Date: Sun, 29 Jun 1997 20:05:50 +1000 From: Bruce Evans <bde@zeta.org.au> To: bde@zeta.org.au, Shimon@i-Connect.Net Cc: bmcgover@cisco.com, hackers@FreeBSD.ORG Subject: Re: Clists limited to 1024 bytes? Message-ID: <199706291005.UAA29898@godzilla.zeta.org.au>
next in thread | raw e-mail | index | archive | help
>> Anyway, 19200 bps is not a heavy load unless there are a lot of active >> ports. With 32 active 16550 ports it would be fairly heavy, but still >> gives less than 6% of the throughput of a single 10Mb/s ethernet. > >I was thinking more (on a 16550) about what happens at 115,200, 230,400, >and more. These are speeds we see already today with ISDN lines. >The option of an external TA (such as a Motorola BitSRFR) is very apealing, >but behavior at these speeds needs careful consideration. > >How would you adjust the drivers to acomodate these speeds? 115200 was fast 10 years ago, but 230400 is currently not well support (if you change the hardware clock to get it, then then the buffer sizes are too small). How many ports do you need? >We experienced a lot of complex problems with SCSI transactions until we >bumped the sio interrupt bufferto double its size. While performance (on >the sio ports - we use them only for PPP) did not drop visibly, the strange >incidence of dropping biodone() calls virtually stopped. This probably just made a race less common. Bruce
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199706291005.UAA29898>