From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta8.messagelabs.com (mail6.bemta8.messagelabs.com [216.82.243.55]) by kanga.kvack.org (Postfix) with ESMTP id 141B66B004A for ; Fri, 10 Jun 2011 13:06:13 -0400 (EDT) Date: Fri, 10 Jun 2011 18:05:35 +0100 From: Matthew Garrett Subject: Re: [PATCH 00/10] mm: Linux VM Infrastructure to support Memory Power Management Message-ID: <20110610170535.GC25774@srcf.ucam.org> References: <1306499498-14263-1-git-send-email-ankita@in.ibm.com> <20110528005640.9076c0b1.akpm@linux-foundation.org> <20110609185259.GA29287@linux.vnet.ibm.com> <20110610151121.GA2230@linux.vnet.ibm.com> <20110610155954.GA25774@srcf.ucam.org> <20110610165529.GC2230@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110610165529.GC2230@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Paul E. McKenney" Cc: Kyungmin Park , Andrew Morton , Ankita Garg , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-pm@lists.linux-foundation.org, svaidy@linux.vnet.ibm.com, thomas.abraham@linaro.org On Fri, Jun 10, 2011 at 09:55:29AM -0700, Paul E. McKenney wrote: > On Fri, Jun 10, 2011 at 04:59:54PM +0100, Matthew Garrett wrote: > > For the server case, the low hanging fruit would seem to be > > finer-grained self-refresh. At best we seem to be able to do that on a > > per-CPU socket basis right now. The difference between active and > > self-refresh would seem to be much larger than the difference between > > self-refresh and powered down. > > By "finer-grained self-refresh" you mean turning off refresh for banks > of memory that are not being used, right? If so, this is supported by > the memory-regions support provided, at least assuming that the regions > can be aligned with the self-refresh boundaries. I mean at the hardware level. As far as I know, the best we can do at the moment is to put an entire node into self refresh when the CPU hits package C6. -- Matthew Garrett | mjg59@srcf.ucam.org -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org