From: Dave Hansen <dave@linux.vnet.ibm.com>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
lnxninja@linux.vnet.ibm.com
Subject: Re: [RFC][PATCH] update /proc/sys/vm/drop_caches documentation
Date: Tue, 14 Sep 2010 23:14:22 -0700 [thread overview]
Message-ID: <1284531262.27089.15725.camel@nimitz> (raw)
In-Reply-To: <20100915135016.C9F1.A69D9226@jp.fujitsu.com>
On Wed, 2010-09-15 at 13:53 +0900, KOSAKI Motohiro wrote:
> > > ==============================================================
> > >
> > > diff -puN fs/drop_caches.c~update-drop_caches-documentation fs/drop_caches.c
> > > --- linux-2.6.git/fs/drop_caches.c~update-drop_caches-documentation 2010-09-14 15:44:29.000000000 -0700
> > > +++ linux-2.6.git-dave/fs/drop_caches.c 2010-09-14 15:58:31.000000000 -0700
> > > @@ -47,6 +47,8 @@ int drop_caches_sysctl_handler(ctl_table
> > > {
> > > proc_dointvec_minmax(table, write, buffer, length, ppos);
> > > if (write) {
> > > + WARN_ONCE(1, "kernel caches forcefully dropped, "
> > > + "see Documentation/sysctl/vm.txt\n");
> >
> > Documentation updeta seems good but showing warning seems to be meddling to me.
>
> Agreed.
>
> If the motivation is blog's bogus rumor, this is no effective. I easily
> imazine they will write "Hey, drop_caches may output strange message,
> but please ignore it!".
Fair enough. But, is there a point that we _should_ be warning? If
someone is doing this every minute, or every hour, something is pretty
broken. Should we at least be doing a WARN_ON() so that the TAINT_WARN
is set?
I'm worried that there are users out there experiencing real problems
that aren't reporting it because "workarounds" like this just paper over
the issue.
-- Dave
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next prev parent reply other threads:[~2010-09-15 6:14 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-14 23:47 [RFC][PATCH] update /proc/sys/vm/drop_caches documentation Dave Hansen
2010-09-15 4:33 ` KAMEZAWA Hiroyuki
2010-09-15 4:53 ` KOSAKI Motohiro
2010-09-15 6:14 ` Dave Hansen [this message]
2010-09-15 18:37 ` Eric W. Biederman
2010-09-15 19:27 ` Dave Hansen
2010-09-15 21:34 ` Eric W. Biederman
2010-09-15 19:24 ` Tim Pepper
2010-09-16 0:12 ` KAMEZAWA Hiroyuki
2010-09-16 1:21 ` Dave Hansen
2010-09-16 1:33 ` KAMEZAWA Hiroyuki
2010-09-24 13:02 ` Pavel Machek
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