Re: [GIT pull] CPU hotplug updates for 4.9

[Thomas Gleixner <tglx@linutronix.de>]

On Tue, 7 Mar 2017, Bart Van Assche wrote:
> On Mon, 2016-10-03 at 19:37 +0200, Thomas Gleixner wrote:
> > Yet another batch of cpu hotplug core updates and conversions:
> 
> Hello Thomas,
> 
> Although I'm not sure this behavior has been introduced by the changes in this
> pull request, since I started testing v4.11-rc[01] I ran several times into a
> cpuhp_issue_call() hang:

...

> INFO: task systemd-udevd:837 blocked for more than 480 seconds.
>       Tainted: G          I     4.11.0-rc1-dbg+ #1
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> systemd-udevd   D    0   837    542 0x00000104
> Call Trace:
>  __schedule+0x302/0xc30
>  schedule+0x38/0x90
>  schedule_timeout+0x255/0x490
>  wait_for_completion+0x103/0x170
>  cpuhp_issue_call+0xb9/0xe0
>  __cpuhp_setup_state+0xf6/0x180
>  pkg_temp_thermal_init+0x76/0x1000 [x86_pkg_temp_thermal]
>  do_one_initcall+0x3e/0x170
>  do_init_module+0x5a/0x1ed
>  load_module+0x2339/0x2a40
>  SYSC_finit_module+0xbc/0xf0
>  SyS_finit_module+0x9/0x10
>  do_syscall_64+0x57/0x140
>  entry_SYSCALL64_slow_path+0x25/0x25
> 
> Kernel v4.10 runs fine on the same system. From the dmidecode output:

That's odd. There was no change related to the hotplug stuff post 4.10
neither in the core nor in that particular driver.

I have no immediate clue what to look for aside of asking you whether you
could do a bisect between 4.10 and 4.11-rc1.

Thanks,

	tglx