linux-kernel - Re: linux.git: printk() problem

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Date:   Mon, 24 Oct 2016 23:08:45 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky@...il.com>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Joe Perches <joe@...ches.com>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        Petr Mladek <pmladek@...e.cz>,
        Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
Subject: Re: linux.git: printk() problem

Hello,

thanks for Cc-ing.

On (10/23/16 12:46), Linus Torvalds wrote:
> +static void deferred_cont_flush(void)
> +{
> +	static DEFINE_TIMER(timer, flush_timer, 0, 0);
> +
> +	if (!cont.len)
>  		return;
> +	mod_timer(&timer, jiffies + HZ/10);
>  }

[..]

> @@ -2360,6 +2285,8 @@ void console_unlock(void)
>  		return;
>  	}
>  
> +	deferred_cont_flush();
> +

is mod_timer() safe enough to rely on/call from
	panic()->console_flush_on_panic()->console_unlock() ?

shouldn't deferred_cont_flush() be called every time we jump
to `again' label in console_unlock()?

timer has debug object support, which probably can printk(), but
that shouldn't cause any troubles, I suppose.

	-ss