Re: slow screen updates on laptop console (i386)

From: Alexander Kabaev <kabaev_at_gmail.com>
Date: Mon, 7 Dec 2015 09:18:15 -0500
On Mon, 7 Dec 2015 09:02:35 -0500 (EST)
Rick Macklem <rmacklem_at_uoguelph.ca> wrote:

> Hi,
> 
> When running FreeBSD-current on an old i386 laptop, the console
> screen is intermittently slow to display output. The hesitations
> can be several seconds.
> Sometimes it shows up when I'm typing such that it takes seconds
> for the characters to echo.
> I think it is the display/output side, since I've seen it happen when
> doing "more <file>", where the screen is stuck half way through
> displaying the page for a few seconds.
> 
> I don't see any problem when going into the machine remotely and
> I don't see the problem on the other laptop I have running
> FreeBSD/amd64.
> 
> It has been happening for a while. It occurs on the oldest kernel
> I have lying around (r287930, Sep. 17, 2015).
> 
> I've tried the old "sc" driver and it seems to happen less with it,
> but it still occurs.
> 
> I'll admit I have no idea what drives doing output for the display
> screen.
> 
> Anyone have ideas w.r.t. this?
> 
> Thanks in advance, rick

Hi,

maybe a stretch, but I would try selecting different eventtimer, if
available. Say, I had to select HPET on my old i7 920 to make timeouts
run reliably.

sysctl kern.eventtimer.timer=HPET
 
-- 
Alexander Kabaev

Received on Mon Dec 07 2015 - 13:18:22 UTC

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