On Fri, 7 Feb 2014 16:26:01 -0500 Johannes Weiner <han...@cmpxchg.org> wrote:

> On Fri, Feb 07, 2014 at 12:31:29PM -0800, Andrew Morton wrote:
> > On Fri, 7 Feb 2014 13:13:32 -0500 Johannes Weiner <han...@cmpxchg.org> 
> > wrote:
> > 
> > > @@ -63,6 +64,9 @@ int drop_caches_sysctl_handler(ctl_table *table, int 
> > > write,
> > >                   iterate_supers(drop_pagecache_sb, NULL);
> > >           if (sysctl_drop_caches & 2)
> > >                   drop_slab();
> > > +         printk_ratelimited(KERN_INFO "%s (%d): dropped kernel caches: 
> > > %d\n",
> > > +                            current->comm, task_pid_nr(current),
> > > +                            sysctl_drop_caches);
> > >   }
> > >   return 0;
> > >  }
> > 
> > My concern with this is that there may be people whose
> > other-party-provided software uses drop_caches.  Their machines will
> > now sit there emitting log messages and there's nothing they can do
> > about it, apart from whining at their vendors.
> 
> Ironically, we have a customer that is complaining that we currently
> do not log these events, and they want to know who in their stack is
> being idiotic.

Right.  But if we release a kernel which goes blah on every write to
drop_caches, that customer has logs full of blahs which they are
now totally uninterested in.

> > We could do something like this?
> 
> They can already change the log level.

Suppressing unrelated things...

>  The below will suppress
> valuable debugging information in a way that still results in
> inconspicuous looking syslog excerpts, which somewhat undermines the
> original motivation for this change.

Yes, somewhat.  It is a compromise. You can see my concern here?


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to