[Libdlo] [RFC 2.6.30 1/1] defio fbdev displaylink implementation

Florian Echtler floe at butterbrot.org
Fri Oct 9 03:26:04 PDT 2009

Hello Phil,

>> One interesting area of performance concern for Jaya's driver (once
>> compression is added) is the 4KB granularity of defio - sending any
>> unnecessary pixels over USB will hasten our most important bottleneck.
> In my experience of similar problems in other domains, you have two cases:
> - Small changes, where the 4k block size is inefficient; in this case
> it doesn't really matter that it's inefficient, because the changes are
> small anyway.
Does this still apply to cases like cursor movement which are small, but 
come in large numbers?

I'm admittedly not up to date anymore regarding the current state of 
in-kernel development. AFAICT the OpenBSD driver by Marcus Glocker already 
has compression support; has discussion now shifted to the 
linux-fbdev-devel list?

Yours, Florian
"_Nothing_ brightens up my morning. Coffee simply provides a shade of
grey just above the pitch-black of the infinite depths of the _abyss_."

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