Messages in this thread | | | Date | Wed, 15 Jun 2022 22:09:17 +0200 | From | Petr Mladek <> | Subject | Re: [PATCH 0/2] printk: Prevent printk kthreads from blocking direct console handling |
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On Wed 2022-06-15 10:10:42, Paul E. McKenney wrote: > On Wed, Jun 15, 2022 at 06:28:03PM +0200, Petr Mladek wrote: > > There are reports that console kthreads prevented printing > > messages during panic() or shutdown(), see > > BugLink: https://lore.kernel.org/r/20220610205038.GA3050413@paulmck-ThinkPad-P17-Gen-1 > > BugLink: https://lore.kernel.org/r/CAMdYzYpF4FNTBPZsEFeWRuEwSies36QM_As8osPWZSr2q-viEA@mail.gmail.com > > > > In both situations, printk() correctly tries to flush the consoles > > directly but it fails to get the global console_lock(). Both > > problems went away with these patches: > > > > 1st patch blocks console kthreads so that they do not start > > handling new messages when the direct printing is preferred > > by the system state. It is probably enough on its own. It > > solves the problem when the kthreads actively did > > the wrong thing. > > > > 2nd patch allows to wait for the console kthreads to release > > the lock in any context. It should make it more reliable. > > It would have been useful even for the legacy code. > > Thank you! > > For the series: > > Tested-by: Paul E. McKenney <paulmck@kernel.org>
Thanks a lot for testing.
I have pushed it into printk/linux.git, branch rework/kthreads to give it a spin in linux-next.
Best Regards, Petr
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