From owner-freebsd-alpha Sun Sep 19 11:52:17 1999 Delivered-To: freebsd-alpha@freebsd.org Received: from dingo.cdrom.com (castles556.castles.com [208.214.165.120]) by hub.freebsd.org (Postfix) with ESMTP id 00CBA14C3B for ; Sun, 19 Sep 1999 11:52:13 -0700 (PDT) (envelope-from mike@dingo.cdrom.com) Received: from dingo.cdrom.com (localhost [127.0.0.1]) by dingo.cdrom.com (8.9.3/8.8.8) with ESMTP id LAA25777; Sun, 19 Sep 1999 11:43:53 -0700 (PDT) (envelope-from mike@dingo.cdrom.com) Message-Id: <199909191843.LAA25777@dingo.cdrom.com> X-Mailer: exmh version 2.0.2 2/24/98 To: Jason Thorpe Cc: wwoods@cybcon.com, freebsd-alpha@FreeBSD.ORG Subject: Re: Silo Overflows on Alpha...... In-reply-to: Your message of "Sun, 19 Sep 1999 11:45:22 PDT." <199909191845.LAA17531@lestat.nas.nasa.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sun, 19 Sep 1999 11:43:52 -0700 From: Mike Smith Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > On Sun, 19 Sep 1999 04:58:44 -0700 (PDT) > William Woods wrote: > > > I have an Alphastation 200 4/233 running 3.2-R (I am TRYING to cvsup to > > 3.3-Stable) and I keep getting silo overflows when connected to the net with an > > external modem at anything over 9600. > > NetBSD's `com' driver uses a split interrupt scheme to help this a little, > and can do 56k on the Alpha pretty easily. However, above that, it still > gets overruns due to the OSF/1 PALcode's interrupt scheme; all interrupts > are routed to what is effectively one interrupt level in the PSL sense; there > are actually two, but since you have no way of knowing what processor IRQ > is routed to which IPL, and no way to program the routing yourself, you > have to block both in order to block "I/O interrupts". The Linux folks seem to take over the interrupt hardware themselves; this is probably the only way to get any sort of decent performance, but I'm not sure how far-reaching the implications of this are. -- \\ The mind's the standard \\ Mike Smith \\ of the man. \\ msmith@freebsd.org \\ -- Joseph Merrick \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message