Re: [PATCH -mm] PM: Remove sleeping from suspend_console

[Stefan Seyfried <seife@suse.de>]

On Mon, Sep 04, 2006 at 10:50:40PM +0200, Rafael J. Wysocki wrote:
> Remove ssleep() from suspend_console().
> 
> Stefan thinks it is unnecessary and will slow down the suspend too much.

"unnecessary" is not exactly what i think, rather "unacceptable" :-)
We probably need to do something for some kinds of consoles to make sure all
characters are sent, but sleeping unconditionally is not the right thing IMO.

> --- linux-2.6.18-rc5-mm1.orig/kernel/printk.c
> +++ linux-2.6.18-rc5-mm1/kernel/printk.c
> @@ -713,11 +713,6 @@ void suspend_console(void)
>  	printk("Suspending console(s)\n");
>  	acquire_console_sem();
>  	console_suspended = 1;
> -	/* This is needed so that all of the messages that have already been
> -	 * written to all consoles can be actually transmitted (eg. over a
> -	 * network) before we try to suspend the consoles' devices.
> -	 */
> -	ssleep(2);
>  }
>  
>  void resume_console(void)

-- 
Stefan Seyfried
QA / R&D Team Mobile Devices        |              "Any ideas, John?"
SUSE LINUX Products GmbH, Nürnberg  | "Well, surrounding them's out."