Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753724AbaGPWfc (ORCPT ); Wed, 16 Jul 2014 18:35:32 -0400 Received: from smtp.codeaurora.org ([198.145.11.231]:47450 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751710AbaGPWf2 (ORCPT ); Wed, 16 Jul 2014 18:35:28 -0400 Message-ID: <53C6FE2F.8080408@codeaurora.org> Date: Wed, 16 Jul 2014 15:35:27 -0700 From: Saravana Kannan User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 MIME-Version: 1.0 To: "Rafael J. Wysocki" CC: Viresh Kumar , Todd Poynor , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] cpufreq: Don't destroy/realloc policy/sysfs on hotplug/suspend References: <1404959850-11617-1-git-send-email-skannan@codeaurora.org> <16164926.ZsJxe6UV3e@vostro.rjw.lan> In-Reply-To: <16164926.ZsJxe6UV3e@vostro.rjw.lan> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/16/2014 03:02 PM, Rafael J. Wysocki wrote: > On Wednesday, July 09, 2014 07:37:30 PM Saravana Kannan wrote: >> Preliminary patch. Not tested. Just sending out to give an idea of what I'm >> looking to do. Expect a lot more simplification when it's done. >> >> Benefits: >> * A lot more simpler code. >> * Less stability issues. >> * Suspend/resume time would improve. >> * Hotplug time would improve. >> * Sysfs file permissions would be maintained. >> * More policy settings would be maintained across suspend/resume. >> * cpufreq stats would be maintained across hotplug for all CPUs. > > One problem. The real hotplug (when the CPU actually goes away) depends on > offline removing all that stuff for it. How are you going to address that? policy, sysfs and kobj are just SW state inside cpufreq core. So, that shouldn't really affect what happens in HW when the CPU really is hotplugged. Can you please elaborate what you mean? The only thing that this code assumes is that in real hotplug case too, that the /sys/system/devices/cpuX directory doesn't go away. I don't think it does. Does it? -Saravana -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation -- 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/