From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Thu,  3 Sep 1998 10:23:10 -0400
From: jmk@plan9.bell-labs.com jmk@plan9.bell-labs.com
Subject: [9fans] Find command
Topicbox-Message-UUID: 7e93d39e-eac8-11e9-9e20-41e7f4b1d025
Message-ID: <19980903142310.vQwl_UZ9BX0i8_CJnoJ3doaHUPz7ZBXepAWxwbqVWQo@z>

in plan9, TSTKSIZ on the x86 is rather small (10) and located awkwardly in
the address space - you can't increase it without also moving the location of
the user stack and there are some places this value is known (e.g. the alef
runtime):

	#define	USERADDR	0xC0000000		/* struct User */
	#define	TSTKTOP		USERADDR		/* end of new stack in sysexec */
	#define TSTKSIZ 	10
	#define	USTKTOP		(TSTKTOP-TSTKSIZ*BY2PG)	/* byte just beyond user stack */

although i don't remember all the details, in order to increase
it a couple of years ago in brazil i moved things around a bit more:

	#define	KZERO		0x80000000		/* base of kernel address space */
	#define	USTKTOP		(KZERO-BY2PG)		/* byte just beyond user stack */
	#define	TSTKTOP		(USTKTOP-USTKSIZE)	/* end of new stack in sysexec */
	#define TSTKSIZ 	100

this was fun as we were running a user-level ip implementation written in alef
at the time.

--jim

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From: forsyth@caldo.demon.co.uk
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To: 9fans@cse.psu.edu
Date: Thu, 3 Sep 1998 08:19:56 BST
Subject: Re: [9fans] Find command
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>>The only limit on arglist size in plan 9 is
>>total virtual memory available.

it's limited to TSTKSIZ*BY2PG during the transfer between images,
but it would be better to remove the restriction than to reinstate xargs.