Colleagues,

Over the past few years I've been heavily involved in two projects that 
deal with PCI HotPlug.  While doing this work, one area of code always 
seems to require printk's to debug through -- the allocation & freeing 
of IO & MEM resources.

I've discovered many bugs surrounding Hotplug PCI IO & MEM allocations 
that would have been much easier to debug had there been printk's 
existing within the code, including one recently which impacts all of 
PCI Hotplug and appears to have been around since pre-2.6.9 (a patch to 
fix this issue has already been reviewed & accepted by Greg Kroah). 

As Hotplug continues to mature and more Hotplug drivers are introduced, 
I suspect that more and more bugs will be introduced in the resource space.

I propose the following patch to add a compile time DEBUG option to 
kernel/resource.c that would help in analyzing problems in this area.  
It's a few simple lines of output in  __request_resource, 
__release_resource, __request_region, and __release_region .

Thanks,

P.