Date: Sun, 19 Sep 1999 11:43:52 -0700 From: Mike Smith <mike@smith.net.au> To: Jason Thorpe <thorpej@nas.nasa.gov> Cc: wwoods@cybcon.com, freebsd-alpha@FreeBSD.ORG Subject: Re: Silo Overflows on Alpha...... Message-ID: <199909191843.LAA25777@dingo.cdrom.com> In-Reply-To: Your message of "Sun, 19 Sep 1999 11:45:22 PDT." <199909191845.LAA17531@lestat.nas.nasa.gov>
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> On Sun, 19 Sep 1999 04:58:44 -0700 (PDT) > William Woods <wwoods@cybcon.com> 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
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