Path: utzoo!dciem!array!colin
From: colin@array.UUCP (Colin Plumb)
Newsgroups: comp.arch
Subject: Re: vfork (was Re: Paging page tables)
Message-ID: <180@array.UUCP>
Date: 14 Jul 90 04:58:32 GMT
References: <920@dgis.dtic.dla.mil> <5830@titcce.cc.titech.ac.jp> <5DL4SPD@xds13.ferranti.com> <5855@titcce.cc.titech.ac.jp>
Organization: Array Systems Computing, Inc., Toronto, Ontario, CANADA
Lines: 22

I'd just like to point out that Unix can already run out of swap space
at invconvenient times.  I haven't tested it, for obvious reasons, but:

int recurse(int i)
{
	return 1 + recurse(i+1);	/* Foil simple tail-recursion */
}
int main(void)
{
	while (malloc(65536))
		;
	recurse(0);
}

Should blow up on anything that dynamically grows the stack.  So by allowing
a process to die if it hits a bad COW case we aren't breaking the semantics
too badly, although obviously the situation should be avoided if at all
possible.

Is my reasoning wrong?
-- 
	-Colin