From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Michal Hocko <mhocko@suse.cz>,
linux-mm@kvack.org,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] add some drop_caches documentation and info messsge
Date: Thu, 25 Oct 2012 22:16:58 +0200 [thread overview]
Message-ID: <1484035.7aMAWXqOf7@vostro.rjw.lan> (raw)
In-Reply-To: <20121024181752.de011615.akpm@linux-foundation.org>
On Wednesday, October 24, 2012 06:17:52 PM Andrew Morton wrote:
> On Thu, 25 Oct 2012 00:04:46 +0200 "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
>
> > On Wednesday 24 of October 2012 14:13:03 Andrew Morton wrote:
> > > On Wed, 24 Oct 2012 23:06:00 +0200
> > > Borislav Petkov <bp@alien8.de> wrote:
> > >
> > > > On Wed, Oct 24, 2012 at 01:48:36PM -0700, Andrew Morton wrote:
> > > > > Well who knows. Could be that people's vm *does* suck. Or they have
> > > > > some particularly peculiar worklosd or requirement[*]. Or their VM
> > > > > *used* to suck, and the drop_caches is not really needed any more but
> > > > > it's there in vendor-provided code and they can't practically prevent
> > > > > it.
> > > >
> > > > I have drop_caches in my suspend-to-disk script so that the hibernation
> > > > image is kept at minimum and suspend times are as small as possible.
> > >
> > > hm, that sounds smart.
> > >
> > > > Would that be a valid use-case?
> > >
> > > I'd say so, unless we change the kernel to do that internally. We do
> > > have the hibernation-specific shrink_all_memory() in the vmscan code.
> > > We didn't see fit to document _why_ that exists, but IIRC it's there to
> > > create enough free memory for hibernation to be able to successfully
> > > complete, but no more.
> >
> > That's correct.
>
> Well, my point was: how about the idea of reclaiming clean pagecache
> (and inodes, dentries, etc) before hibernation so we read/write less
> disk data?
We may actually want to write more into the image to improve post-resume
responsiveness.
> Given that it's so easy to do from the hibernation script, I guess
> there's not much point...
Well, I'd say so. :-)
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
next prev parent reply other threads:[~2012-10-25 20:13 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-12 12:57 [PATCH] add some drop_caches documentation and info messsge Michal Hocko
2012-10-12 18:54 ` KOSAKI Motohiro
2012-10-15 9:04 ` Kamezawa Hiroyuki
2012-10-15 14:05 ` Dave Hansen
2012-10-23 23:45 ` Andrew Morton
2012-10-24 6:29 ` Michal Hocko
2012-10-24 19:54 ` Andrew Morton
2012-10-24 20:28 ` Dave Hansen
2012-10-24 20:48 ` Andrew Morton
2012-10-24 21:06 ` Borislav Petkov
2012-10-24 21:13 ` Andrew Morton
2012-10-24 22:04 ` Rafael J. Wysocki
2012-10-25 1:17 ` Andrew Morton
2012-10-25 20:16 ` Rafael J. Wysocki [this message]
2012-10-29 8:59 ` Jiri Kosina
2012-10-29 9:58 ` Borislav Petkov
2012-10-29 10:01 ` Jiri Kosina
2012-10-29 10:11 ` Borislav Petkov
2012-10-31 17:31 ` Pavel Machek
2012-10-31 17:46 ` Borislav Petkov
2012-10-24 22:35 ` KOSAKI Motohiro
2012-10-25 14:21 ` Michal Hocko
2012-10-24 21:18 ` Dave Hansen
2012-10-24 22:48 ` Borislav Petkov
2012-10-24 22:57 ` Dave Hansen
2012-10-25 0:56 ` KOSAKI Motohiro
2012-10-25 9:24 ` Borislav Petkov
2012-10-25 11:57 ` Dave Hansen
2012-10-25 14:24 ` Borislav Petkov
2012-10-25 14:25 ` Michal Hocko
2012-10-26 7:45 ` Mika Boström
2012-11-01 20:26 ` Pavel Machek
2012-10-25 14:09 ` Michal Hocko
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