From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx161.postini.com [74.125.245.161]) by kanga.kvack.org (Postfix) with SMTP id C3D6E6B0044 for ; Wed, 24 Oct 2012 17:13:04 -0400 (EDT) Date: Wed, 24 Oct 2012 14:13:03 -0700 From: Andrew Morton Subject: Re: [PATCH] add some drop_caches documentation and info messsge Message-Id: <20121024141303.0797d6a1.akpm@linux-foundation.org> In-Reply-To: <20121024210600.GA17037@liondog.tnic> References: <20121012125708.GJ10110@dhcp22.suse.cz> <20121023164546.747e90f6.akpm@linux-foundation.org> <20121024062938.GA6119@dhcp22.suse.cz> <20121024125439.c17a510e.akpm@linux-foundation.org> <50884F63.8030606@linux.vnet.ibm.com> <20121024134836.a28d223a.akpm@linux-foundation.org> <20121024210600.GA17037@liondog.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Borislav Petkov Cc: Dave Hansen , Michal Hocko , linux-mm@kvack.org, KAMEZAWA Hiroyuki , KOSAKI Motohiro , LKML , "Rafael J. Wysocki" On Wed, 24 Oct 2012 23:06:00 +0200 Borislav Petkov 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. Who owns hibernaton nowadays? Rafael, I guess? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org