From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [Results] [RFC PATCH v4 00/40] mm: Memory Power Management Date: Wed, 25 Sep 2013 16:40:57 -0700 Message-ID: <20130925164057.6bbaf23bdc5057c42b2ab010@linux-foundation.org> References: <20130925231250.26184.31438.stgit@srivatsabhat.in.ibm.com> <52437128.7030402@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51076 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753490Ab3IYXk7 (ORCPT ); Wed, 25 Sep 2013 19:40:59 -0400 In-Reply-To: <52437128.7030402@linux.vnet.ibm.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Srivatsa S. Bhat" Cc: mgorman@suse.de, dave@sr71.net, hannes@cmpxchg.org, tony.luck@intel.com, matthew.garrett@nebula.com, riel@redhat.com, arjan@linux.intel.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, andi@firstfloor.org, 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 On Thu, 26 Sep 2013 04:56:32 +0530 "Srivatsa S. Bhat" wrote: > Experimental Results: > ==================== > > Test setup: > ---------- > > x86 Sandybridge dual-socket quad core HT-enabled machine, with 128GB RAM. > Memory Region size = 512MB. Yes, but how much power was saved ;) 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.