Performance change from X in Fedora Core 4 to Fedora Core 5

Clemens Eisserer linuxhippy at
Wed Jul 12 23:01:51 PDT 2006

> it is give and take. you incur some extra expense for a temporary pixmap
> allocation and de-allocation in return for not holding on to that video ram
> permanently and thus eventually running out of video ram and needing to swap
It seems as we don't get ahead anymore.

Keeping in mind that the extra pixmap most likely will be used only
extensivly in short timeframes (user is activly using the gui,
expose-events because another window is moved in front, ....) and that
in this short timeframes the goal is to archive highest performance I
think there must be better ways than allocation and deallocation every

I don't see a problem with memory useage, almost all graphic-cards
have more than 16mb which is more than enough.
Furthermore implement almost all drivers I know about quite clever
swaping algorytmns and who cares about a pixmap in RAM which isn't
used frequently anyway...

I think a lot vram can be saved if you take a bit care about how long
holding the pixmap:

Solution 1: only hold it when the window is visible or in a state
where a expose could happen.
Solution 2: Solution 1 + some algorytmns which free the pixmap after
it has not been used for xy seconds.
Solution 3: Your idea ;-)

lg Clemens

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