Date: Wed, 04 Mar 1998 19:23:52 -0800 From: Mike Smith <mike@smith.net.au> To: shimon@simon-shapiro.org Cc: Evan Champion <evanc@synapse.net>, 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: <199803050323.TAA23786@dingo.cdrom.com> In-Reply-To: Your message of "Wed, 04 Mar 1998 18:58:44 PST." <XFMail.980304185844.shimon@simon-shapiro.org>
next in thread | previous in thread | raw e-mail | index | archive | help
> > > > 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. Interrupt rate is less significant in this issue than interrupt latency. At 230kbps you have about 43us/character. Without a 16650 datasheet I can't confirm whether the standard FIFO trigger levels are doubled or not; if they are, you have 4 bytes or about 170us between when the interrupt is generated and "too late". Because of the way the sio driver handles interrupts, you want to look for code sections bracketed with disable_intr/enable_intr calls to find possible culprits. > Every > 1KB, you write to disk, so now we have 1,160 interrupts per second. There's no guarantee of this; particularly not if I/O clustering, async or soft updates are enabled. Filesystems are mounted async during an install. -- \\ 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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199803050323.TAA23786>