Profiling redraws with Xorg

Peter Clifton pcjc2 at
Fri Dec 26 07:46:00 PST 2008

Hi guys,

I've been profiling some speed differences rendering pixel aligned
(should be fast-path) cairo drawing, and happened across the fact that
for my redraw test (which is running flat out), 13% of my total system
time is spent in dixLookupPrivate.

Is there anything which can be done to avoid the overhead of

The overhead is spread over a number of callers, the top few being:

exaPixmapIsOffscreen (Total 3.43%)
exaDoMoveInPixmap    (Total 1.82%)
exaDoMigration       (Total 1.17%)

Now whether this is simply because my cairo rendering is slow, and
causing lots of migration I don't know.. but I thought it would be of
interest here.

This is made with the Intel driver at the tip of the 1.6 branch, using
EXA acceleration.

Best wishes,

Peter Clifton

Electrical Engineering Division,
Engineering Department,
University of Cambridge,
9, JJ Thomson Avenue,

Tel: +44 (0)7729 980173 - (No signal in the lab!)

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