Subject: Re: More on rcons performance woes: pmax profiling
To: Jason Thorpe <>
From: R. C. Dowdeswell <>
List: tech-kern
Date: 03/02/1999 13:28:36
On 920403891 seconds since the Beginning of the UNIX epoch
Jason Thorpe wrote:
>On 02 Mar 1999 10:17:11 -0800 
> (Chris G. Demetriou) wrote:
> > The 'sun' emulator at least implements the Sun console 'normal' way of
> > picking how much to scroll at a time, ESC[<n>r (known in the Sun
> > manual pages as SUNSCRL; btw, in case anybody's watching, the name
> > wscons and the fact that it's apparently the same as the sun console
> > driver name was unintentional, or at least, not a conscious decision
> > 8-).
>It might be interesting to defer scroll operations, and wait for more
>scrolls to happen, up to some threshold... sort of like Nagle for the
>console :-)
>The algorithm could be something like checking for pending copyrows
>operations every T ticks, and processing them in a single multi-text-line
>blit.  If you get more than N copyrows requests before the interval expires,
>process them early (so you don't have to store too much state).
>        -- Jason R. Thorpe <>

This is actually what I was thinking would be a good idea, I believe
that this is more or less what an xterm does.  I remember being
annoyed by sun's scrolling back in the days of SunOS 4.1.3.  Having
the screen scroll up ten lines just because a single line has been
output is suboptimal, IMO.

 == Roland Dowdeswell