Re: Checking page_count(page) in invalidate_complete_page

Andrew Morton
2006-10-03T04:24:00Z

On Tue, 03 Oct 2006 00:18:37 -0400
Trond Myklebust <Trond.Myklebust@netapp.com> wrote:

> On Mon, 2006-10-02 at 22:14 -0400, Chuck Lever wrote:
> > Steve Dickson wrote:
> > > Andrew Morton wrote:
> > >>
> > >> This is our user's data we're talking about here.
> > > Point...
> > >
> > >>
> > >> If that printk comes out then we need to fix the kernel so that it no
> > >> longer wants to print that printk. We don't want to just hide it.
>
> So what _is_ stopping us from fixing it right now? Are we missing an
> audit of the possible errors? That can be arranged...

We hope that it'll never come out.

> > > I'm concern about the printk popping when we are flushing the
> > > readdir cache (i.e. stale data) and either flooding the console
> > > to a ton a messages (basically bring a system to its knees for
> > > no good reason) or scaring the hell out people by saying we have a
> > > major problem when in reality we are just flushing stale data...
> > >
> > > So I definitely agree the printk should be there and be on by default,
> > > but I so think it would be a good idea to have way to turn it off
> > > if need be...
>
> Why? If we know there is a problem, then why wait to fix it?

There is now no known problem. But as I said before, this is an area where
we've had relatively frequent problems, and those problems are subtle.

So the printk is just an early warning system.