checked_writemsr(self, msr, val, print_only = False):
        if msr in self.reg:
            sys.exit("Multiple events use same register")
        self.writemsr(msr, val, print_only)
        self.reg[msr] = 1

qual_map = (
    ("amt1", "any=1", EVENTSEL_ANY, ""),
    ("i1", "inv=1", EVENTSEL_INV, ""),
    ("tx", "in_tx=1", 0, ""),
    ("sup", "", 0, "k"),
    ("SUP", "", 0, "k"),
    ("usr=yes", "", 0, "u"),
    ("usr=no", "", 0, "k"),
    ("anythr=yes", "any=1", 0, ""),
    ("cp", "in_tx_cp=1", 0, ""))

qualval_map = (
    (r"c(mask=)?(0x[0-9a-f]+|[0-9]+)", "cmask=%d", 24),
    (r"(sa|sample-after)=([0-9]+)", "period=%d", 0))

# newe gets modified
def convert_extra(extra, val, newe):
    nextra = ""
    while extra:
        if extra[0] == ":":
            extra = extra[1:]
            continue
        found = False
        for j in qualval_map:
            m = re.match(j[0], extra)
            if m:
                if j[2]:
                    val |= int(m.group(2), 0) << j[2]
                newe.append(j[1] % (int(m.group(2), 0)))
                extra = extra[len(m.group(0)):]
                found = True
                break
        if found:
            continue
        found = False
        for j in qual_map:
            if extra.startswith(j[0]):
                val |= j[2]
                newe.append(j[1])
                extra = extra[len(j[0]):]
                nextra += j[3]
                found = True
                break
        if found:
            continue
        if not extra:
            break
        if extra[0] in perf_qual + "p":
            nextra += extra[0]
            extra = extra[1:]
            continue
        print >>sys.stderr, "bad event qualifier", extra
        break
    return nextra, val

class Event:
    def __init__(self, name, val, desc):
        self.val = val
        self.name = name
        self.extra = ""
        self.msr = 0
        self.msrval = 0
        self.desc = desc

    def output_newstyle(self, newextra="", noname=False, period=False, name=""):
        """Format an perf event for output and return as perf event string.
           Always uses new style (cpu/.../)."""
        val = self.val
        extra = self.newextra
        if newextra:
            extra += "," + newextra
        e = "event=0x%x,umask=0x%x%s" % (val & 0xff, (val >> 8) & 0xff, extra)
	if version.has_name:
	    if name:
		e += ",name=" + name
	    elif not noname:
		e += ",name=%s" % (self.name.replace(".", "_"),)
        if period and self.period:
            e += ",period=%d" % self.period
        return e

    def output(self, use_raw=False, flags="", noname=False, period=False, name=""):
        """Format an event for output and return as perf event string.
           use_raw when true return old style perf string (rXXX).
           Otherwise chose between old and new style based on the 
           capabilities of the installed perf executable.
           flags when set add perf flags (e.g. u for user, p for pebs)."""
        val = self.val
        newe = []
        extra = "".join(merge_extra(extra_set(self.extra), extra_set(flags)))
        extra, val = convert_extra(":" + extra, val, newe)
        if version.direct or use_raw:
            ename = "r%x" % (val,) 
            if extra:
                ename += ":" + extra
            # XXX should error for extras that don't fit into raw
        else:
	    ename = "cpu/%s/" % (self.output_newstyle(newextra=",".join(newe), noname=noname, period=period, name=name)) + extra
        return ename

box_to_perf = {
    "cbo": "cbox",
    "qpi_ll": "qpi",
    "sbo": "sbox",
}

box_cache = dict()

def box_exists(box):
    n = "/sys/devices/uncore_%s" % (box)
    if n not in box_cache:
        box_cache[n] = os.path.exists(n)
    return box_cache[n]

def int_or_zero(row, name):
    if name in row:
        if row[name] == 'False':
            return 0
        if row[name] == 'True':
            return 1
        return int(row[name])
    return 0

class UncoreEvent:
    def __init__(self, name, row):
        self.name = name
        e = self
        if 'PublicDescription' in row:
            e.desc = row['PublicDescription'].strip()
        elif 'BriefDescription' in row:
            e.desc = row['BriefDescription'].strip()
        else:
            e.desc = row['Description'].strip()
        e.code = int(row['EventCode'], 16)
        if 'Internal' in row and int(row['Internal']) != 0:
            e.code |= int(row['Internal']) << 21
        e.umask = int(row['UMask'], 16)
        e.cmask = int_or_zero(row, 'CounterMask')
        e.inv = int_or_zero(row, 'Invert')
        e.edge = int_or_zero(row, 'EdgeDetect')
        e.unit = row['Unit'].lower()
        if e.unit == "imph-u":
            e.unit = "arb"
        # xxx subctr
        if e.unit in box_to_perf:
            e.unit = box_to_perf[e.unit]
        e.msr = None
        e.overflow = 0
        e.counter = "1" # dummy for toplev
	if 'Errata' in row:
	    e.errata = row['Errata']
	else:
	    e.errata = None

    #  {
    # "Unit": "CBO",
    # "EventCode": "0x22",
    # "UMask": "0x21",
    # "EventName": "UNC_CBO_XSNP_RESPONSE.MISS_EXTERNAL",
    # "Description": "An external snoop misses in some processor core.",
    # "Counter": "0,1",
    # "CounterMask": "0",
    # "Invert": "0",
    # "EdgeDetect": "0"
    # },
    # XXX cannot separate sockets
    def output_newstyle(self, extra="", noname=False, period=False, name="", flags=""):
        # xxx multiply boxes
        # name ignored for now
        e = self
        o = "/event=%#x" % e.code
        if e.umask:
            o += ",umask=%#x" % e.umask
        if e.cmask:
            o += ",cmask=%#x" % e.cmask
        if e.edge:
            o += ",edge=1"
        if e.inv:
            o += ",inv=1"
        # xxx subctr, occ_sel, filters
        if flags:
            m = re.match(r'Match=(0x[0-9a-f])', flags)
            if m:
                o += ",filter_occ=" + m.group(1)
            else:
                print >>sys.stderr, "Uncore cannot parse %s", flags
        if version.has_name and not noname:
            o += ",name=" + e.name.replace(".", "_") + "_NUM"
        o += "/" + extra

        # explode boxes if needed
        def box_name(n):
            return "%s_%d" % (e.unit, n)
        def box_n_exists(n):
            return box_exists(box_name(n))
        if not box_exists(e.unit) and box_n_exists(0):
            return ",".join(["uncore_" + box_name(x) + o.replace("_NUM", "_%d" % (x)) for x in
                             itertools.takewhile(box_n_exists, itertools.count())])
        return "uncore_%s%s" % (e.unit, o.replace("_NUM", ""))

    output = output_newstyle

def ffs(flag):
    assert flag != 0
    m = 1
    j = 0
    while (flag & m) == 0:
        m = m << 1
        j += 1
    return j

perf_qual = "kuhGHSD" # without pebs

def extra_set(e):
    return set(map(lambda x: x[0],
        re.findall(r"(p+|" + "|".join([x[0] for x in qual_map + qualval_map]) + "|[" + perf_qual + "])", e)))

def merge_extra(a, b):
    m = a | b
    if 'ppp' in m:
        m = m - set(['p', 'pp'])
    if 'pp' in m:
        m = m - set(['p'])
    m = m - set([':'])
    return m

def print_event(name, desc, f, human, wrap):
    print >>f,"  %-42s" % (name,),
    if human:
        print >>f, "\n%s" % (wrap.fill(desc),)
    else:
        print >>f, " [%s]" % (desc,)

exists = set()
does_not_exist = set()

def cached_exists(fn):
    if fn in exists:
        return True
    if fn in does_not_exist:
        return False
    e = os.path.exists(fn)
    if e:
        exists.add(fn)
    else:
        does_not_exist.add(fn)
    return e

force_uncore = os.getenv("FORCE_UNCORE")

def uncore_exists(box, postfix=""):
    if force_uncore:
        return True
    if cached_exists("/sys/devices/uncore_" + box + postfix):
        return True
    if cached_exists("/sys/devices/uncore_" + box + "_0" + postfix):
        return True
    return False

missing_boxes = set()

def check_uncore_event(e):
    if uncore_exists(e.unit):
        if e.cmask and not uncore_exists(e.unit, "/format/cmask"):
            print >>sys.stderr, "Uncore unit", e.unit, "missing cmask for", e.name
            return None
        if e.umask and not uncore_exists(e.unit, "/format/umask"):
            print "Uncore unit", e.unit, "missing umask for", e.name
            return None
        return e
    if e.unit not in missing_boxes:
        print >>sys.stderr, "Uncore unit", e.unit, "missing"
        missing_boxes.add(e.unit)
    return None

fixed_counters = {
    "inst_retired.any": (0xc0, 0, 0),
    "cpu_clk_unhalted.thread": (0x3c, 0, 0),
    "cpu_clk_unhalted.thread_any": (0x3c, 0, 1),
}

class Emap(object):
    """Read an event table."""

    def __init__(self):
        self.events = {}
        self.codes = {}
        self.desc = {}
        self.pevents = {}
        self.latego = False
        self.uncore_events = {}

    def add_event(self, e):
        self.events[e.name] = e
        self.codes[e.val] = e
        self.desc[e.name] = e.desc

    def read_table(self, r, m):
        for row in r:
            get = lambda (x): row[m[x]]
            gethex = lambda (x): int(get(x).split(",")[0], 16)
            getdec = lambda (x): int(get(x), 10)

            name = get('name').lower().rstrip()
            code = gethex('code')
            umask = gethex('umask')
            anyf = 0
            if name in fixed_counters:
                code, umask, anyf = fixed_counters[name]
            if 'other' in m and m['other'] in row:
                other = gethex('other') << 16
            else:
                other = 0
            if 'edge' in m:
                other |= gethex('edge') << 18
            if 'any' in m:
                other |= (gethex('any') | anyf) << 21
            if 'cmask' in m:
                other |= getdec('cmask') << 24
            if 'invert' in m:
                other |= gethex('invert') << 23
            val = code | (umask << 8) | other
            val &= EVMASK
            d = get('desc').strip()
            try:
                d = d.encode('utf-8')
            except UnicodeDecodeError:
                pass
            e = Event(name, val, d)
            counter = get('counter')
            e.pname = "r%x" % (val,)
            e.newextra = ""
            if other & ((1<<16)|(1<<17)):
                if other & (1<<16):
                    e.extra += "u"
                if other & (1<<17):
                    e.extra += "k"
            if ('msr_index' in m and m['msr_index'] in row
                    and get('msr_index') and get('msr_value')):
                msrnum = gethex('msr_index')
                msrval = gethex('msr_value')
                if version.offcore and msrnum in (0x1a6, 0x1a7):
                    e.newextra = ",offcore_rsp=0x%x" % (msrval, )
                elif version.ldlat and msrnum in (0x3f6,):
                    e.newextra = ",ldlat=0x%x" % (msrval, )
                elif msrnum == 0x3f7:
                    e.newextra = ",frontend=%#x" % (msrval, )
                # add new msr here
                else:
                    e.msrval = msrval
                    e.msr = msrnum
            if 'overflow' in m and m['overflow'] in row:
                e.overflow = get('overflow')
                #if e.overflow == "0":
                #    print >>sys.stderr, "Warning: %s has no overflow value" % (name,)
            else:
                e.overflow = None
            e.pebs = get('pebs')
            if e.pebs and int(e.pebs):
                if name.endswith("_ps") or int(e.pebs) == 2:
                    e.extra += pebs_enable
                    d += " (Uses PEBS)"
                else:
                    d = d.replace("(Precise Event)","") + " (Supports PEBS)"
	    e.errata = None
            try:
                if get('errata') != "null":
                    d += " Errata: " + get('errata')
		    e.errata = get('errata')
            except KeyError:
                pass
            e.desc = d
            e.counter = get('counter')
            for (flag, name) in extra_flags:
                if val & flag:
                    e.newextra += ",%s=%d" % (name, (val & flag) >> ffs(flag), )
            e.period = int(get('sav')) if m['sav'] in row else 0
            self.add_event(e)

    def getevent(self, e):
        """Retrieve an event with name e. Return Event object or None."""
        e = e.lower()
        extra = ""
        edelim = ""
        m = re.match(r'(.*?):(.*)', e)
        if m:
            extra = m.group(2)
            edelim = ":"
            e = m.group(1)
        if e in self.events:
            extra = extra_set(extra)
            ev = self.events[e]
            ev_extra = extra_set(ev.extra)
            if extra and merge_extra(ev_extra, extra) > ev_extra:
                ev = copy.deepcopy(self.events[e])
                ev.extra = "".join(merge_extra(ev_extra, extra))
                return ev
            return self.events[e]
        elif e.endswith("_ps"):
            return self.getevent(e[:-3] + ":p" + extra)
        elif e.endswith("_0") or e.endswith("_1"):
            return self.getevent(e.replace("_0","").replace("_1","") + edelim + extra)
        elif e.startswith("offcore") and (e + "_0") in self.events:
            return self.getevent(e + "_0" + edelim + extra)
        elif e in self.uncore_events:
            return check_uncore_event(self.uncore_events[e])
        return None

    def update_event(self, e, ev):
        if e not in self.pevents:
            self.pevents[e] = ev
        
    def getraw(self, r):
        e = "r%x" % (r)
        if e in self.pevents:
            ev = self.pevents[e]
            s = ev.name
            if ev.extra:
                s += ":" + ev.extra
            return s
        return "!Raw 0x%x" % (r,)

    def getperf(self, p):
        if p in self.pevents:
            return self.pevents[p].name
        return p

    def dumpevents(self, f=sys.stdout, human=True):
        """Print all events with descriptions to the file descriptor f.
           When human is true word wrap all the descriptions."""
        wrap = None
        if human:
            wrap = textwrap.TextWrapper(initial_indent="     ",
                                        subsequent_indent="     ")            
        for k in sorted(self.events.keys()):
            print_event(k, self.desc[k], f, human, wrap)
        for k in sorted(self.uncore_events.keys()):
            print_event(k, self.uncore_events[k].desc, f, human, wrap)

class EmapNativeJSON(Emap):
    def __init__(self, name):
        mapping = {
            'name': u'EventName',
            'code': u'EventCode',
            'umask': u'UMask',
            'msr_index': u'MSRIndex',
            'msr_value': u'MSRValue',
            'cmask': u'CounterMask',
            'invert': u'Invert',
            'any': u'AnyThread',
            'edge': u'EdgeDetect',
            'desc': u'PublicDescription',
            'pebs': u'PEBS',
            'counter': u'Counter',
            'overflow': u'SampleAfterValue',
            'errata': u'Errata',
            'sav': u'SampleAfterValue',
            'other': u'Other',
        }
        super(EmapNativeJSON, self).__init__()
        if name.find("JKT") >= 0:
            self.latego = True
        try:
            data = json.load(open(name, 'rb'))
        except ValueError as e:
            print >>sys.stderr, "Cannot open", name + ":", e.message
            return
        if u'PublicDescription' not in data[0]:
            mapping['desc'] = u'BriefDescription'
        self.read_table(data, mapping)

    def add_offcore(self, name):
        data = json.load(open(name, 'rb'))
        #   {
        #    "MATRIX_REQUEST": "DEMAND_DATA_RD",
        #    "MATRIX_RESPONSE": "NULL",
        #    "MATRIX_VALUE": "0x0000000001",
        #    "MATRIX_REGISTER": "0,1",
        #    "DESCRIPTION": "Counts demand data reads that"
        #   },

        offcore_response = self.getevent("OFFCORE_RESPONSE")
        if not offcore_response:
            return
        requests = []
        responses = []

        for row in data:
            if row[u"MATRIX_REQUEST"].upper() != "NULL":
                requests.append((row[u"MATRIX_REQUEST"], row[u"MATRIX_VALUE"], row[u"DESCRIPTION"]))
            if row[u"MATRIX_RESPONSE"].upper() != "NULL":
                responses.append((row[u"MATRIX_RESPONSE"], row[u"MATRIX_VALUE"], row[u"DESCRIPTION"]))

        def create_event(req_name, req_val, req_desc, res_name, res_val, res_desc):
            oe = copy.deepcopy(offcore_response)
            oe.name = ("OFFCORE_RESPONSE.%s.%s" % (req_name, res_name)).lower()
            oe.msrval = int(req_val, 16) | int(res_val, 16)
            oe.desc = req_desc + " " + res_desc
            if version.offcore:
                oe.newextra = ",offcore_rsp=0x%x" % (oe.msrval, )
            else:
                oe.msr = 0x1a6
            self.add_event(oe)

        for a, b in itertools.product(requests, responses):
            create_event(*(a + b))

    def add_uncore(self, name):
        if len(self.uncore_events) > 0:
            return
        data = json.load(open(name, "rb"))
        for row in data:
            name = row['EventName'].lower()
            try:
                self.uncore_events[name] = UncoreEvent(name, row)
            except UnicodeEncodeError:
                pass

def json_with_extra(el):
    emap = EmapNativeJSON(event_download.eventlist_name(el, "core"))
    if not emap:
        return None
    add_extra_env(emap, el)
    return emap

def add_extra_env(emap, el):
    oc = os.getenv("OFFCORE")
    if oc:
        emap.add_offcore(oc)
    else:
        oc = event_download.eventlist_name(el, "offcore")
        if os.path.exists(oc):
            emap.add_offcore(oc)
    uc = os.getenv("UNCORE")
    if uc:
        emap.add_uncore(uc)
    else:
        uc = event_download.eventlist_name(el, "uncore")
        if os.path.exists(uc):
            emap.add_uncore(uc)
    return emap

def find_emap():
    """Search and read a perfmon event map.
       When the EVENTMAP environment variable is set read that, otherwise
       read the map for the current CPU. EVENTMAP can be a CPU specifier 
       in the map file or a path name.
       Dito for the OFFCORE and UNCORE environment variables.

       Return an emap object that contains the events and can be queried
       or None if nothing is found or the current CPU is unknown."""
    el = os.getenv("EVENTMAP")
    if not el:
        el = event_download.get_cpustr()
    if el.find("/") >= 0:
        try:
            emap = EmapNativeJSON(el)
            if emap:
                add_extra_env(emap, el)
            return emap
        except IOError:
            return None
    try:
        if not force_download:
            emap = json_with_extra(el)
            if emap:
                return emap
    except IOError:
        pass
    try:
        toget = ["core"]
        if not os.getenv("OFFCORE"):
            toget.append("offcore")
        if not os.getenv("UNCORE"):
            toget.append("uncore")
        if not os.getenv("UNCORE"):
            toget.append("uncore")
        event_download.download(el, toget)
        return json_with_extra(el)
    except IOError:
        pass
    return None

def process_events(event, print_only, period):
    overflow = None
    # replace inner commas so we can split events
    event = re.sub(r"([a-z][a-z0-9]+/)([^/]+)/",
            lambda m: m.group(1) + m.group(2).replace(",", "#") + "/",
            event)
    el = event.split(",")
    nl = []
    for i in el:
        start = ""
        end = ""
        if i.startswith('{'):
            start = "{"
            i = i[1:]
        if i.endswith('}'):
            end = "}"
            i = i[:-1]
        i = i.strip()
        m = re.match(r"(cpu/)([a-zA-Z0-9._]+)(.*?/)([^,]*)", i)
        if not m:
            m = re.match(r"(uncore_.+?/)([a-zA-Z0-9_.]+)(.*?/)([^,]*)", i)
        if m:
            start += m.group(1)
            ev = emap.getevent(m.group(2))
            end += m.group(3)
            if ev:
                end += "".join(merge_extra(extra_set(ev.extra), extra_set(m.group(4))))
                i = ev.output_newstyle(period=period)
            else:
                start = ""
                end = ""
        else:
            extra = ""
            m = re.match("([^:]*):(.*)", i)
            if m:
                extra = m.group(2)
                i = m.group(1)
            ev = emap.getevent(i)
            if ev:
                i = ev.output(flags=extra, period=period)
            else:
               if extra:
                   i += ":" + extra
        if ev:
            if ev.msr:
                msr.checked_writemsr(ev.msr, ev.msrval, print_only)
            if emap.latego and (ev.val & 0xffff) in latego.latego_events:
                latego.setup_event(ev.val & 0xffff, 1)
            overflow = ev.overflow
        event = (start + i + end).replace("#", ",")
        nl.append(event)
        if ev:
            emap.update_event(event, ev)

    return str.join(',', nl), overflow

def getarg(i, cmd):
    if sys.argv[i][2:] == '':
        cmd.append(sys.argv[i])
        i += 1
        arg = ""
        if len(sys.argv) > i:
            arg = sys.argv[i]
        prefix = ""
    else:
        arg = sys.argv[i][2:]
        prefix = sys.argv[i][:2]
    return arg, i, prefix

def process_args():
    perf = os.getenv("PERF")
    if not perf:
        perf = "perf"
    cmd = [perf]

    overflow = None
    print_only = False
    never, no, yes = range(3)
    record = no
    i = 1
    while i < len(sys.argv):
        if sys.argv[i] == "--print":
            print_only = True
        elif sys.argv[i] == "--force-download":
           pass
        elif sys.argv[i] == "--no-period":
            record = never
        # XXX does not handle options between perf and record
        elif sys.argv[i] == "record" and record == no:
            cmd.append(sys.argv[i])
            record = yes
        elif sys.argv[i][0:2] == '-e':
            event, i, prefix = getarg(i, cmd)
            event, overflow = process_events(event, print_only,
                                             True if record == yes else False)
            cmd.append(prefix + event)
        elif sys.argv[i][0:2] == '-c':
            oarg, i, prefix = getarg(i, cmd)
            if oarg == "default":
                if overflow is None:
                    print >>sys.stderr,"""
Specify the -e events before -c default or event has no overflow field."""
                    sys.exit(1)
                cmd.append(prefix + overflow)
            else:
                cmd.append(prefix + oarg)
        else:        
            cmd.append(sys.argv[i])
        i += 1
    print " ".join(map(pipes.quote, cmd))
    if print_only:
        sys.exit(0)
    return cmd

def get_pager():
    f = sys.stdout
    if f.isatty():
        try:
            sp = subprocess.Popen(["less", "-F"], stdin=subprocess.PIPE)
            return sp.stdin, sp
        except OSError:
            f = sys.stdout
    return f, None

def perf_cmd(cmd):
    if len(sys.argv) >= 2 and sys.argv[1] == "list":
        pager, proc = get_pager()
        try:
            l = subprocess.Popen(cmd, stdout=pager)
            l.wait()
            print >>pager
            emap.dumpevents(pager, proc is not None)
            if proc:
                pager.close()
                proc.wait()
        except IOError:
            pass
    elif len(sys.argv) >= 2 and (sys.argv[1] == "report" or sys.argv[1] == "stat"):
        direct = version.has_name
        if not direct:
            for w in sys.argv:
                if w == "--tui":
                    direct = True
                    break
        if direct:
            ret = subprocess.call(cmd)
            latego.cleanup()
            sys.exit(ret)
        try:
            pipe = subprocess.Popen(cmd,
                                    stdout=subprocess.PIPE,
                                    stderr=subprocess.STDOUT).stdout
            raw = lambda e: " " + emap.getraw(int(e.group(1), 16))
            for i in pipe:
                i = re.sub("[rR]aw 0x([0-9a-f]{4,})", raw, i)
                i = re.sub("r([0-9a-f]{4,})", raw, i)
                i = re.sub("(cpu/.*?/)", lambda e: emap.getperf(e.group(1)), i)
                print i,
        except IOError:
            pass
        pipe.close()
        latego.cleanup()
    else:
        sys.exit(subprocess.call(cmd))

if __name__ == '__main__':
    for j in sys.argv:
        if j == "--force-download":
            force_download = True
    emap = find_emap()
    if not emap:
        sys.exit("Do not recognize CPU or cannot find CPU map file")
    msr = MSR()
    cmd = process_args()
    try:
        perf_cmd(cmd)
    except KeyboardInterrupt:
        pass