Re: [Crash-utility] Running idle threads show wrong CPU numbers
----- "Michael Holzheu" <holzheu(a)linux.vnet.ibm.com> wrote:
Hi again,
> When I change get_smp_cpus() to return
"get_highest_cpu_online() + 1" I
> see five swapper idle tasks when using "ps". The problem I now have is
> that I have to provide a backtrace for the offline cpus. But the offline
> CPUs do not have any stack on s390. Is there a way to tell crash that
> there is no backtrace available? Probably I overlooked something...
Ok, I think I got it now. In case of an offline CPU, I will use
"task_struct_thread_ksp" like I do it for non active tasks.
When I do that I get for the swapper tasks with the offline CPUs:
PID: 0 TASK: 18d38340 CPU: 2 COMMAND: "swapper"
#0 [18d3feb8] ret_from_fork at 117e12
PID: 0 TASK: 18d40440 CPU: 3 COMMAND: "swapper"
#0 [18d47eb8] ret_from_fork at 117e12
I'm not why you should do anything. The cpu is offline and for all
practical purposes it doesn't exist, so why bother?
The patch I have queued just uses get_highest_cpu_online()+1 and
does nothing else. But I only tested it on a live system, and
any backtrace attempt on the offlined swapper task just shows
(active). What happens when you do a "bt -a" with a dumpfile?
Dave