Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754875Ab3IZBVc (ORCPT ); Wed, 25 Sep 2013 21:21:32 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51937 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751107Ab3IZBVb (ORCPT ); Wed, 25 Sep 2013 21:21:31 -0400 Date: Wed, 25 Sep 2013 18:21:29 -0700 From: Andrew Morton To: Arjan van de Ven Cc: Andi Kleen , "Srivatsa S. Bhat" , mgorman@suse.de, dave@sr71.net, hannes@cmpxchg.org, tony.luck@intel.com, matthew.garrett@nebula.com, riel@redhat.com, srinivas.pandruvada@linux.intel.com, willy@linux.intel.com, kamezawa.hiroyu@jp.fujitsu.com, lenb@kernel.org, rjw@sisk.pl, gargankita@gmail.com, paulmck@linux.vnet.ibm.com, svaidy@linux.vnet.ibm.com, isimatu.yasuaki@jp.fujitsu.com, santosh.shilimkar@ti.com, kosaki.motohiro@gmail.com, linux-pm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [Results] [RFC PATCH v4 00/40] mm: Memory Power Management Message-Id: <20130925182129.a7db6a0fd2c7cc3b43fda92d@linux-foundation.org> In-Reply-To: <52438AA9.3020809@linux.intel.com> References: <20130925231250.26184.31438.stgit@srivatsabhat.in.ibm.com> <52437128.7030402@linux.vnet.ibm.com> <20130925164057.6bbaf23bdc5057c42b2ab010@linux-foundation.org> <20130925234734.GK18242@two.firstfloor.org> <52438AA9.3020809@linux.intel.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1007 Lines: 22 On Wed, 25 Sep 2013 18:15:21 -0700 Arjan van de Ven wrote: > On 9/25/2013 4:47 PM, Andi Kleen wrote: > >> Also, the changelogs don't appear to discuss one obvious downside: the > >> latency incurred in bringing a bank out of one of the low-power states > >> and back into full operation. Please do discuss and quantify that to > >> the best of your knowledge. > > > > On Sandy Bridge the memry wakeup overhead is really small. It's on by default > > in most setups today. > > btw note that those kind of memory power savings are content-preserving, > so likely a whole chunk of these patches is not actually needed on SNB > (or anything else Intel sells or sold) (head spinning a bit). Could you please expand on this rather a lot? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/