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From: Greg KH [greg@xxxxxxxxx]
Sent: Thursday, June 07, 2018 1:37 AM
To: Max Asbock
Cc: stable@xxxxxxxxxxxxxxx; tytso@xxxxxxx; Chris McDermott
Subject: [External] Re: panic at boot time with kernel >= 4.9.98 - uninitialized system_wq in early interrupt
> Ick :(
> I'm guessing you also see these problems on 4.17? Can you test there to
> be sure of that?
We haven't had a chance to test 4.17 on the system where this happens. I am suspecting this won't be a problem on 4.17 as workqueue init has been split up and there is now a workqueue_init_early() in start_kernel():
/*
* Allow workqueue creation and work item queueing/cancelling
* early. Work item execution depends on kthreads and starts after
* workqueue_init().
*/
workqueue_init_early();
So far we have only seen this with 4.9.x. Also, this only happens when lots of memory is installed (10TB). i am guessing the large memory size changes the timing of the initialization steps and brings out the problem.
When we get access to the system again we can attempt to boot the latest main-line kernel to verify that the work_init_early indeed fixes the issue there.
Max
