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Newsgroups: comp.os.386bsd.development Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!elroy.jpl.nasa.gov!swrinde!cs.utexas.edu!uunet!ihz.compuserve.com!mdickson From: mdickson@csi.compuserve.com (Michael Dickson) Subject: Re: Kernel is too big for 640K In-Reply-To: pk@cs.few.eur.nl's message of Thu, 20 May 1993 12:38:08 GMT Message-ID: <MDICKSON.93May20170314@mike.csi.compuserve.com> Sender: news@csi.compuserve.com (Usenet News) Reply-To: m.dickson@csi.CompuServe.com Organization: CompuServe, Inc. References: <1993May17.101101.1940@yvax.byu.edu> <1993May20.123808.18947@cs.few.eur.nl> Date: Thu, 20 May 1993 21:03:24 GMT Lines: 48 In article <1993May20.123808.18947@cs.few.eur.nl> pk@cs.few.eur.nl (Paul Kranenburg) writes: Newsgroups: comp.os.386bsd.development Path: ihz.compuserve.com!uunet!pipex!uknet!mcsun!sun4nl!eur.nl!pk From: pk@cs.few.eur.nl (Paul Kranenburg) Sender: news@cs.few.eur.nl Reply-To: pk@cs.few.eur.nl Organization: Erasmus University Rotterdam References: <1993May17.101101.1940@yvax.byu.edu> Date: Thu, 20 May 1993 12:38:08 GMT Lines: 20 In <1993May17.101101.1940@yvax.byu.edu> bkh@nephi-hbll.byu.edu (Brian K. Holman) writes: >I recompiled the NetBSD Kernel. I increased the number of users >and the number of ptys. I also modified the MAKEDEV script to allow >it to generate ptys beyond 32. When I boot it gives me the message >"Kernel is too big for 640K. Only hope is to link for >1MB". I >assume that this message was put there for a reason. Can someone In this case, another solution seems warranted. Note that the tty structure (in <sys/tty.h> is more than 3K in size, due to the inclusion of 3 "ring buufers" of 1K each. If you configure 32 ptys, this consumes nearly 100K of precious memory in the data segment. I don't think it will be a hard job to replace the static buffers with a call to malloc() somewhere in ttyopen() and a free() in ttyclose(). There may just be snag involved in conjunction with console driver in its current form, though. -pk Paul, I've actually done what you describe and yes there is a problem with the console driver as it exists. I've built systems with as many as 128 ptys (which also requires some library changes so that programs calling forkpty() can use the extra ptys). Other than the problem with the console driver it all works pretty good. I'm going to clean up the code a bit and see if I can't work around the console problem. It really was easy to put in. If there is interest I'll generate some patches after I do the work to fix the console issue. Mike Dickson CompuServe, Incorporated mdickson@csi.compuserve.com