From owner-freebsd-current Thu Sep 24 15:53:11 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA03906 for freebsd-current-outgoing; Thu, 24 Sep 1998 15:53:11 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from nomis.simon-shapiro.org (nomis.simon-shapiro.org [209.86.126.163]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id PAA03867 for ; Thu, 24 Sep 1998 15:52:51 -0700 (PDT) (envelope-from shimon@simon-shapiro.org) Received: (qmail 4464 invoked by uid 1000); 24 Sep 1998 23:56:47 -0000 Message-ID: X-Mailer: XFMail 1.3 [p0] on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <199809242030.NAA00623@dingo.cdrom.com> Date: Thu, 24 Sep 1998 19:56:47 -0400 (EDT) X-Face: (&r=uR0&yvh>h^ZL4"-TH61PD}/|Y'~58Z# Gz&BK'&uLAf:2wLb~L7YcWfau{;N(#LR2)\i.l8'ZqVhv~$rNx$]Om6Sv36S'\~5m/U'"i/L)&t$R0&?,)tm0l5xZ!\hZU^yMyCdt!KTcQ376cCkQ^Q_n.GH;Dd-q+ O51^+.K-1Kq?WsP9;cw-Ki+b.iY-5@3!YB5{I$h;E][Xlg*sPO61^5=:5k)JdGet,M|$"lq!1!j_>? $0Yc? Reply-To: shimon@simon-shapiro.org Organization: The Simon Shapiro Foundation From: Simon Shapiro To: Mike Smith Subject: Re: options DPT_LOST_IRQ Cc: current@FreeBSD.ORG, bde@FreeBSD.ORG, "Justin T.Gibbs" Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Mike Smith, On 24-Sep-98 you wrote: > > >This option is necessary due to interrupts being eaten by the serial > > >driver 'fast interrupt' code (which in some cases blocks interrupts > > >longer than the DPT assert them). > > > > Wow. I thought that the fast interrupt code could only cause > > interrupts > > to be deferred, never eaten. Did anyone ever talk to Bruce about this? > > I'd hate to have a situation where lots of drivers each have their own > > little timeout handler to deal with this problem. > > Yes; the FAST_INTR() code basically looks like: > > fastintr: <- entry with PSL_I clear, interrupts masked > call handler <- handler runs with interrupts masked > sti <- reenable interrupts > rti > > (I've left a lot out, obviously.) > > I actually thought as you did when I read Eivind's mail, but rereading > the code this is actually the case. > > For all their efficiency benefits, I think fast interrupts are Evil. I do not know about Evil, but I have a dislike for undeterministic systems... > > > -- > \\ Sometimes you're ahead, \\ Mike Smith > \\ sometimes you're behind. \\ mike@smith.net.au > \\ The race is long, and in the \\ msmith@freebsd.org > \\ end it's only with yourself. \\ msmith@cdrom.com > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-current" in the body of the message Sincerely Yours, Shimon@Simon-Shapiro.ORG 770.265.7340 Simon Shapiro Unwritten code has no bugs and executes at twice the speed of mouth To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message