linux-kernel - Re: [PATCH -v2 1/2] ratelimit: Extend to print suppressed messages on release

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Message-ID: <20160701101743.GA8787@gmail.com>
Date:	Fri, 1 Jul 2016 12:17:43 +0200
From:	Ingo Molnar <mingo@...nel.org>
To:	Borislav Petkov <bp@...en8.de>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>, Franck Bui <fbui@...e.com>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH -v2 1/2] ratelimit: Extend to print suppressed messages
 on release


* Borislav Petkov <bp@...en8.de> wrote:

> On Fri, Jul 01, 2016 at 10:22:47AM +0200, Ingo Molnar wrote:
> > > +/* issue num suppressed message on exit */
> > > +#define RATELIMIT_MSG_ON_RELEASE	BIT(0)
> > 
> > So this flag says that we should issue a ratelimit message when it occurs.
> 
> This flag says that we should print the ratelimit message when we
> release the ratelimit state, i.e., devkmsg_release() for example.
> 
> > But here we print the message if the RATELIMIT_MSG_ON_RELEASE bit is zero.
> > Is that intentional?
> 
> Sure, we want to dump the ratelimited messages only when we release the
> ratelimit state.

ah, I see, I was being dim - never mind!

> > Also, while we are changing it, I'd like to suggest a different message - it's 
> > talking about 'callbacks' but there's no callback here - we are skipping kernel 
> > log messages. So how about:
> > 
> > 	pr_warn("%s: %d kernel log lines skipped, due to rate-limiting.\n"
> 
> Well, I'm not sure: even though the majority of the ratelimit usage is
> printing stuff and it has been carved out from printk.c, it still is a
> generic facility and you probably want to ratelimit other things too
> with it, like polling for something or whatnot.

Yeah, indeed, you are right.

Thanks,

	Ingo