From owner-freebsd-current Wed Nov 15 12:13:23 1995 Return-Path: owner-current Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id MAA17827 for current-outgoing; Wed, 15 Nov 1995 12:13:23 -0800 Received: from hutcs.cs.hut.fi (root@hutcs.cs.hut.fi [130.233.192.2]) by freefall.freebsd.org (8.6.12/8.6.6) with SMTP id MAA17818 for ; Wed, 15 Nov 1995 12:13:17 -0800 Received: from shadows.cs.hut.fi by hutcs.cs.hut.fi with SMTP id AA06371 (5.65c8/HUTCS-S 1.4 for ); Wed, 15 Nov 1995 22:11:45 +0200 Received: (hsu@localhost) by shadows.cs.hut.fi (8.6.10/8.6.10) id WAA05574; Wed, 15 Nov 1995 22:11:44 +0200 Date: Wed, 15 Nov 1995 22:11:44 +0200 Message-Id: <199511152011.WAA05574@shadows.cs.hut.fi> From: Heikki Suonsivu To: Bruce Evans Cc: hsu@cs.hut.fi, j@uriah.heep.sax.de, current@FreeBSD.org Subject: Re: ISP state their FreeBSD concerns In-Reply-To: <199511151327.AAA05338@godzilla.zeta.org.au> References: <199511151327.AAA05338@godzilla.zeta.org.au> Sender: owner-current@FreeBSD.org Precedence: bulk Bruce Evans writes: > >Yes, but Bruce, why can't we insert the simple #ifndef? It doesn't > >break anything, but would allow interested people (with a `very > >special setup') to override it from the config file instead of hacking > >the sources over and over again. > > Because ifdefs are evil and simply changing RS_IBUFSIZE is not sufficient. > It must satisfy the following: > > TTYHOG - 2*RS_IBUFSIZE > 0 (much greater, < TTYHOG/2 would be silly) Could it be sensible to make RS_IBUFSIZE ((TTYHOG)/4) ? This would allow tuning TTYHOG value only. It would be a kludge, though. Maybe serial input should be handled differently from other typical tty processing. I do not know enough of the tty code to know whether it is useful to increase TTYHOG value anyway (to me 1k sounds small for any purpose). > RS_IBUFSIZE - 11520 * (1.0/hz + max_softtty_interrupt_latency) >= 0 Btw, lots of ISDN "modems" like ZyXEL's are connected with overclocked 16650/16550 serial ports. I have one at 460.8k. -- Heikki Suonsivu, T{ysikuu 10 C 83/02210 Espoo/FINLAND, hsu@cs.hut.fi home +358-0-8031121 work -4513377 fax -4555276 riippu SN