Re: The motivation of adding fallback_counter to exa

2010-10-14 Thread Adam Jackson
On Thu, 2010-10-14 at 13:46 +0800, fly fancy wrote:
 Thanks a lot! I would agree with your explanations. However, I have
 another confusion.
 In mixed pixmap mode, when the arguments 'w' and 'h' passed to
 exaCreatePixmap_mixed is either zero, 
 this pixmap will become a driver pixmap through
 exaCreateDriverPixmap_mixed right away. Usually, 
 in this situation, the exaModifyPixmapHeader_mixed should be called
 with non-null pPixData. But,  
 exaModifyPixmapHeader_mixed will delete pixmap driver private when
 pPixData is non-null and set 
 this pixmap pinned. Therefore, I think this(create pixmap driver
 private, then destroy it without using it) is 
 meaningless. Do I understand it wrong? Thanks!

That sounds like extra work, but it sounds harmless, so I think you
understand it right.

- ajax


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Re: The motivation of adding fallback_counter to exa

2010-10-12 Thread Adam Jackson
On Tue, 2010-10-12 at 11:34 +0800, fly fancy wrote:
 Hello, all
 In newer XServer edition, the fallback_counter is
 introduced to EXA. However, I almost can not understand the motivation
 of the fallback_counter mechanism. Anyone understand it? I'll be very
 appreciated for your explanation. Thanks !

Near as I can tell (the commit message isn't great), it's like this:

Sometimes, you're doing a software fallback, and to do that fallback you
need to draw into a scratch pixmap and then scrape the bits out of it
and put them into the real destination.  Any scratch pixmap so created
should itself be rendered entirely in software in host memory, since
otherwise you'll be reading bits back out of the framebuffer and that's
_super_ slow.

So once the fallback count is non-zero, force everything to the host
memory path; and then allow it to be an integer so recursive fallbacks
work (which is pathological, but I guess it could happen).

- ajax


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The motivation of adding fallback_counter to exa

2010-10-11 Thread fly fancy
Hello, all
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Re: The motivation of adding fallback_counter to exa

2010-10-11 Thread fly fancy
Hello, all
In newer XServer edition, the fallback_counter is introduced to
EXA. However, I almost can not understand the motivation of the
fallback_counter mechanism. Anyone understand it? I'll be very appreciated
for your explanation. Thanks !

Best wishes



2010/10/12 fly fancy fancyfl...@gmail.com

 Hello, all


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