[PATCH 3/3] exa/mixed: Exclude frontbuffer from deferred pixmap handling.

[Michel Dänzer]

On Mon, 2010-12-13 at 19:42 +0100, Maarten Maathuis wrote: 
> - Apps like xterm can trigger a lot of fallback rendering.
> - This can lead to (annoyingly) high latencies, because you
>   have to wait for the block handler.
> - You need a driver that doesn't directly access the front
>   buffer to trigger this (NV50+ nouveau for example).
> - Repeatingly doing dmesg on an xterm with a bitmap font
>   will reveal that you never see part of the text.
> - I have recieved at least one complaint in the past of slow
>   terminal performance, which was related to core font
>   rendering.
> - This does sacrifice some throughput, not sure how much,

Shouldn't be hard to measure.

> but users tend to respond poorly to unexpected latency IMO.

I'm sure some do, but I also suspect some do to unexpected slowness. :}


-- 
Earthling Michel Dänzer           |                http://www.vmware.com
Libre software enthusiast         |          Debian, X and DRI developer