Messages in this thread | | | Date | Tue, 11 Sep 2018 11:30:39 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH 4.19 regression fix] printk: For early boot messages check loglevel when flushing the buffer |
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On (09/10/18 16:57), Petr Mladek wrote: > > Good catch. > > > --- > > > > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > > index c036f128cdc3..ede29a7ba6db 100644 > > --- a/kernel/printk/printk.c > > +++ b/kernel/printk/printk.c > > @@ -2545,6 +2545,7 @@ void console_flush_on_panic(void) > > * ensure may_schedule is cleared. > > */ > > console_trylock(); > > + exclusive_console = NULL; > > This is not be enough. It would cause replying old messages > on all consoles.
Oh, that was intentional. I consider repeated messages to be less problematic than the missing ones.
> Most problems should probably be solved when we store console_seq > before setting exclusive_console. Then we could clear > exclusive_console when reaching the stored sequence number. > > Can this be that simple? ;-)
This can work, yes.
I also thought about doing it the way Linus, Jan Kara and Hannes Reinecke proposed:
- store the console_seq nr of the first oops_in_progress message (oops_console_seq) and flush only messages that are in [oops_console_seq - 200, log_next_seq] range, as opposed to complete logbuf flush.
Hannes asked for this several times. And it was in Jan's printk patches long time ago (if I'm not mistaken - sorry if I am -- Jan said that Linus wanted that "just N messages prior to oops" thing).
Jan's patch: https://lore.kernel.org/lkml/1457964820-4642-3-git-send-email-sergey.senozhatsky@gmail.com/T/#u
> This reverts commit 375899cddcbb26881b03cb3fbdcfd600e4e67f4a. > > Reported-by: Hans de Goede <hdegoede@redhat.com> > Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
-ss
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