CONFIG_UNIX98_PTY_COUNT and devfs

CONFIG_UNIX98_PTY_COUNT and devfs

[Frédéric L. W. Meunier]

I used CONFIG_UNIX98_PTY_COUNT=32 and it created
/dev/pty/m[0-255]. Is there any way to make devfs only create
/dev/pty/m[0-31] ?

>From Configure.help:

"When not in use, each additional set of 256 PTYs occupy
approximately 8 KB of kernel memory on 32-bit architectures."

Does that mean it doesn't make any difference if I set
CONFIG_UNIX98_PTY_COUNT=1 or CONFIG_UNIX98_PTY_COUNT=256, and
ONFIG_UNIX98_PTY_COUNT=257 will create 512 entries ?

-- 
http://www.pervalidus.net/contact.html

Re: CONFIG_UNIX98_PTY_COUNT and devfs

[H. Peter Anvin]

Followup to:  <Pine.LNX.4.58.0312170131500.397@pervalidus.dyndns.org>
By author:    =?ISO-8859-1?Q?Fr=E9d=E9ric_L=2E_W=2E_Meunier?= <1@pervalidus.net>
In newsgroup: linux.dev.kernel
>
> I used CONFIG_UNIX98_PTY_COUNT=32 and it created
> /dev/pty/m[0-255]. Is there any way to make devfs only create
> /dev/pty/m[0-31] ?
> 
> From Configure.help:
> 
> "When not in use, each additional set of 256 PTYs occupy
> approximately 8 KB of kernel memory on 32-bit architectures."
> 
> Does that mean it doesn't make any difference if I set
> CONFIG_UNIX98_PTY_COUNT=1 or CONFIG_UNIX98_PTY_COUNT=256, and
> ONFIG_UNIX98_PTY_COUNT=257 will create 512 entries ?
> 

This has absolutely nothing to do with devfs, but Unix98 PTYs
currently come in packs of 256.

	-hpa
-- 
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
If you send me mail in HTML format I will assume it's spam.
"Unix gives you enough rope to shoot yourself in the foot."
Architectures needed: ia64 m68k mips64 ppc ppc64 s390 s390x sh v850 x86-64