Framebuffer console performance

I have a non-standard framebuffer (i.e. I wrote the driver,
based on the au1000 driver) running on 2.4.27.  When I run
virtual consoles on it, I see sluggish scroll performance.
I get quite acceptable performance when the system first
comes up, e.g. during the system initialization messages,
but not long afterwards the scrolling slows down.  It can
get continually worse, eventually ending up at a crawl.

This is a memory limited embedded system, but I do not
have any swapping going on.

Ideas or hints where I might look?

Thanks for your time.

n.b. I'm not subscribed to this list, so please CC my direct
email address when replying.

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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On Friday 25 March 2005 06:14, Gary Thomas wrote:

I have a non-standard framebuffer (i.e. I wrote the driver,
based on the au1000 driver) running on 2.4.27.  When I run
virtual consoles on it, I see sluggish scroll performance.
I get quite acceptable performance when the system first
comes up, e.g. during the system initialization messages,
but not long afterwards the scrolling slows down.  It can
get continually worse, eventually ending up at a crawl.

When the system starts up, the scroll mode is 'redraw'.  This mode is
acceptable, not too slow and not too fast either, whatever the hardware is.

After starting up, the scroll mode changes depending on the driver.  Most
probably, it is using ypan which is not too great on systems without
accelerated rectangle moves and framebuffer reads are slow.

Try setting vyres == yres using fbset and see if that helps.

Tony




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