Merge tag 'perf-tools-for-v6.10-1-2024-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Arnaldo Carvalho de Melo:
 "General:

   - Integrate the shellcheck utility with the build of perf to allow
     catching shell problems early in areas such as 'perf test', 'perf
     trace' scrape scripts, etc

   - Add 'uretprobe' variant in the 'perf bench uprobe' tool

   - Add script to run instances of 'perf script' in parallel

   - Allow parsing tracepoint names that start with digits, such as
     9p/9p_client_req, etc. Make sure 'perf test' tests it even on
     systems where those tracepoints aren't available

   - Add Kan Liang to MAINTAINERS as a perf tools reviewer

   - Add support for using the 'capstone' disassembler library in
     various tools, such as 'perf script' and 'perf annotate'. This is
     an alternative for the use of the 'xed' and 'objdump' disassemblers

  Data-type profiling improvements:

   - Resolve types for a->b->c by backtracking the assignments until it
     finds DWARF info for one of those members

   - Support for global variables, keeping a cache to speed up lookups

   - Handle the 'call' instruction, dealing with effects on registers
     and handling its return when tracking register data types

   - Handle x86's segment based addressing like %gs:0x28, to support
     things like per CPU variables, the stack canary, etc

   - Data-type profiling got big speedups when using capstone for
     disassembling. The objdump outoput parsing method is left as a
     fallback when capstone fails or isn't available. There are patches
     posted for 6.11 that to use a LLVM disassembler

   - Support event group display in the TUI when annotating types with
     --data-type, for instance to show memory load and store events for
     the data type fields

   - Optimize the 'perf annotate' data structures, reducing memory usage

   - Add a initial 'perf test' for 'perf annotate', checking that a
     target symbol appears on the output, specifying objdump via the
     command line, etc

  Vendor Events:

   - Update Intel JSON files for Cascade Lake X, Emerald Rapids, Grand
     Ridge, Ice Lake X, Lunar Lake, Meteor Lake, Sapphire Rapids, Sierra
     Forest, Sky Lake X, Sky Lake and Snow Ridge X. Remove info metrics
     erroneously in TopdownL1

   - Add AMD's Zen 5 core and uncore events and metrics. Those come from
     the "Performance Monitor Counters for AMD Family 1Ah Model 00h- 0Fh
     Processors" document, with events that capture information on op
     dispatch, execution and retirement, branch prediction, L1 and L2
     cache activity, TLB activity, etc

   - Mark L1D_CACHE_INVAL impacted by errata for ARM64's AmpereOne/
     AmpereOneX

  Miscellaneous:

   - Sync header copies with the kernel sources

   - Move some header copies used only for generating translation string
     tables for ioctl cmds and other syscall integer arguments to a new
     directory under tools/perf/beauty/, to separate from copies in
     tools/include/ that are used to build the tools

   - Introduce scrape script for several syscall 'flags'/'mask'
     arguments

   - Improve cpumap utilization, fixing up pairing of refcounts, using
     the right iterators (perf_cpu_map__for_each_cpu), etc

   - Give more details about raw event encodings in 'perf list', show
     tracepoint encoding in the detailed output

   - Refactor the DSOs handling code, reducing memory usage

   - Document the BPF event modifier and add a 'perf test' for it

   - Improve the event parser, better error messages and add further
     'perf test's for it

   - Add reference count checking to 'struct comm_str' and 'struct
     mem_info'

   - Make ARM64's 'perf test' entries for the Neoverse N1 more robust

   - Tweak the ARM64's Coresight 'perf test's

   - Improve ARM64's CoreSight ETM version detection and error reporting

   - Fix handling of symbols when using kcore

   - Fix PAI (Processor Activity Instrumentation) counter names for s390
     virtual machines in 'perf report'

   - Fix -g/--call-graph option failure in 'perf sched timehist'

   - Add LIBTRACEEVENT_DIR build option to allow building with
     libtraceevent installed in non-standard directories, such as when
     doing cross builds

   - Various 'perf test' and 'perf bench' fixes

   - Improve 'perf probe' error message for long C++ probe names"

* tag 'perf-tools-for-v6.10-1-2024-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (260 commits)
  tools lib subcmd: Show parent options in help
  perf pmu: Count sys and cpuid JSON events separately
  perf stat: Don't display metric header for non-leader uncore events
  perf annotate-data: Ensure the number of type histograms
  perf annotate: Fix segfault on sample histogram
  perf daemon: Fix file leak in daemon_session__control
  libsubcmd: Fix parse-options memory leak
  perf lock: Avoid memory leaks from strdup()
  perf sched: Rename 'switches' column header to 'count' and add usage description, options for latency
  perf tools: Ignore deleted cgroups
  perf parse: Allow tracepoint names to start with digits
  perf parse-events: Add new 'fake_tp' parameter for tests
  perf parse-events: pass parse_state to add_tracepoint
  perf symbols: Fix ownership of string in dso__load_vmlinux()
  perf symbols: Update kcore map before merging in remaining symbols
  perf maps: Re-use __maps__free_maps_by_name()
  perf symbols: Remove map from list before updating addresses
  perf tracepoint: Don't scan all tracepoints to test if one exists
  perf dwarf-aux: Fix build with HAVE_DWARF_CFI_SUPPORT
  perf thread: Fixes to thread__new() related to initializing comm
  ...

1 files changed, 988 insertions, 0 deletions

diff --git a/tools/perf/scripts/python/parallel-perf.py b/tools/perf/scripts/python/parallel-perf.py
new file mode 100755
index 000000000000..21f32ec5ed46
--- /dev/null
+++ b/tools/perf/scripts/python/parallel-perf.py
@@ -0,0 +1,988 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+#
+# Run a perf script command multiple times in parallel, using perf script
+# options --cpu and --time so that each job processes a different chunk
+# of the data.
+#
+# Copyright (c) 2024, Intel Corporation.
+
+import subprocess
+import argparse
+import pathlib
+import shlex
+import time
+import copy
+import sys
+import os
+import re
+
+glb_prog_name = "parallel-perf.py"
+glb_min_interval = 10.0
+glb_min_samples = 64
+
+class Verbosity():
+
+	def __init__(self, quiet=False, verbose=False, debug=False):
+		self.normal    = True
+		self.verbose   = verbose
+		self.debug     = debug
+		self.self_test = True
+		if self.debug:
+			self.verbose = True
+		if self.verbose:
+			quiet = False
+		if quiet:
+			self.normal = False
+
+# Manage work (Start/Wait/Kill), as represented by a subprocess.Popen command
+class Work():
+
+	def __init__(self, cmd, pipe_to, output_dir="."):
+		self.popen = None
+		self.consumer = None
+		self.cmd = cmd
+		self.pipe_to = pipe_to
+		self.output_dir = output_dir
+		self.cmdout_name = f"{output_dir}/cmd.txt"
+		self.stdout_name = f"{output_dir}/out.txt"
+		self.stderr_name = f"{output_dir}/err.txt"
+
+	def Command(self):
+		sh_cmd = [ shlex.quote(x) for x in self.cmd ]
+		return " ".join(self.cmd)
+
+	def Stdout(self):
+		return open(self.stdout_name, "w")
+
+	def Stderr(self):
+		return open(self.stderr_name, "w")
+
+	def CreateOutputDir(self):
+		pathlib.Path(self.output_dir).mkdir(parents=True, exist_ok=True)
+
+	def Start(self):
+		if self.popen:
+			return
+		self.CreateOutputDir()
+		with open(self.cmdout_name, "w") as f:
+			f.write(self.Command())
+			f.write("\n")
+		stdout = self.Stdout()
+		stderr = self.Stderr()
+		if self.pipe_to:
+			self.popen = subprocess.Popen(self.cmd, stdout=subprocess.PIPE, stderr=stderr)
+			args = shlex.split(self.pipe_to)
+			self.consumer = subprocess.Popen(args, stdin=self.popen.stdout, stdout=stdout, stderr=stderr)
+		else:
+			self.popen = subprocess.Popen(self.cmd, stdout=stdout, stderr=stderr)
+
+	def RemoveEmptyErrFile(self):
+		if os.path.exists(self.stderr_name):
+			if os.path.getsize(self.stderr_name) == 0:
+				os.unlink(self.stderr_name)
+
+	def Errors(self):
+		if os.path.exists(self.stderr_name):
+			if os.path.getsize(self.stderr_name) != 0:
+				return [ f"Non-empty error file {self.stderr_name}" ]
+		return []
+
+	def TidyUp(self):
+		self.RemoveEmptyErrFile()
+
+	def RawPollWait(self, p, wait):
+		if wait:
+			return p.wait()
+		return p.poll()
+
+	def Poll(self, wait=False):
+		if not self.popen:
+			return None
+		result = self.RawPollWait(self.popen, wait)
+		if self.consumer:
+			res = result
+			result = self.RawPollWait(self.consumer, wait)
+			if result != None and res == None:
+				self.popen.kill()
+				result = None
+			elif result == 0 and res != None and res != 0:
+				result = res
+		if result != None:
+			self.TidyUp()
+		return result
+
+	def Wait(self):
+		return self.Poll(wait=True)
+
+	def Kill(self):
+		if not self.popen:
+			return
+		self.popen.kill()
+		if self.consumer:
+			self.consumer.kill()
+
+def KillWork(worklist, verbosity):
+	for w in worklist:
+		w.Kill()
+	for w in worklist:
+		w.Wait()
+
+def NumberOfCPUs():
+	return os.sysconf("SC_NPROCESSORS_ONLN")
+
+def NanoSecsToSecsStr(x):
+	if x == None:
+		return ""
+	x = str(x)
+	if len(x) < 10:
+		x = "0" * (10 - len(x)) + x
+	return x[:len(x) - 9] + "." + x[-9:]
+
+def InsertOptionAfter(cmd, option, after):
+	try:
+		pos = cmd.index(after)
+		cmd.insert(pos + 1, option)
+	except:
+		cmd.append(option)
+
+def CreateWorkList(cmd, pipe_to, output_dir, cpus, time_ranges_by_cpu):
+	max_len = len(str(cpus[-1]))
+	cpu_dir_fmt = f"cpu-%.{max_len}u"
+	worklist = []
+	pos = 0
+	for cpu in cpus:
+		if cpu >= 0:
+			cpu_dir = os.path.join(output_dir, cpu_dir_fmt % cpu)
+			cpu_option = f"--cpu={cpu}"
+		else:
+			cpu_dir = output_dir
+			cpu_option = None
+
+		tr_dir_fmt = "time-range"
+
+		if len(time_ranges_by_cpu) > 1:
+			time_ranges = time_ranges_by_cpu[pos]
+			tr_dir_fmt += f"-{pos}"
+			pos += 1
+		else:
+			time_ranges = time_ranges_by_cpu[0]
+
+		max_len = len(str(len(time_ranges)))
+		tr_dir_fmt += f"-%.{max_len}u"
+
+		i = 0
+		for r in time_ranges:
+			if r == [None, None]:
+				time_option = None
+				work_output_dir = cpu_dir
+			else:
+				time_option = "--time=" + NanoSecsToSecsStr(r[0]) + "," + NanoSecsToSecsStr(r[1])
+				work_output_dir = os.path.join(cpu_dir, tr_dir_fmt % i)
+				i += 1
+			work_cmd = list(cmd)
+			if time_option != None:
+				InsertOptionAfter(work_cmd, time_option, "script")
+			if cpu_option != None:
+				InsertOptionAfter(work_cmd, cpu_option, "script")
+			w = Work(work_cmd, pipe_to, work_output_dir)
+			worklist.append(w)
+	return worklist
+
+def DoRunWork(worklist, nr_jobs, verbosity):
+	nr_to_do = len(worklist)
+	not_started = list(worklist)
+	running = []
+	done = []
+	chg = False
+	while True:
+		nr_done = len(done)
+		if chg and verbosity.normal:
+			nr_run = len(running)
+			print(f"\rThere are {nr_to_do} jobs: {nr_done} completed, {nr_run} running", flush=True, end=" ")
+			if verbosity.verbose:
+				print()
+			chg = False
+		if nr_done == nr_to_do:
+			break
+		while len(running) < nr_jobs and len(not_started):
+			w = not_started.pop(0)
+			running.append(w)
+			if verbosity.verbose:
+				print("Starting:", w.Command())
+			w.Start()
+			chg = True
+		if len(running):
+			time.sleep(0.1)
+		finished = []
+		not_finished = []
+		while len(running):
+			w = running.pop(0)
+			r = w.Poll()
+			if r == None:
+				not_finished.append(w)
+				continue
+			if r == 0:
+				if verbosity.verbose:
+					print("Finished:", w.Command())
+				finished.append(w)
+				chg = True
+				continue
+			if verbosity.normal and not verbosity.verbose:
+				print()
+			print("Job failed!\n    return code:", r, "\n    command:    ", w.Command())
+			if w.pipe_to:
+				print("    piped to:   ", w.pipe_to)
+			print("Killing outstanding jobs")
+			KillWork(not_finished, verbosity)
+			KillWork(running, verbosity)
+			return False
+		running = not_finished
+		done += finished
+	errorlist = []
+	for w in worklist:
+		errorlist += w.Errors()
+	if len(errorlist):
+		print("Errors:")
+		for e in errorlist:
+			print(e)
+	elif verbosity.normal:
+		print("\r"," "*50, "\rAll jobs finished successfully", flush=True)
+	return True
+
+def RunWork(worklist, nr_jobs=NumberOfCPUs(), verbosity=Verbosity()):
+	try:
+		return DoRunWork(worklist, nr_jobs, verbosity)
+	except:
+		for w in worklist:
+			w.Kill()
+		raise
+	return True
+
+def ReadHeader(perf, file_name):
+	return subprocess.Popen([perf, "script", "--header-only", "--input", file_name], stdout=subprocess.PIPE).stdout.read().decode("utf-8")
+
+def ParseHeader(hdr):
+	result = {}
+	lines = hdr.split("\n")
+	for line in lines:
+		if ":" in line and line[0] == "#":
+			pos = line.index(":")
+			name = line[1:pos-1].strip()
+			value = line[pos+1:].strip()
+			if name in result:
+				orig_name = name
+				nr = 2
+				while True:
+					name = f"{orig_name} {nr}"
+					if name not in result:
+						break
+					nr += 1
+			result[name] = value
+	return result
+
+def HeaderField(hdr_dict, hdr_fld):
+	if hdr_fld not in hdr_dict:
+		raise Exception(f"'{hdr_fld}' missing from header information")
+	return hdr_dict[hdr_fld]
+
+# Represent the position of an option within a command string
+# and provide the option value and/or remove the option
+class OptPos():
+
+	def Init(self, opt_element=-1, value_element=-1, opt_pos=-1, value_pos=-1, error=None):
+		self.opt_element = opt_element		# list element that contains option
+		self.value_element = value_element	# list element that contains option value
+		self.opt_pos = opt_pos			# string position of option
+		self.value_pos = value_pos		# string position of value
+		self.error = error			# error message string
+
+	def __init__(self, args, short_name, long_name, default=None):
+		self.args = list(args)
+		self.default = default
+		n = 2 + len(long_name)
+		m = len(short_name)
+		pos = -1
+		for opt in args:
+			pos += 1
+			if m and opt[:2] == f"-{short_name}":
+				if len(opt) == 2:
+					if pos + 1 < len(args):
+						self.Init(pos, pos + 1, 0, 0)
+					else:
+						self.Init(error = f"-{short_name} option missing value")
+				else:
+					self.Init(pos, pos, 0, 2)
+				return
+			if opt[:n] == f"--{long_name}":
+				if len(opt) == n:
+					if pos + 1 < len(args):
+						self.Init(pos, pos + 1, 0, 0)
+					else:
+						self.Init(error = f"--{long_name} option missing value")
+				elif opt[n] == "=":
+					self.Init(pos, pos, 0, n + 1)
+				else:
+					self.Init(error = f"--{long_name} option expected '='")
+				return
+			if m and opt[:1] == "-" and opt[:2] != "--" and short_name in opt:
+				ipos = opt.index(short_name)
+				if "-" in opt[1:]:
+					hpos = opt[1:].index("-")
+					if hpos < ipos:
+						continue
+				if ipos + 1 == len(opt):
+					if pos + 1 < len(args):
+						self.Init(pos, pos + 1, ipos, 0)
+					else:
+						self.Init(error = f"-{short_name} option missing value")
+				else:
+					self.Init(pos, pos, ipos, ipos + 1)
+				return
+		self.Init()
+
+	def Value(self):
+		if self.opt_element >= 0:
+			if self.opt_element != self.value_element:
+				return self.args[self.value_element]
+			else:
+				return self.args[self.value_element][self.value_pos:]
+		return self.default
+
+	def Remove(self, args):
+		if self.opt_element == -1:
+			return
+		if self.opt_element != self.value_element:
+			del args[self.value_element]
+		if self.opt_pos:
+			args[self.opt_element] = args[self.opt_element][:self.opt_pos]
+		else:
+			del args[self.opt_element]
+
+def DetermineInputFileName(cmd):
+	p = OptPos(cmd, "i", "input", "perf.data")
+	if p.error:
+		raise Exception(f"perf command {p.error}")
+	file_name = p.Value()
+	if not os.path.exists(file_name):
+		raise Exception(f"perf command input file '{file_name}' not found")
+	return file_name
+
+def ReadOption(args, short_name, long_name, err_prefix, remove=False):
+	p = OptPos(args, short_name, long_name)
+	if p.error:
+		raise Exception(f"{err_prefix}{p.error}")
+	value = p.Value()
+	if remove:
+		p.Remove(args)
+	return value
+
+def ExtractOption(args, short_name, long_name, err_prefix):
+	return ReadOption(args, short_name, long_name, err_prefix, True)
+
+def ReadPerfOption(args, short_name, long_name):
+	return ReadOption(args, short_name, long_name, "perf command ")
+
+def ExtractPerfOption(args, short_name, long_name):
+	return ExtractOption(args, short_name, long_name, "perf command ")
+
+def PerfDoubleQuickCommands(cmd, file_name):
+	cpu_str = ReadPerfOption(cmd, "C", "cpu")
+	time_str = ReadPerfOption(cmd, "", "time")
+	# Use double-quick sampling to determine trace data density
+	times_cmd = ["perf", "script", "--ns", "--input", file_name, "--itrace=qqi"]
+	if cpu_str != None and cpu_str != "":
+		times_cmd.append(f"--cpu={cpu_str}")
+	if time_str != None and time_str != "":
+		times_cmd.append(f"--time={time_str}")
+	cnts_cmd = list(times_cmd)
+	cnts_cmd.append("-Fcpu")
+	times_cmd.append("-Fcpu,time")
+	return cnts_cmd, times_cmd
+
+class CPUTimeRange():
+	def __init__(self, cpu):
+		self.cpu = cpu
+		self.sample_cnt = 0
+		self.time_ranges = None
+		self.interval = 0
+		self.interval_remaining = 0
+		self.remaining = 0
+		self.tr_pos = 0
+
+def CalcTimeRangesByCPU(line, cpu, cpu_time_ranges, max_time):
+	cpu_time_range = cpu_time_ranges[cpu]
+	cpu_time_range.remaining -= 1
+	cpu_time_range.interval_remaining -= 1
+	if cpu_time_range.remaining == 0:
+		cpu_time_range.time_ranges[cpu_time_range.tr_pos][1] = max_time
+		return
+	if cpu_time_range.interval_remaining == 0:
+		time = TimeVal(line[1][:-1], 0)
+		time_ranges = cpu_time_range.time_ranges
+		time_ranges[cpu_time_range.tr_pos][1] = time - 1
+		time_ranges.append([time, max_time])
+		cpu_time_range.tr_pos += 1
+		cpu_time_range.interval_remaining = cpu_time_range.interval
+
+def CountSamplesByCPU(line, cpu, cpu_time_ranges):
+	try:
+		cpu_time_ranges[cpu].sample_cnt += 1
+	except:
+		print("exception")
+		print("cpu", cpu)
+		print("len(cpu_time_ranges)", len(cpu_time_ranges))
+		raise
+
+def ProcessCommandOutputLines(cmd, per_cpu, fn, *x):
+	# Assume CPU number is at beginning of line and enclosed by []
+	pat = re.compile(r"\s*\[[0-9]+\]")
+	p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+	while True:
+		if line := p.stdout.readline():
+			line = line.decode("utf-8")
+			if pat.match(line):
+				line = line.split()
+				if per_cpu:
+					# Assumes CPU number is enclosed by []
+					cpu = int(line[0][1:-1])
+				else:
+					cpu = 0
+				fn(line, cpu, *x)
+		else:
+			break
+	p.wait()
+
+def IntersectTimeRanges(new_time_ranges, time_ranges):
+	pos = 0
+	new_pos = 0
+	# Can assume len(time_ranges) != 0 and len(new_time_ranges) != 0
+	# Note also, there *must* be at least one intersection.
+	while pos < len(time_ranges) and new_pos < len(new_time_ranges):
+		# new end < old start => no intersection, remove new
+		if new_time_ranges[new_pos][1] < time_ranges[pos][0]:
+			del new_time_ranges[new_pos]
+			continue
+		# new start > old end => no intersection, check next
+		if new_time_ranges[new_pos][0] > time_ranges[pos][1]:
+			pos += 1
+			if pos < len(time_ranges):
+				continue
+			# no next, so remove remaining
+			while new_pos < len(new_time_ranges):
+				del new_time_ranges[new_pos]
+			return
+		# Found an intersection
+		# new start < old start => adjust new start = old start
+		if new_time_ranges[new_pos][0] < time_ranges[pos][0]:
+			new_time_ranges[new_pos][0] = time_ranges[pos][0]
+		# new end > old end => keep the overlap, insert the remainder
+		if new_time_ranges[new_pos][1] > time_ranges[pos][1]:
+			r = [ time_ranges[pos][1] + 1, new_time_ranges[new_pos][1] ]
+			new_time_ranges[new_pos][1] = time_ranges[pos][1]
+			new_pos += 1
+			new_time_ranges.insert(new_pos, r)
+			continue
+		# new [start, end] is within old [start, end]
+		new_pos += 1
+
+def SplitTimeRangesByTraceDataDensity(time_ranges, cpus, nr, cmd, file_name, per_cpu, min_size, min_interval, verbosity):
+	if verbosity.normal:
+		print("\rAnalyzing...", flush=True, end=" ")
+		if verbosity.verbose:
+			print()
+	cnts_cmd, times_cmd = PerfDoubleQuickCommands(cmd, file_name)
+
+	nr_cpus = cpus[-1] + 1 if per_cpu else 1
+	if per_cpu:
+		nr_cpus = cpus[-1] + 1
+		cpu_time_ranges = [ CPUTimeRange(cpu) for cpu in range(nr_cpus) ]
+	else:
+		nr_cpus = 1
+		cpu_time_ranges = [ CPUTimeRange(-1) ]
+
+	if verbosity.debug:
+		print("nr_cpus", nr_cpus)
+		print("cnts_cmd", cnts_cmd)
+		print("times_cmd", times_cmd)
+
+	# Count the number of "double quick" samples per CPU
+	ProcessCommandOutputLines(cnts_cmd, per_cpu, CountSamplesByCPU, cpu_time_ranges)
+
+	tot = 0
+	mx = 0
+	for cpu_time_range in cpu_time_ranges:
+		cnt = cpu_time_range.sample_cnt
+		tot += cnt
+		if cnt > mx:
+			mx = cnt
+		if verbosity.debug:
+			print("cpu:", cpu_time_range.cpu, "sample_cnt", cnt)
+
+	if min_size < 1:
+		min_size = 1
+
+	if mx < min_size:
+		# Too little data to be worth splitting
+		if verbosity.debug:
+			print("Too little data to split by time")
+		if nr == 0:
+			nr = 1
+		return [ SplitTimeRangesIntoN(time_ranges, nr, min_interval) ]
+
+	if nr:
+		divisor = nr
+		min_size = 1
+	else:
+		divisor = NumberOfCPUs()
+
+	interval = int(round(tot / divisor, 0))
+	if interval < min_size:
+		interval = min_size
+
+	if verbosity.debug:
+		print("divisor", divisor)
+		print("min_size", min_size)
+		print("interval", interval)
+
+	min_time = time_ranges[0][0]
+	max_time = time_ranges[-1][1]
+
+	for cpu_time_range in cpu_time_ranges:
+		cnt = cpu_time_range.sample_cnt
+		if cnt == 0:
+			cpu_time_range.time_ranges = copy.deepcopy(time_ranges)
+			continue
+		# Adjust target interval for CPU to give approximately equal interval sizes
+		# Determine number of intervals, rounding to nearest integer
+		n = int(round(cnt / interval, 0))
+		if n < 1:
+			n = 1
+		# Determine interval size, rounding up
+		d, m = divmod(cnt, n)
+		if m:
+			d += 1
+		cpu_time_range.interval = d
+		cpu_time_range.interval_remaining = d
+		cpu_time_range.remaining = cnt
+		# Init. time ranges for each CPU with the start time
+		cpu_time_range.time_ranges = [ [min_time, max_time] ]
+
+	# Set time ranges so that the same number of "double quick" samples
+	# will fall into each time range.
+	ProcessCommandOutputLines(times_cmd, per_cpu, CalcTimeRangesByCPU, cpu_time_ranges, max_time)
+
+	for cpu_time_range in cpu_time_ranges:
+		if cpu_time_range.sample_cnt:
+			IntersectTimeRanges(cpu_time_range.time_ranges, time_ranges)
+
+	return [cpu_time_ranges[cpu].time_ranges for cpu in cpus]
+
+def SplitSingleTimeRangeIntoN(time_range, n):
+	if n <= 1:
+		return [time_range]
+	start = time_range[0]
+	end   = time_range[1]
+	duration = int((end - start + 1) / n)
+	if duration < 1:
+		return [time_range]
+	time_ranges = []
+	for i in range(n):
+		time_ranges.append([start, start + duration - 1])
+		start += duration
+	time_ranges[-1][1] = end
+	return time_ranges
+
+def TimeRangeDuration(r):
+	return r[1] - r[0] + 1
+
+def TotalDuration(time_ranges):
+	duration = 0
+	for r in time_ranges:
+		duration += TimeRangeDuration(r)
+	return duration
+
+def SplitTimeRangesByInterval(time_ranges, interval):
+	new_ranges = []
+	for r in time_ranges:
+		duration = TimeRangeDuration(r)
+		n = duration / interval
+		n = int(round(n, 0))
+		new_ranges += SplitSingleTimeRangeIntoN(r, n)
+	return new_ranges
+
+def SplitTimeRangesIntoN(time_ranges, n, min_interval):
+	if n <= len(time_ranges):
+		return time_ranges
+	duration = TotalDuration(time_ranges)
+	interval = duration / n
+	if interval < min_interval:
+		interval = min_interval
+	return SplitTimeRangesByInterval(time_ranges, interval)
+
+def RecombineTimeRanges(tr):
+	new_tr = copy.deepcopy(tr)
+	n = len(new_tr)
+	i = 1
+	while i < len(new_tr):
+		# if prev end + 1 == cur start, combine them
+		if new_tr[i - 1][1] + 1 == new_tr[i][0]:
+			new_tr[i][0] = new_tr[i - 1][0]
+			del new_tr[i - 1]
+		else:
+			i += 1
+	return new_tr
+
+def OpenTimeRangeEnds(time_ranges, min_time, max_time):
+	if time_ranges[0][0] <= min_time:
+		time_ranges[0][0] = None
+	if time_ranges[-1][1] >= max_time:
+		time_ranges[-1][1] = None
+
+def BadTimeStr(time_str):
+	raise Exception(f"perf command bad time option: '{time_str}'\nCheck also 'time of first sample' and 'time of last sample' in perf script --header-only")
+
+def ValidateTimeRanges(time_ranges, time_str):
+	n = len(time_ranges)
+	for i in range(n):
+		start = time_ranges[i][0]
+		end   = time_ranges[i][1]
+		if i != 0 and start <= time_ranges[i - 1][1]:
+			BadTimeStr(time_str)
+		if start > end:
+			BadTimeStr(time_str)
+
+def TimeVal(s, dflt):
+	s = s.strip()
+	if s == "":
+		return dflt
+	a = s.split(".")
+	if len(a) > 2:
+		raise Exception(f"Bad time value'{s}'")
+	x = int(a[0])
+	if x < 0:
+		raise Exception("Negative time not allowed")
+	x *= 1000000000
+	if len(a) > 1:
+		x += int((a[1] + "000000000")[:9])
+	return x
+
+def BadCPUStr(cpu_str):
+	raise Exception(f"perf command bad cpu option: '{cpu_str}'\nCheck also 'nrcpus avail' in perf script --header-only")
+
+def ParseTimeStr(time_str, min_time, max_time):
+	if time_str == None or time_str == "":
+		return [[min_time, max_time]]
+	time_ranges = []
+	for r in time_str.split():
+		a = r.split(",")
+		if len(a) != 2:
+			BadTimeStr(time_str)
+		try:
+			start = TimeVal(a[0], min_time)
+			end   = TimeVal(a[1], max_time)
+		except:
+			BadTimeStr(time_str)
+		time_ranges.append([start, end])
+	ValidateTimeRanges(time_ranges, time_str)
+	return time_ranges
+
+def ParseCPUStr(cpu_str, nr_cpus):
+	if cpu_str == None or cpu_str == "":
+		return [-1]
+	cpus = []
+	for r in cpu_str.split(","):
+		a = r.split("-")
+		if len(a) < 1 or len(a) > 2:
+			BadCPUStr(cpu_str)
+		try:
+			start = int(a[0].strip())
+			if len(a) > 1:
+				end = int(a[1].strip())
+			else:
+				end = start
+		except:
+			BadCPUStr(cpu_str)
+		if start < 0 or end < 0 or end < start or end >= nr_cpus:
+			BadCPUStr(cpu_str)
+		cpus.extend(range(start, end + 1))
+	cpus = list(set(cpus)) # Remove duplicates
+	cpus.sort()
+	return cpus
+
+class ParallelPerf():
+
+	def __init__(self, a):
+		for arg_name in vars(a):
+			setattr(self, arg_name, getattr(a, arg_name))
+		self.orig_nr = self.nr
+		self.orig_cmd = list(self.cmd)
+		self.perf = self.cmd[0]
+		if os.path.exists(self.output_dir):
+			raise Exception(f"Output '{self.output_dir}' already exists")
+		if self.jobs < 0 or self.nr < 0 or self.interval < 0:
+			raise Exception("Bad options (negative values): try -h option for help")
+		if self.nr != 0 and self.interval != 0:
+			raise Exception("Cannot specify number of time subdivisions and time interval")
+		if self.jobs == 0:
+			self.jobs = NumberOfCPUs()
+		if self.nr == 0 and self.interval == 0:
+			if self.per_cpu:
+				self.nr = 1
+			else:
+				self.nr = self.jobs
+
+	def Init(self):
+		if self.verbosity.debug:
+			print("cmd", self.cmd)
+		self.file_name = DetermineInputFileName(self.cmd)
+		self.hdr = ReadHeader(self.perf, self.file_name)
+		self.hdr_dict = ParseHeader(self.hdr)
+		self.cmd_line = HeaderField(self.hdr_dict, "cmdline")
+
+	def ExtractTimeInfo(self):
+		self.min_time = TimeVal(HeaderField(self.hdr_dict, "time of first sample"), 0)
+		self.max_time = TimeVal(HeaderField(self.hdr_dict, "time of last sample"), 0)
+		self.time_str = ExtractPerfOption(self.cmd, "", "time")
+		self.time_ranges = ParseTimeStr(self.time_str, self.min_time, self.max_time)
+		if self.verbosity.debug:
+			print("time_ranges", self.time_ranges)
+
+	def ExtractCPUInfo(self):
+		if self.per_cpu:
+			nr_cpus = int(HeaderField(self.hdr_dict, "nrcpus avail"))
+			self.cpu_str = ExtractPerfOption(self.cmd, "C", "cpu")
+			if self.cpu_str == None or self.cpu_str == "":
+				self.cpus = [ x for x in range(nr_cpus) ]
+			else:
+				self.cpus = ParseCPUStr(self.cpu_str, nr_cpus)
+		else:
+			self.cpu_str = None
+			self.cpus = [-1]
+		if self.verbosity.debug:
+			print("cpus", self.cpus)
+
+	def IsIntelPT(self):
+		return self.cmd_line.find("intel_pt") >= 0
+
+	def SplitTimeRanges(self):
+		if self.IsIntelPT() and self.interval == 0:
+			self.split_time_ranges_for_each_cpu = \
+				SplitTimeRangesByTraceDataDensity(self.time_ranges, self.cpus, self.orig_nr,
+								  self.orig_cmd, self.file_name, self.per_cpu,
+								  self.min_size, self.min_interval, self.verbosity)
+		elif self.nr:
+			self.split_time_ranges_for_each_cpu = [ SplitTimeRangesIntoN(self.time_ranges, self.nr, self.min_interval) ]
+		else:
+			self.split_time_ranges_for_each_cpu = [ SplitTimeRangesByInterval(self.time_ranges, self.interval) ]
+
+	def CheckTimeRanges(self):
+		for tr in self.split_time_ranges_for_each_cpu:
+			# Re-combined time ranges should be the same
+			new_tr = RecombineTimeRanges(tr)
+			if new_tr != self.time_ranges:
+				if self.verbosity.debug:
+					print("tr", tr)
+					print("new_tr", new_tr)
+				raise Exception("Self test failed!")
+
+	def OpenTimeRangeEnds(self):
+		for time_ranges in self.split_time_ranges_for_each_cpu:
+			OpenTimeRangeEnds(time_ranges, self.min_time, self.max_time)
+
+	def CreateWorkList(self):
+		self.worklist = CreateWorkList(self.cmd, self.pipe_to, self.output_dir, self.cpus, self.split_time_ranges_for_each_cpu)
+
+	def PerfDataRecordedPerCPU(self):
+		if "--per-thread" in self.cmd_line.split():
+			return False
+		return True
+
+	def DefaultToPerCPU(self):
+		# --no-per-cpu option takes precedence
+		if self.no_per_cpu:
+			return False
+		if not self.PerfDataRecordedPerCPU():
+			return False
+		# Default to per-cpu for Intel PT data that was recorded per-cpu,
+		# because decoding can be done for each CPU separately.
+		if self.IsIntelPT():
+			return True
+		return False
+
+	def Config(self):
+		self.Init()
+		self.ExtractTimeInfo()
+		if not self.per_cpu:
+			self.per_cpu = self.DefaultToPerCPU()
+		if self.verbosity.debug:
+			print("per_cpu", self.per_cpu)
+		self.ExtractCPUInfo()
+		self.SplitTimeRanges()
+		if self.verbosity.self_test:
+			self.CheckTimeRanges()
+		# Prefer open-ended time range to starting / ending with min_time / max_time resp.
+		self.OpenTimeRangeEnds()
+		self.CreateWorkList()
+
+	def Run(self):
+		if self.dry_run:
+			print(len(self.worklist),"jobs:")
+			for w in self.worklist:
+				print(w.Command())
+			return True
+		result = RunWork(self.worklist, self.jobs, verbosity=self.verbosity)
+		if self.verbosity.verbose:
+			print(glb_prog_name, "done")
+		return result
+
+def RunParallelPerf(a):
+	pp = ParallelPerf(a)
+	pp.Config()
+	return pp.Run()
+
+def Main(args):
+	ap = argparse.ArgumentParser(
+		prog=glb_prog_name, formatter_class = argparse.RawDescriptionHelpFormatter,
+		description =
+"""
+Run a perf script command multiple times in parallel, using perf script options
+--cpu and --time so that each job processes a different chunk of the data.
+""",
+		epilog =
+"""
+Follow the options by '--' and then the perf script command e.g.
+
+	$ perf record -a -- sleep 10
+	$ parallel-perf.py --nr=4 -- perf script --ns
+	All jobs finished successfully
+	$ tree parallel-perf-output/
+	parallel-perf-output/
+	├── time-range-0
+	│   ├── cmd.txt
+	│   └── out.txt
+	├── time-range-1
+	│   ├── cmd.txt
+	│   └── out.txt
+	├── time-range-2
+	│   ├── cmd.txt
+	│   └── out.txt
+	└── time-range-3
+	    ├── cmd.txt
+	    └── out.txt
+	$ find parallel-perf-output -name cmd.txt | sort | xargs grep -H .
+	parallel-perf-output/time-range-0/cmd.txt:perf script --time=,9466.504461499 --ns
+	parallel-perf-output/time-range-1/cmd.txt:perf script --time=9466.504461500,9469.005396999 --ns
+	parallel-perf-output/time-range-2/cmd.txt:perf script --time=9469.005397000,9471.506332499 --ns
+	parallel-perf-output/time-range-3/cmd.txt:perf script --time=9471.506332500, --ns
+
+Any perf script command can be used, including the use of perf script options
+--dlfilter and --script, so that the benefit of running parallel jobs
+naturally extends to them also.
+
+If option --pipe-to is used, standard output is first piped through that
+command. Beware, if the command fails (e.g. grep with no matches), it will be
+considered a fatal error.
+
+Final standard output is redirected to files named out.txt in separate
+subdirectories under the output directory. Similarly, standard error is
+written to files named err.txt. In addition, files named cmd.txt contain the
+corresponding perf script command. After processing, err.txt files are removed
+if they are empty.
+
+If any job exits with a non-zero exit code, then all jobs are killed and no
+more are started. A message is printed if any job results in a non-empty
+err.txt file.
+
+There is a separate output subdirectory for each time range. If the --per-cpu
+option is used, these are further grouped under cpu-n subdirectories, e.g.
+
+	$ parallel-perf.py --per-cpu --nr=2 -- perf script --ns --cpu=0,1
+	All jobs finished successfully
+	$ tree parallel-perf-output
+	parallel-perf-output/
+	├── cpu-0
+	│   ├── time-range-0
+	│   │   ├── cmd.txt
+	│   │   └── out.txt
+	│   └── time-range-1
+	│       ├── cmd.txt
+	│       └── out.txt
+	└── cpu-1
+	    ├── time-range-0
+	    │   ├── cmd.txt
+	    │   └── out.txt
+	    └── time-range-1
+	        ├── cmd.txt
+	        └── out.txt
+	$ find parallel-perf-output -name cmd.txt | sort | xargs grep -H .
+	parallel-perf-output/cpu-0/time-range-0/cmd.txt:perf script --cpu=0 --time=,9469.005396999 --ns
+	parallel-perf-output/cpu-0/time-range-1/cmd.txt:perf script --cpu=0 --time=9469.005397000, --ns
+	parallel-perf-output/cpu-1/time-range-0/cmd.txt:perf script --cpu=1 --time=,9469.005396999 --ns
+	parallel-perf-output/cpu-1/time-range-1/cmd.txt:perf script --cpu=1 --time=9469.005397000, --ns
+
+Subdivisions of time range, and cpus if the --per-cpu option is used, are
+expressed by the --time and --cpu perf script options respectively. If the
+supplied perf script command has a --time option, then that time range is
+subdivided, otherwise the time range given by 'time of first sample' to
+'time of last sample' is used (refer perf script --header-only). Similarly, the
+supplied perf script command may provide a --cpu option, and only those CPUs
+will be processed.
+
+To prevent time intervals becoming too small, the --min-interval option can
+be used.
+
+Note there is special handling for processing Intel PT traces. If an interval is
+not specified and the perf record command contained the intel_pt event, then the
+time range will be subdivided in order to produce subdivisions that contain
+approximately the same amount of trace data. That is accomplished by counting
+double-quick (--itrace=qqi) samples, and choosing time ranges that encompass
+approximately the same number of samples. In that case, time ranges may not be
+the same for each CPU processed. For Intel PT, --per-cpu is the default, but
+that can be overridden by --no-per-cpu. Note, for Intel PT, double-quick
+decoding produces 1 sample for each PSB synchronization packet, which in turn
+come after a certain number of bytes output, determined by psb_period (refer
+perf Intel PT documentation). The minimum number of double-quick samples that
+will define a time range can be set by the --min_size option, which defaults to
+64.
+""")
+	ap.add_argument("-o", "--output-dir", default="parallel-perf-output", help="output directory (default 'parallel-perf-output')")
+	ap.add_argument("-j", "--jobs", type=int, default=0, help="maximum number of jobs to run in parallel at one time (default is the number of CPUs)")
+	ap.add_argument("-n", "--nr", type=int, default=0, help="number of time subdivisions (default is the number of jobs)")
+	ap.add_argument("-i", "--interval", type=float, default=0, help="subdivide the time range using this time interval (in seconds e.g. 0.1 for a tenth of a second)")
+	ap.add_argument("-c", "--per-cpu", action="store_true", help="process data for each CPU in parallel")
+	ap.add_argument("-m", "--min-interval", type=float, default=glb_min_interval, help=f"minimum interval (default {glb_min_interval} seconds)")
+	ap.add_argument("-p", "--pipe-to", help="command to pipe output to (optional)")
+	ap.add_argument("-N", "--no-per-cpu", action="store_true", help="do not process data for each CPU in parallel")
+	ap.add_argument("-b", "--min_size", type=int, default=glb_min_samples, help="minimum data size (for Intel PT in PSBs)")
+	ap.add_argument("-D", "--dry-run", action="store_true", help="do not run any jobs, just show the perf script commands")
+	ap.add_argument("-q", "--quiet", action="store_true", help="do not print any messages except errors")
+	ap.add_argument("-v", "--verbose", action="store_true", help="print more messages")
+	ap.add_argument("-d", "--debug", action="store_true", help="print debugging messages")
+	cmd_line = list(args)
+	try:
+		split_pos = cmd_line.index("--")
+		cmd = cmd_line[split_pos + 1:]
+		args = cmd_line[:split_pos]
+	except:
+		cmd = None
+		args = cmd_line
+	a = ap.parse_args(args=args[1:])
+	a.cmd = cmd
+	a.verbosity = Verbosity(a.quiet, a.verbose, a.debug)
+	try:
+		if a.cmd == None:
+			if len(args) <= 1:
+				ap.print_help()
+				return True
+			raise Exception("Command line must contain '--' before perf command")
+		return RunParallelPerf(a)
+	except Exception as e:
+		print("Fatal error: ", str(e))
+		if a.debug:
+			raise
+		return False
+
+if __name__ == "__main__":
+	if not Main(sys.argv):
+		sys.exit(1)