Basic System Problem Analysis - August 2003

Case Study: Hang Memory Dump continued

At this point we know that Pin 86 was blocked on a semaphore owned by Pin 35. We

want to go look at what Pin 35 is doing and we find that this process has called DBLOCK

and is also blocked. Note that it also has “SEM_BLOCK” in its stack trace. You only see

this when a process blocks on a semaphore.

We need to see what semaphore this process is waiting on.

In terms of red flags, this is a great big banner sized flag, a process owning a semaphore

is also blocked on one! Not a good sign at all.