Messages in this thread | | | Date | Thu, 17 Jun 2021 13:23:20 +0200 | From | Petr Mladek <> | Subject | Re: [PATCH next v4 0/2] introduce printk cpu lock |
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On Thu 2021-06-17 11:56:49, John Ogness wrote: > Hello, > > While working on removing the safe buffers for printk [0] we > stumbled on a cpu-reentrant spinning lock used by dump_stack(). This > type of lock (dubbed a cpu lock) will cause deadlock risks once we > introduce atomic consoles because atomic consoles also need such a > lock. > > Although we are not yet ready to introduce atomic consoles, this is > an appropriate time to provide an official cpu lock to be used for > all things relating to printk (including the atomic consoles, once > they are introduced). > > An example of cpu lock usage for atomic consoles can be found in the > PREEMPT_RT tree, such as the serial8250 implementation [1] of an > atomic console. (In PREEMPT_RT the printk cpu lock function was > named console_atomic_lock/_unlock.) > > This series is against next-20210616. > > John Ogness (2): > lib/dump_stack: move cpu lock to printk.c > printk: fix cpu lock ordering
For both patches:
Reviewed-by: Petr Mladek <pmladek@suse.com>
The patchset is ready for linux-next from my POV. We are getting close to the merge window so I am going to push it tomorrow. We could always remove it when anyone has comments the following week.
Best Regards, Petr
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