Re: XP increased processor utilization

I am working on a multi-threaded, statically linked MFC (VC++ 6.0)
application. It is an MDI app with multiple views, many of which are layered
on top of one another and are shown or hidden based on button pushes. The
problem I'm running into is two fold. The first is that in general running
the same application under Windows XP SP2 uses more processing power than
when running under Windows 2K SP4(about 8% or so more). The other issue
which is the real problem is that movement of the mouse across any part of
the application results in an increase of CPU utilization (according to Task
Manager & Perfmon) that is significantly higher under XP. Under 2K, similar
movement of the mouse results in a 1-3% increase of processor utilization.
Under XP, the processor utilization jumps 10-25%.

I'm fairly confident that the problem is not in the background logic but
lies somewhere within the user interface part of the app because the
offending thread is the 0-th thread which is the Windows MFC framework
thread.

I've tried dumbing down the interface by commenting out the creation of many
of the document views. If I reduce the interface to a single view, I don't
appear to have any problems. I then started adding individual views back in,
all of which are "behind" the original view. There aren't any specific
message handlers for these views and when debugging, it doesn't appear any
methods of the hidden views are being called during mouse movement.
Eventually after adding enough views (~5), the processor utilization goes
from a 3% increase on mouse movement to a 9% increase. It doesn't matter
which view I add back in either.

    Running the same application with all views created in Win2K does not
result in much more than a 3% increase. I'm stumpped at this point and
wondering if anyone has seen this or knows if this could be related to MFC,
Win32, or potentially something else.

Shaun