From owner-freebsd-smp Thu Jul 22 20:42:26 1999 Delivered-To: freebsd-smp@freebsd.org Received: from outmail.utsunomiya-u.ac.jp (outmail.utsunomiya-u.ac.jp [160.12.196.3]) by hub.freebsd.org (Postfix) with ESMTP id D3A801567C for ; Thu, 22 Jul 1999 20:42:17 -0700 (PDT) (envelope-from yokota@zodiac.mech.utsunomiya-u.ac.jp) Received: from zodiac.mech.utsunomiya-u.ac.jp (IDENT:JxF8kQ0cKmvXiA+PbMDtxqplZatpYfU2@zodiac.mech.utsunomiya-u.ac.jp [160.12.42.1]) by outmail.utsunomiya-u.ac.jp (8.9.3/3.7Wpl2) with ESMTP id MAA14917; Fri, 23 Jul 1999 12:41:13 +0900 (JST) Received: from zodiac.mech.utsunomiya-u.ac.jp (zodiac.mech.utsunomiya-u.ac.jp [160.12.42.1]) by zodiac.mech.utsunomiya-u.ac.jp (8.7.6+2.6Wbeta7/3.4W/zodiac-May96) with ESMTP id MAA01470; Fri, 23 Jul 1999 12:45:29 +0900 (JST) Message-Id: <199907230345.MAA01470@zodiac.mech.utsunomiya-u.ac.jp> To: "Richard A. Scheper" Cc: freebsd-smp@freebsd.org, yokota@zodiac.mech.utsunomiya-u.ac.jp Subject: Re: SMP + XDM = keyboard lockup In-reply-to: Your message of "Thu, 22 Jul 1999 21:33:34 -0400." <3797C66E.B9382583@toad.net> References: <199907221845.LAA10738@usr05.primenet.com> <3797C66E.B9382583@toad.net> Date: Fri, 23 Jul 1999 12:45:28 +0900 From: Kazutaka YOKOTA Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org It is true that switching between X and text vtys fast by hitting CTL-ALT-Fx repeatedly may cause keyboard lockup. You can lock up the keyboard if you try to switch between them at the *wrong* moment. For example, many people have reported the keyboard lockup when they tried to switch vtys while the X server is starting up. VT switching is a tricky business and the XFree86 servers and syscons, from time to time, do not see each other in eye to eye... This is not I/O contention. It is an algorithm problem. # This, I believe, is mostly fixed in 4.0-CURRENT. But, I do not believe this is the cause of your problem. Because it is the xdm/X server alone that is switching vtys when your keyboard lockup happens. You, the user, are not switching vtys when this is happening. Nor over-loaded I/O is the cause; the X server alone is exercising inb()/outb() when your lockup happens. There is no I/O contention. Kazu >It looks like your suspiscions are correct. After further attempts at >starting >xdm from a root seesion, it does in fact hang more often than not. Perhaps >I was just "lucky" and it only worked with a quiet system. > >I'll try the ps test and see what I get > >-Rich > >Terry Lambert wrote: > >> > Wow! That's a lot to chew and mostly over my head, but a couple of >> > questions.. >> > >> > If what you say is true, then wouldn't I have toruble running xdm even >> > from a root login after the boot process is over? I don't. >> >> No, not if the system is relatively quiescent. >> >> As I told Nate, you should be able to easily test this by loading >> the I/O system (preferrably *not* your disks) and bouncing the >> console in and out of X using ctrl-alt-F1/[ctrl-]alt-F4. If it >> locks up, the problem has been identified. [...] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message