From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rajendra Nayak Subject: Re: [PATCH 2/4] cpuidle: define the enter function in the driver structure Date: Tue, 10 Jul 2012 18:08:46 +0530 Message-ID: <4FFC2256.5050305@linaro.org> References: <1341494608-16591-1-git-send-email-daniel.lezcano@linaro.org> <1341494608-16591-2-git-send-email-daniel.lezcano@linaro.org> <201207052238.44330.rjw@sisk.pl> <4FF6C4C1.7030004@linaro.org> <4FFBE7E3.8020809@linaro.org> <4FFC147C.4050508@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ob0-f174.google.com ([209.85.214.174]:32977 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753079Ab2GJMiw (ORCPT ); Tue, 10 Jul 2012 08:38:52 -0400 Received: by obbuo13 with SMTP id uo13so22106890obb.19 for ; Tue, 10 Jul 2012 05:38:52 -0700 (PDT) In-Reply-To: <4FFC147C.4050508@linaro.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Daniel Lezcano Cc: "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, linux-pm@lists.linux-foundation.org, linaro-dev@lists.linaro.org, lenb@kernel.org > As the architectures tend to add more cores [1][2], that means more > memory consumption. In a very near future, we will have 100 cores in a > cpu. Assuming we have 4 C-states, that is 100 * 4 * 8 = 3200 bytes of > memory used for a single function. IMHO, the kernel shouldn't assume the > user must add more memory on the system. I completely agree. > > Anyway, I will post a patchset to use the cpuidle_state per cpu. Maybe what you were doing wasn't clearly evident with the existing cpuidle core, but once its scaled to add a per cpu state, it might look more meaningful. So if you post your patches to add cpuidle state per cpu, it should certainly give more insight into why this cleanup makes sense. > > Thanks > -- Daniel > > [1] http://www.engadget.com/2007/02/11/intel-demonstrates-80-core-processor/ > [2] http://www.tilera.com/products/processors/TILE-Gx_Family >