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Differential D4346

hg: wrap the highest layer in the `hg` script possible in trace event
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Authored by durin42 on Aug 21 2018, 5:39 PM.

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indygreg

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hg-reviewers

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rHG5e78c100a215: hg: wrap the highest layer in the `hg` script possible in trace event

Summary

This should help us have a better idea of what "interpreter startup
costs" look like. This does omit the HGUNICODEPEDANTRY block and the
LIBDIR dancing to set up sys.path, but the former is usually off and
the latter is unavoidable and should be very fast. If we get worried
about those cases we can consider open-coding the tracing logic here.

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rHG Mercurial

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durin42 created this revision.Aug 21 2018, 5:39 PM

Herald added a reviewer: hg-reviewers. · View Herald TranscriptAug 21 2018, 5:39 PM

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durin42 added a child revision: D4347: demandimport: instrument python 2 code with trace events.Aug 21 2018, 5:39 PM

indygreg added a subscriber: indygreg.Aug 21 2018, 6:47 PM

indygreg added inline comments.

hg
14–21	I think we want to defer the import until after `reload(sys)`. Keep in mind that importing the sub-module will import the parent one. And the parent one contains code that is somewhat important. But we still want to measure time spent here. This may warrant a one-off hack to record a session ID and raw times here and to feed that into the tracer manually after we've done this extremely early setup.

indygreg requested changes to this revision.Aug 24 2018, 1:12 PM

indygreg added inline comments.

hg
23–30	Attempting to import `hgdemandimport` before this block is wrong, since we may fail to find the `hgdemandimport` package. I think we'll want to record trace events / times in this file explicitly and then generate trace events for them only once the environment is set up. Truth be told, I don't expect much time to be spent between lines 12 and 28 of the current file. So I'm not sure it is worth going through this trouble. Although I would love to be proved wrong!

This revision now requires changes to proceed.Aug 24 2018, 1:12 PM

durin42 edited the summary of this revision. (Show Details)Aug 28 2018, 1:59 PM

durin42 updated this revision to Diff 10620.

I think this is ready? Do I owe you anything else on it?

Closed by commit rHG5e78c100a215: hg: wrap the highest layer in the `hg` script possible in trace event (authored by durin42). · Explain WhySep 12 2018, 9:49 PM

This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

			Path	Packages
M			hg (50 lines)

Diff	ID	Description	Created	Lint	Unit
Base		Base
Diff 1	10496		Aug 21 2018, 5:39 PM	★	★
Diff 2	10620		Aug 28 2018, 1:59 PM	★	★
Diff 3	10983	rHG5e78c100a21586dfdc622a86537c0a0231652e1d	Aug 21 2018, 3:25 PM	★	★

Commit	Parents	Author	Summary	Date
		Augie Fackler		Aug 21 2018, 3:25 PM

Status	Author	Revision
Closed	durin42	D4350 util: make timedcm require the label
Closed	durin42	D4349 cleanup: make all uses of timedcm specify what they're timing
Closed	durin42	D4348 util: make timedcm context manager also emit trace events
Closed	durin42	D4347 demandimport: instrument python 2 code with trace events
Closed	durin42	D4346 hg: wrap the highest layer in the `hg` script possible in trace event
Closed	durin42	D4345 dispatch: have dispatch.dispatch and dispatch._runcatch emit trace events
Closed	durin42	D4344 tracing: new module to make tracing events in hg easier
Closed	durin42	D4343 tests: add support for emitting trace events to run-tests
Closed	durin42	D4342 contrib: new script to read events from a named pipe and emit catapult traces

Diff 10496

hg

	#!/usr/bin/env python			#!/usr/bin/env python
	#			#
	# mercurial - scalable distributed SCM			# mercurial - scalable distributed SCM
	#			#
	# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>			# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
	#			#
	# This software may be used and distributed according to the terms of the			# This software may be used and distributed according to the terms of the
	# GNU General Public License version 2 or any later version.			# GNU General Public License version 2 or any later version.
	from __future__ import absolute_import			from __future__ import absolute_import

	import os			import os
	import sys			import sys

				from hgdemandimport import tracing
				with tracing.log('hg script'):
	if os.environ.get('HGUNICODEPEDANTRY', False):			if os.environ.get('HGUNICODEPEDANTRY', False):
	try:			try:
	reload(sys)			reload(sys)
	sys.setdefaultencoding("undefined")			sys.setdefaultencoding("undefined")
	except NameError:			except NameError:
	pass			pass
				indygregUnsubmitted Not Done I think we want to defer the import until after `reload(sys)`. Keep in mind that importing the sub-module will import the parent one. And the parent one contains code that is somewhat important. But we still want to measure time spent here. This may warrant a one-off hack to record a session ID and raw times here and to feed that into the tracer manually after we've done this extremely early setup. indygreg: I think we want to defer the import until after `reload(sys)`. Keep in mind that importing the…

	libdir = '@LIBDIR@'			libdir = '@LIBDIR@'

	if libdir != '@' 'LIBDIR' '@':			if libdir != '@' 'LIBDIR' '@':
	if not os.path.isabs(libdir):			if not os.path.isabs(libdir):
	libdir = os.path.join(os.path.dirname(os.path.realpath(__file__)),			libdir = os.path.join(os.path.dirname(os.path.realpath(__file__)),
	libdir)			libdir)
	libdir = os.path.abspath(libdir)			libdir = os.path.abspath(libdir)
	sys.path.insert(0, libdir)			sys.path.insert(0, libdir)
				indygregUnsubmitted Not Done Attempting to import `hgdemandimport` before this block is wrong, since we may fail to find the `hgdemandimport` package. I think we'll want to record trace events / times in this file explicitly and then generate trace events for them only once the environment is set up. Truth be told, I don't expect much time to be spent between lines 12 and 28 of the current file. So I'm not sure it is worth going through this trouble. Although I would love to be proved wrong! indygreg: Attempting to import `hgdemandimport` before this block is wrong, since we may fail to find the…

	# enable importing on demand to reduce startup time			# enable importing on demand to reduce startup time
	try:			try:
	if sys.version_info[0] < 3 or sys.version_info >= (3, 6):			if sys.version_info[0] < 3 or sys.version_info >= (3, 6):
	import hgdemandimport; hgdemandimport.enable()			import hgdemandimport; hgdemandimport.enable()
	except ImportError:			except ImportError:
	sys.stderr.write("abort: couldn't find mercurial libraries in [%s]\n" %			sys.stderr.write("abort: couldn't find mercurial libraries in [%s]\n" %
	' '.join(sys.path))			' '.join(sys.path))
	sys.stderr.write("(check your install and PYTHONPATH)\n")			sys.stderr.write("(check your install and PYTHONPATH)\n")
	sys.exit(-1)			sys.exit(-1)

	from mercurial import dispatch			from mercurial import dispatch
	dispatch.run()			dispatch.run()