DPC queuing and delivery

There is a great article on OSR regarding DPC queuing and delivery, it answers questions like when DPCs are being queued, whether the software interrupt will be issued. and when the DPCs are being delivered, which thread context it will run at.

http://www.osronline.com/article.cfm?article=529

Bonus reading: the article also mentioned another article on OSR about several useful debugging techniques: http://www.osronline.com/article.cfm?article=522