Re: [PATCH] printk: modify console_unlock with printk-safe macros

From: Sergey Senozhatsky
Date: Mon Jul 17 2017 - 05:28:23 EST


On (07/15/17 18:36), Pierre Kuo wrote:
[..]
> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> index fc47863..21557cc 100644
> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -2194,8 +2194,7 @@ void console_unlock(void)
> size_t ext_len = 0;
> size_t len;
>
> - printk_safe_enter_irqsave(flags);
> - raw_spin_lock(&logbuf_lock);
> + logbuf_lock_irqsave(flags);
> if (seen_seq != log_next_seq) {
> wake_klogd = true;
> seen_seq = log_next_seq;
> @@ -2267,8 +2266,7 @@ void console_unlock(void)
> */
> raw_spin_lock(&logbuf_lock);
> retry = console_seq != log_next_seq;
> - raw_spin_unlock(&logbuf_lock);
> - printk_safe_exit_irqrestore(flags);
> + logbuf_unlock_irqrestore(flags);
>
> if (retry && console_trylock())
> goto again;

I did it that particular way for a reason - console_unlock() does a
bunch of tricks: unlocking logbuf in the middle of printing loop,
breaking out of loop with local IRQs disabled, re-taking the logbuf
after the loop still will local IRQs disabled, etc. etc. I didn't
want to (and still don't) mix-in logbuf macros; we do things that
macros don't cover anyway. sorry, I don't agree that the patch
improves readability.

-ss