On (20/04/23 22:28), Tetsuo Handa wrote:
[..]
> +/* Annotation for "don't print to consoles". */
> +#define KERN_NO_CONSOLES KERN_SOH "S"
> +
> /* integer equivalents of KERN_<LEVEL> */
> #define LOGLEVEL_SCHED -2 /* Deferred messages from sched code
> * are set to this special level */
> diff --git a/include/linux/printk.h b/include/linux/printk.h
> index e061635e0409..da338b81c2e1 100644
> --- a/include/linux/printk.h
> +++ b/include/linux/printk.h
> @@ -19,6 +19,7 @@ static inline int printk_get_level(const char *buffer)
> switch (buffer[1]) {
> case '0' ... '7':
> case 'c': /* KERN_CONT */
> + case 'S': /* KERN_NO_CONSOLES */
> return buffer[1];
> }
> }
> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> index 9a9b6156270b..ed51641af087 100644
> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -361,6 +361,7 @@ static int console_msg_format = MSG_FORMAT_DEFAULT;
> */
>
> enum log_flags {
> + LOG_NO_CONSOLES = 1, /* don't print to consoles */
> LOG_NEWLINE = 2, /* text ended with a newline */
> LOG_CONT = 8, /* text is a fragment of a continuation line */
> };
> @@ -1959,6 +1960,9 @@ int vprintk_store(int facility, int level,
> break;
> case 'c': /* KERN_CONT */
> lflags |= LOG_CONT;
> + break;
> + case 'S': /* KERN_NO_CONSOLES */
> + lflags |= LOG_NO_CONSOLES;
> }
[..]
Hmm. Any chance that those NO_CONSOLE messages overflow logbuf so then
we start losing pending YES_CONSOLE messages?
-ss
