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From:	Bernard Dautrevaux <Dautrevaux AT microprocess DOT com>
To:	"'cygwin AT cygwin DOT com'" <cygwin AT cygwin DOT com>
Subject:	RE: Optimizing away "ReadFile" calls when Make calls stat()
Date:	Wed, 14 Feb 2001 11:42:37 +0100
MIME-Version:	1.0
X-Mailer:	Internet Mail Service (5.5.2650.21)

> -----Original Message-----
> From: Christopher Faylor [mailto:cgf AT redhat DOT com]
> Sent: Tuesday, February 13, 2001 11:29 PM
> To: cygwin AT cygwin DOT com
> Subject: Re: Optimizing away "ReadFile" calls when Make calls stat()
> 
> 
> On Tue, Feb 13, 2001 at 05:13:49PM -0500, Puttkammer, Roman wrote:
> >
> >> -----Original Message-----
> >> From: jfaith AT lineo DOT com [mailto:jfaith AT lineo DOT com]
> >> ...
> >> script just did "make --version > /dev/null" one thousand times
> >> ...
> >> Linux: 3 sec.
> >> VMWare running Linux: 9 sec.
> >> DOS (batch file) 18 sec.
> >> Cygwin: 30 sec.
> >
> >AFAIK, fork() tends to be much slower on windows than on most unixes
> >such as solaris or linux.
> 
> There is no real fork on generic Win32.  Cygwin emulates the 
> fork call and
> it is, as a result, very slow.
> 

AFAIK, cygwin is not the only at fault here, the raw Win32 CreateProcess()
call is quite slow also. In our cross-development toolset we only use a
"spawn" call implemented directly on top of ProcessCreate and we see a more
than 10-times performance loss between "fork/exec" on Linux and "spawn" on
NT :-)

Regards,

	Bernard

--------------------------------------------
Bernard Dautrevaux
Microprocess Ingenierie
97 bis, rue de Colombes
92400 COURBEVOIE
FRANCE
Tel:	+33 (0) 1 47 68 80 80
Fax:	+33 (0) 1 47 88 97 85
e-mail:	dautrevaux AT microprocess DOT com
		b DOT dautrevaux AT usa DOT net
-------------------------------------------- 

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