From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] serial8250: ratelimit "too much work" error
Date: Mon, 4 Oct 2010 16:11:39 -0700
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To: Joe Perches <joe@perches.com>
Cc: Daniel Drake <dsd@laptop.org>, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Alan Cox <alan@lxorguk.ukuu.org.uk>, Greg KH <greg@kroah.com>

On Mon, 04 Oct 2010 15:59:29 -0700
Joe Perches <joe@perches.com> wrote:

> On Mon, 2010-10-04 at 15:21 -0700, Andrew Morton wrote:
> > On Mon, 04 Oct 2010 15:10:59 -0700
> > Joe Perches <joe@perches.com> wrote:
> > > On Mon, 2010-10-04 at 15:02 -0700, Andrew Morton wrote:
> > > > On Mon, 4 Oct 2010 14:51:01 -0700
> > > > Andrew Morton <akpm@linux-foundation.org> wrote:
> > > > I'll give up and pronounce that users of printk_ratelimited() need to
> > > > include ratelimit.h as well.
> > > What I suggested several months ago was to move the
> > > macro definitions to ratelimit.h
> > > http://lkml.org/lkml/2010/2/18/377
> > That's a bit nasty because at present ratelimit.h is purely about
> > ratelimiting and knowns nothing about any of its clients.  At present
> > it has only one client (printk), but it could have more in the future!
> 
> Look at the structure, it's very specific to
> message logging functionality.
> 
> struct ratelimit_state {
> 	spinlock_t	lock;		/* protect the state */
> 
> 	int		interval;
> 	int		burst;
> 	int		printed;
> 	int		missed;
> 	unsigned long	begin;
> };

s/printed/hit/there,fixed

This is at present a quite general facility.

> I think it's likely that the current ratelimit
> will not be used for any other function.

Filling it up with printk-specific stuff will help ensure that.