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Is this in some reply to some unasked question? If so, I have to
correct a few mistakes in your explanation. If not, do elaborate why
you felt compelled to send this summary.<br>
<br>
shlomo bauer wrote:
<blockquote
cite="mid:f538f3fa0906201252g24eabdc7v86fb8c7c7b806b37@mail.gmail.com"
type="cite">
<pre wrap="">
Today, this is probably not the case for a variety of reasons --
</pre>
</blockquote>
>From the vfork man page:<br>
<blockquote type="cite">BUGS<br>
It is rather unfortunate that Linux revived this specter
from the past. The BSD man page states: "This system call<br>
will be eliminated when proper system sharing mechanisms are
implemented. Users should not depend on the memory shar‐<br>
ing semantics of vfork() as it will, in that case, be made
synonymous to fork(2)."<br>
</blockquote>
<br>
<blockquote
cite="mid:f538f3fa0906201252g24eabdc7v86fb8c7c7b806b37@mail.gmail.com"
type="cite">
<pre wrap="">notably copy on write semantics of memory; there is little reason to
copy the uproc space (or whatever linux calls it now) since it can be
copied on a write automatically.</pre>
</blockquote>
Except on non-MMU machines, where "fork" is not implemented, and vfork
is the only way to create new processes.<br>
<br>
<blockquote
cite="mid:f538f3fa0906201252g24eabdc7v86fb8c7c7b806b37@mail.gmail.com"
type="cite">
<pre wrap="">vfork is called if exec is called shortly afterwards</pre>
</blockquote>
No. vfork is called if you did not read the man page, or if you wish to
run on non-MMU systems. Aside from "make", I don't know of another
standard process that calls it.<br>
<blockquote
cite="mid:f538f3fa0906201252g24eabdc7v86fb8c7c7b806b37@mail.gmail.com"
type="cite">
<pre wrap=""> -- vfork does no
copying, instead the parent process "loans" its address space to the
child and blocks until the child returns it.</pre>
</blockquote>
Except most vfork implementations today do, in fact, copy the address
space.<br>
<br>
Shachar<br>
<pre class="moz-signature" cols="72">--
Shachar Shemesh
Lingnu Open Source Consulting Ltd.
<a class="moz-txt-link-freetext" href="http://www.lingnu.com">http://www.lingnu.com</a>
</pre>
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