Explore the challenges and potential solutions for unblocking the softirq lock in PREEMPT_RT systems in this 31-minute conference talk from the Linux Plumbers Conference. Delve into the complexities of bottom halves functioning as a per-CPU Big Kernel Lock and how this affects data structure locking. Examine the impact on networking performance, where packet sending can be delayed due to receiving processes, even when preempted by higher priority tasks. Join the discussion with the networking community, the primary softirq users, to brainstorm strategies for avoiding this big lock and improving system responsiveness in real-time environments.