On Thu, Jun 07, 2018 at 05:54:56PM +0000, Max Asbock wrote: > > ________________________________________ > 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. Ugh, I forgot about the workqueue rewrite. How about 4.14, does that work for you? If so, just use that, you shouldn't be using the 4.9 kernel tree on x86-based hardware unless you are somehow forced to due to horrible closed source kernel drivers. You want and need the fixes and speedups that are on 4.14.y, it's a measurable difference. thanks, greg k-h
