Messages in this thread | | | Date | Wed, 9 Dec 2020 05:51:37 +0900 | From | Sergey Senozhatsky <> | Subject | Re: consoles: was: [PATCH next v2 3/3] printk: remove logbuf_lock, add syslog_lock |
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On (20/12/07 10:50), Petr Mladek wrote: [..] > > and then some call into the scheduler > > (or other kernel core functions) under semaphore's spin_lock. > > For instance > > > > up() > > raw_spin_lock_irqsave(&sem->lock) > > __up() > > wake_up_process() > > try_to_wake_up() > > This problem is partly solved by printk_deferred(). In each > case, printk_safe() does not help here.
printk_deferred() has never been used in all the critical code paths. So I think printk_safe does help here; it takes care of all the remaining cases, that are not "partly solved by printk_deferred()".
> I still do _not_ see a reason to keep printk_safe()!
Not sure I'm following, sorry. To put it simply - we better keep printk_safe until "new recursion prevention" >= printk_safe(). In this patch set "new recursion prevention" < printk_safe().
-ss
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