Date: Wed, 04 Mar 1998 18:58:44 -0800 (PST) From: Simon Shapiro <shimon@simon-shapiro.org> To: Evan Champion <evanc@synapse.net> Cc: current@FreeBSD.ORG, Mike Smith <mike@smith.net.au>, Matthew Thyer <Matthew.Thyer@dsto.defence.gov.au> Subject: Re: silo overflows (Was Re: 3.0-RELEASE?) Message-ID: <XFMail.980304185844.shimon@simon-shapiro.org> In-Reply-To: <053601bd47dd$6cedf300$c9252fce@cello.synapse.net>
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On 05-Mar-98 Evan Champion wrote: >>This happens a lot as after several hours (2 or 3) of using >>ijppp and XFree86 the count of FIFO overflows can be around 100. > > > I have a Pentium Pro 200 with 16650's (and the 16650's are detected) and > during a full install of FreeBSD over 128kbps ISDN (230.4kbps port speed) > I > would get around 700 FIFO overflows. Someone would have to do a lot of > convincing to get me to believe the driver is working properly when a > machine like that can't handle a 128kbps datastream in single user > mode... Assume you are doing something like FTP of packages-current. You are reading about 16 kilobytes per second, which is just about 1,142 interrupts per second (assuming a 16 myte FIFO and 14 byte treshold. Every 1KB, you write to disk, so now we have 1,160 interrupts per second. Add 10% ACK on the FTP connection, HZ heartbeat, and you have 1,400 interrupts per second. Say 2,000 interrupts/Sec. A P6-200 will be safe in this regard. In a RT O/S this will give us about 500us per interrupt. What do you think? ---------- Sincerely Yours, Simon Shapiro Shimon@Simon-Shapiro.ORG Voice: 503.799.2313 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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