Subject: Re: More on rcons performance woes: pmax profiling
To: Chris G. Demetriou <>
From: Jason Thorpe <>
List: tech-kern
Date: 03/02/1999 11:44:51
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 <>