DMARC-Filter:	OpenDMARC Filter v1.4.2 delorie.com 50JGdndU1791064
Authentication-Results:	delorie.com; dmarc=pass (p=none dis=none) header.from=cygwin.com
Authentication-Results:	delorie.com; spf=pass smtp.mailfrom=cygwin.com
DKIM-Filter:	OpenDKIM Filter v2.11.0 delorie.com 50JGdndU1791064
Authentication-Results:	delorie.com;
	dkim=pass (1024-bit key, unprotected) header.d=cygwin.com header.i=@cygwin.com header.a=rsa-sha256 header.s=default header.b=V6eZYarn
X-Recipient:	archive-cygwin AT delorie DOT com
DKIM-Filter:	OpenDKIM Filter v2.11.0 sourceware.org 841FA3858C52
DKIM-Signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1737304787;
	bh=IolMk8oMkqYOsYeDVIBsDHFTyL0j9CVLUVad3rsPMmg=;
	h=Date:Subject:To:References:In-Reply-To:List-Id:List-Unsubscribe:
	List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc:
	From;
	b=V6eZYarnuSEEv+HAOJ3l4XPlsfee47Zc8g4jX9qJRQVStFGiwroHani3TPHAP73XK
	cwz9Hy/fUF8ox3P2zcJiDPEHSltA8VOoVh7JX3KcOR5M3IVPzzIn9jYeM/+ZiTDo0q
	2QImGrbJdfY03MrQVGuSxBFTV5Gcauo2KS9dWOzM=
X-Original-To:	cygwin AT cygwin DOT com
Delivered-To:	cygwin AT cygwin DOT com
DMARC-Filter:	OpenDMARC Filter v1.4.2 sourceware.org D30E23858C50
ARC-Filter:	OpenARC Filter v1.0.0 sourceware.org D30E23858C50
ARC-Seal:	i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1737304724; cv=none;
	b=Sbw/V4nPUW8sPIx7pyZFO46/GQHgicdRuM5KnHaLAKRrSglVtPTzjwhXfc9CsDLHdTQ054ukbwmaqByWwVPfRtEFgRj7iOW/ZaB2WFEiO5c1Ay88E3LFas3z4j1//QNhvGYrekC5iT6Cle7jgX7j+zyUZZb2degf4tXomrRmKCA=
ARC-Message-Signature:	i=1; a=rsa-sha256; d=sourceware.org; s=key;
	t=1737304724; c=relaxed/simple;
	bh=ZK2Ac4nQ4skxiIvfmNEY+N65yWtkvmWVOQhooFY4VPY=;
	h=Message-ID:Date:MIME-Version:From:Subject:To:DKIM-Signature;
	b=jJ/XatUABErKNu5LZNK8m1UnO/LREZ/TVGqrhcIjKTb4a7NdkJbAqgTfA/kq9GETMbaGmqgPYXNqAhozDMsqpyOarYI3RLy0K8znDzBMNdhYDeHuNBECeUEECpLt3nESV5ivMXEhl+YsxEh2Oh+fnSEIenpAMOVXaSyXg/i0Sjc=
ARC-Authentication-Results:	i=1; server2.sourceware.org
DKIM-Filter:	OpenDKIM Filter v2.11.0 sourceware.org D30E23858C50
Message-ID:	<388acd4c-0ea6-4662-ae2e-e96b7ec2f437@SystematicSW.ab.ca>
Date:	Sun, 19 Jan 2025 09:38:41 -0700
MIME-Version:	1.0
User-Agent:	Mozilla Thunderbird
Subject:	Re: [Bug] time(0x0) call extremely slow?
To:	cygwin AT cygwin DOT com
References:	<CANM0SV3a4vVv9FTbdFawx28G_Z6Vo5M2=pcgADOZo3-Xu4+ciA AT mail DOT gmail DOT com>
Organization:	Systematic Software
In-Reply-To:	<CANM0SV3a4vVv9FTbdFawx28G_Z6Vo5M2=pcgADOZo3-Xu4+ciA@mail.gmail.com>
X-Rspamd-Queue-Id:	1E57A6000C
X-Stat-Signature:	j3s4n3jxagaqde6xypxfa6wc3cc7a3j8
X-Rspamd-Server:	rspamout03
X-Session-Marker:	427269616E2E496E676C69734053797374656D6174696353572E61622E6361
X-Session-ID:	U2FsdGVkX1/lZf/kTrKgQutc9kFaHynn+Ph4F5wtLSc=
X-HE-Tag:	1737304722-645908
X-HE-Meta:	U2FsdGVkX1+/hOSlOc6J5Rg77uAmysrcfSqUjz4Zugek2eG2DbWy8rxKDO1C3ZrzQW7bRJHW4JnlXj4gfr5MmdXue4uDJT6C+dCfMSm9oH6trkS3QRxQiws+WNcez40mtC+XS4dZibttDca5RhJ42tZI2ZTQ8eMHbl4wYxborcYR7e3U1HpRKqmO7p9ZzFSCF/GtOQcLmUEUMVgkRlN+J/i2oeqA7K2gl+wcBQVCTs0E4FERW2jOgkBpEBghT/r8GOCv3xHo3bS27AcPrxOgpmyavCfEY/RPHMdpQ5usKCsB50PjtpMDtsPcfzWWOn/cZGxfuZaAr9ubG+3hD5iVLEiapPLRezyN
X-BeenThere:	cygwin AT cygwin DOT com
X-Mailman-Version:	2.1.30
List-Id:	General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe:	<https://cygwin.com/mailman/options/cygwin>,
	<mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive:	<https://cygwin.com/pipermail/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe:	<https://cygwin.com/mailman/listinfo/cygwin>,
	<mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From:	Brian Inglis via Cygwin <cygwin AT cygwin DOT com>
Reply-To:	cygwin AT cygwin DOT com
Cc:	Brian Inglis <Brian DOT Inglis AT SystematicSW DOT ab DOT ca>
Errors-To:	cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com
Sender:	"Cygwin" <cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com>
X-MIME-Autoconverted:	from base64 to 8bit by delorie.com id 50JGdndU1791064

On 2025-01-19 05:55, Devste Devste via Cygwin wrote:
> strace -o strace.log dirname -- /some/path/here
> 
> Cygwin via Git for Windows 2.47.x
> Windows 10
> 
> I see:
>> 3249 60966 [main] dirname 31200 time: 1736590460 = time(0x0)
> 
> On average it shows between 2000-4000 duration (I'm using Cloudflare's
> ntp servers) which seems fishy to me, as this shouldn't be that slow?

Remember this is a C program, running under C++ program strace, running under a 
C++ emulator cygwin, where other processes can run, including overhead which 
includes its own timing calls, and I don't believe strace takes account of that, 
so you are seeing wall clock durations and time counters, in µs I believe.

I see these times, normally ~200us, although I do not know why time is being 
called in dirname?

$ grep time ../dirname.strace
   218   27334 [main] dirname (2604) time: 1737301093 = time(0x0)
   181   29475 [main] dirname (2604) time: 1737301093 = time(0x0)
  4352  101621 [main] dirname 50118 time: 1737301093 = time(0x0)

These all appear to be converted from SystemTimePreciseAsFileTime; for accurate 
timing, you probably have to use rdtsc instructions directly to capture the 
times in a buffer; and calibrate using SystemTimePreciseAsFileTime, and do any 
conversions, after the fact.

[Unless you are running a local Windows NTP server to discipline the time, w32tm 
service with DC time, or upstream remote NTP servers, are mostly irrelevant as 
they randomly bump the system time towards UTC.]

-- 
Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retrancher  but when there is no more to cut
                                 -- Antoine de Saint-Exupéry

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple

- Raw text -