1.4 -> 1.5.1 performance regressions

[Fabio]

> On Tue, 2009-01-27 at 12:42 +0100, Fabio wrote:
> > > On Tue, 2009-01-27 at 11:55 +0100, Fabio wrote:
> > > > > On Thu, 2008-10-09 at 11:02 +0200, Fabio wrote:
> > > > > > 
> > > > > > I noticed some performance regression moving to a newer system with Xserver
> > > > > > 1.5.1 from an 1.4 system with both XAA and EXA.
> > > > > 
> > > > > Can you try current Git server-1.5-branch? Adam Jackson just backported
> > > > > the reduction of dixLookupPrivate() overhead, which is used extensively
> > > > > by the EXA core at least. If there are still regressions with EXA, I'd
> > > > > be interested in sysprof/oprofile data separately for each regressed
> > > > > case.
> > > > 
> > > > I noticed that pre-1.6 is faster than 1.5.3, but still slower than 1.4.
> > > > 
> > > > As reported by someone in the bug report, the patch from
> > > > https://bugs.freedesktop.org/show_bug.cgi?id=16647#c11 was never
> > > > applied. Is it still needed?
> > > 
> > > Have you tried it to see if it helps for the performance regressions you
> > > noticed?
> > 
> > No (I am using prebuilt packages), however, according to this comment, it fixes the regression:
> > https://bugs.freedesktop.org/show_bug.cgi?id=16647#c14
> 
> ... for the benchmark / workloads discussed in the bug report. Are the
> workloads you noticed the performance regression with similar to those?

I am getting these results with gtkperf, compared to what I got with
1.4. Note, however, that not all performance differences could be due
to the X server, since I upgraded all system during that time (the 
radeon driver however is almost the same):

+ -> faster
- -> slower
= -> about the same
                                  1.4     1.5.99.901  Difference
GtkEntry                 - time:  0,09    0,09        =
GtkComboBox              - time:  3,83    5,74        -
GtkComboBoxEntry         - time:  2,96    4,53        -
GtkSpinButton            - time:  0,51    0,53        =
GtkProgressBar           - time:  0,27    0,24        =
GtkToggleButton          - time:  1,34    0,50        +
GtkCheckButton           - time:  1,44    0,28        +
GtkRadioButton           - time:  1,79    0,77        +
GtkTextView - Add text   - time: 11,68   11,96        =
GtkTextView - Scroll     - time:  2,84    2,22        +
GtkDrawingArea - Lines   - time:  2,43    4,90        -
GtkDrawingArea - Circles - time:  1,86    3,77        -
GtkDrawingArea - Text    - time:  3,89    3,42        +
GtkDrawingArea - Pixbufs - time:  0,30    0,36        -
 ---
Total                    - time: 35,22   39,33        -

See also https://bugs.freedesktop.org/show_bug.cgi?id=16647#c24