Hello,

I have noticed a very great difference comparing the performance of user
and kernel mode drivers for CE 4.2.

When a driver runs in user mode and I call a driver service from my
application using DeviceIoControl it takes about 40 microsec. The service
does not perform any operation and returns immediately.
If I compile the driver as a kernel mode driver and load it with
LoadIntChainHandler a call from my application of the same driver service
with KernelLibIoControl takes only 1 microsec. I am using XScale 400 MHz
CPU with Win CE 4.2.
Is this behaviour intended or do I make anything wrong?

Thanks in advance

Max

Are you sure you checked the same direction , because KernelLibIoControl()
use to talk to interrupt handler from driver and not from user mode to
driver.
Any case ask additionally on
microsoft.public.windowsce.platbuilder
Arkady

"max" <max@discussions.microsoft.com> wrote in message
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