153456 - RealizePalette causes performance problems

Status: RESOLVED FIXED

(Core Graveyard :: GFX, defect, P1)

Description

[Kevin McCluskey (gone)]

The RealizePalette call in nsRenderingContextWin::CopyOffScreenBits is expensive
and it does not seem to be necessary. It causes performance issues for some
Gecko based applications running in 8-bit display mode.

Comment 1

[dcone (gone)]

Attachment: Patch to take out the realizepalette from the bitblit copy

If you apply this patch (taking out the RealizePalette() call in the
CopyOffScreenBits seems we play nicer with embedded applications.  Seems that
RealizePalette is called everytime the copy from the offscreen buffer goes to
the front which is expensive..
and can timeout the embedded aplications. The RealizePalette() is called
alreadywhen the nsRenderingContext is constructed and when the pixels are
locked.  I just commented out the one call to RealizePalette until I can
completly fix
this correctly. I opended a bug (#153367) for fixing the palettes once and for
all and commented in the source.  I am trying to make this as small a risk as
possible.  I tested with my build for a day using 256 colors and playing with
apps that mess with the palette.  I also have a utility that looks at the
system palette while I did that.  No new bugs appeared.. although I did notice
some bugs that were already there.  My point is that nothing got worse. 
Performance did improve.

Comment 2

[Kevin McCluskey (gone)]

Comment on attachment 88696 [details] [diff] [review]
Patch to take out the realizepalette from the bitblit copy

r=[e-mail]

Comment 3

[Chris Waterson]

Comment on attachment 88696 [details] [diff] [review]
Patch to take out the realizepalette from the bitblit copy

sr=waterson

Comment 4

[dcone (gone)]

fixed

Comment 5

[Chak Nanga]

We need to get this onto the Mozilla 1.01 branch as well.

Don : Can you please send a note to ADT/Drivers for branch checkin approval..thanks

Comment 6

[Judson Valeski]

please checkin to the 1.0.1 branch. once there, remove the "mozilla1.0.1+"
keyword and add the "fixed1.0.1" keyword.

Comment 7

[scottputterman]

adding adt1.0.1+.  Please check into the branch asap.

Comment 8

[Chak Nanga]

Patch checked in to the 1.01 branch (by Dcone)

Comment 9

[Chris Petersen]

Not sure how QA can verify this one. Need to put verified1.0.1 in keyword field
when verified on branch.