Subject: Re: tty output problems
To: Port-i386 <port-i386@NetBSD.ORG>
From: Jukka Marin <jmarin@pyy.jmp.fi>
List: port-i386
Date: 05/21/2000 18:33:22
On Sun, May 21, 2000 at 01:22:43PM +0300, Jukka Marin wrote:
> NetBSD 1.4.2, i386:
> 
> I'm running a simple serial protocol between a NetBSD box a some custom
> hardware.  The problem is that every now and then (especially when the
> NetBSD box is doing something CPU intensive) I get protocol timeouts on
> the remote device.  It seems that NetBSD does not fill the UART transmit
> FIFO fast enough, so the data flow is interrupted and the remote device
> times out.

Another thing comes to mind:  When I was running something like 1.3F, I
couldn't cause mpg123 sound to pause even when running gcc etc. on the
same system.  Now that I'm running 1.4.2, mpg123 output pauses every now
and then when I stress the system.  I'm using a 2 MB buffer and the
pauses happen at the moment when I stress the machine, so it can't be
the 2 MB buffer running out of data, but the system feeding data from the
buffer to the audio system (or from the audio device buffer to hardware).

Could this be related to some kind of a scheduler change?  Maybe processes
requiring tiny slices of CPU at short intervals aren't getting the attention
they used to get?  This would explain both my serial port problem and the
mpg123 problem.

  -jm