Re: [Crash-utility] crash aborts with cannot determine idle task

Look at the crash function get_idle_threads() in task.c, which is where you're failing. It runs through the history of the symbols that Linux has used over the years for the run queues. For the most recent kernels, it looks for the "per_cpu__runqueues" symbol. At least on 2.6.25-rc2, the kernel still defines them in kernel/sched.c like this: static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); So if you do an "nm -Bn vmlinux | grep runqueues", you should see: # nm -Bn vmlinux-2.6.25-rc1-ext4-1 | grep runqueues ffffffff8082b700 d per_cpu__runqueues # I'm guessing that's not the problem -- so presuming that the symbol *does* exist, find out why it's failing to increment "cnt" in this part of get_idle_threads(): if (symbol_exists("per_cpu__runqueues") && VALID_MEMBER(runqueue_idle)) { runqbuf = GETBUF(SIZE(runqueue)); for (i = 0; i < nr_cpus; i++) { if ((kt->flags & SMP) && (kt->flags & PER_CPU_OFF)) { runq = symbol_value("per_cpu__runqueues") + kt->__per_cpu_offset[i]; } else runq = symbol_value("per_cpu__runqueues"); readmem(runq, KVADDR, runqbuf, SIZE(runqueue), "runqueues entry (per_cpu)", FAULT_ON_ERROR); tasklist[i] = ULONG(runqbuf + OFFSET(runqueue_idle)); if (IS_KVADDR(tasklist[i])) cnt++; } } Determine whether it even makes it to the inner for loop, whether the pre-determined nr_cpus value makes sense, whether the SMP flag reflects whether the kernel was compiled for SMP, whether the PER_CPU_OFF flag was set, what address was calculated, etc... Dave