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Date: Mon, 12 Nov 2001 16:06:30 -0500
From: Christopher Faylor <cgf AT redhat DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: cygwin vfork
Message-ID: <20011112210630.GA25356@redhat.com>
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References: <3BF018AD DOT 9000105 AT ece DOT gatech DOT edu>
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On Mon, Nov 12, 2001 at 01:45:01PM -0500, Charles Wilson wrote:
>Seen on the XEmacs list:
>
>> In general the cygwin build is slower, I think this is for 3 main
>> reasons:
>>
>> 1) gcc optimization is not as good as MSVC
>> 2) The cygwin portability layer adds a lot of overhead especially
>> wrt file handling.
>> 3) The cygwin implementation of fork-and-exec doesn't jive well with
>> the VM size of xemacs. Supposedly a real vfork is in the works for
>> cygwin but I can't attest to its functionality.
>
>Does #3 make any sense?  I thought we *had* a real vfork...perhaps it 
>doesn't work well with large apps?  Or is the author just blowing smoke?

We have had a sort-of-vfork that should be faster than fork since 1.3.3,
I think.  No idea what the VM goobledy-gook is referring to.

Cygwin's vfork is just black magic that eventually results in running
spawn(P_NOWAIT) rather than fork/exec.

cgf

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