Lightfleet interview questions

I was contacted by Systems Pros who found my LinkedIn profile. The recruiter provided a job description, and I was interested, so I sent a customized cover letter and a copy of my resume. I then spoke with the recruiter over the phone and answered some of the prepared questions from their client. They were fairly basic. Do I have any patches in mainline Linux? Have I used Mutexes and Spinlocks? Have I ever had a job working on Linux drivers before? Since I passed the basic questions, the recruiter setup a phone interview with the lead software developer. The interviewer was quite friendly and he told me about their product and what they are building (high speed switches, and a network card). Then he asked me to introduce myself. And after that we went straight in to the technical questions. The questions weren't hard but you either know them or you don't. There were several that I didn't know, and as a result, after about 10 minutes, he had already decided that I wasn't a perfect fit.