From owner-freebsd-acpi@FreeBSD.ORG Fri Jul 5 05:05:36 2013 Return-Path: Delivered-To: acpi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 12606371; Fri, 5 Jul 2013 05:05:36 +0000 (UTC) (envelope-from kob6558@gmail.com) Received: from mail-oa0-x22b.google.com (mail-oa0-x22b.google.com [IPv6:2607:f8b0:4003:c02::22b]) by mx1.freebsd.org (Postfix) with ESMTP id C975210BE; Fri, 5 Jul 2013 05:05:35 +0000 (UTC) Received: by mail-oa0-f43.google.com with SMTP id i7so2807258oag.2 for ; Thu, 04 Jul 2013 22:05:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=Oiv4KGBAPIs/wCectPl9FDlel/a3VZc2ZUOwtyW9OSA=; b=OU5bnuTJC0lNyVuvPO602n7kf38xYwrdmb1QX1CqkSzImJmhaCZQhRWtkQGKb7aI+u JkGRaf3hFFJpZcUlZfuRDo58iyIiTqCK6lvZFDi5VDahsHogZ1pPduTUg+vxwKAILRZd CXNSVsaWZ1NabNsHT6D5FO6GaCydY2bMVinmX6UN5SiESrgLSCYc5ojfSd5baEKWna/o aav2KA+oobgsP2L2tLDAqPLBIIruRLepbgL1ShD7tCYIVGXn+DvRfZDR/iuA2jV1UO33 YzfqUr5kCzYDbkA9Ec0Hsbcxwr/9SBSjboUupXh9lfZJAFMqgHHLrgu+F4Pnp8dkqf2T NKRQ== MIME-Version: 1.0 X-Received: by 10.182.88.202 with SMTP id bi10mr9164521obb.91.1373000735403; Thu, 04 Jul 2013 22:05:35 -0700 (PDT) Sender: kob6558@gmail.com Received: by 10.76.112.212 with HTTP; Thu, 4 Jul 2013 22:05:35 -0700 (PDT) In-Reply-To: References: Date: Thu, 4 Jul 2013 22:05:35 -0700 X-Google-Sender-Auth: QV39Hd9l__BBjF0UcBBkfRMRTq4 Message-ID: Subject: Re: Hyper mode for powerd From: Kevin Oberman To: Warren Block Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: "freebsd-acpi@freebsd.org" , wblock@freebsd.org X-BeenThere: freebsd-acpi@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: ACPI and power management development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Jul 2013 05:05:36 -0000 On Thu, Jul 4, 2013 at 7:12 PM, Warren Block wrote: > Attached is a proposed patch for -head that adds a "hyper" mode to powerd. > Instead of slewing like the adaptive modes, this mode drops all the way to > the lowest frequency when the system is idle, and jumps all the way to the > highest frequency when there is any load. > > Subjectively, it seems more responsive for desktop use than hiadaptive > mode. That's hard to benchmark. Power usage is another question. This > mode might use less power than the adaptive modes, but that's also > difficult to benchmark. > > Comments welcome. > > I have not looked at the patch yet, but it should really only use EST and not TC or throttling as many systems, when throttled and put into deep sleep modes (C3 or lower) will hang. Studies have shown (sorry, but since I retired I have lost the papers on the subject) that best power efficiency is when the system is operated at minimum performance when idle and maximum when not, so this is probably a good idea for most any non-mobile system and most mobile system applications. There are cases when you may be willing to pay a response price to keep the battery alive a little longer when performing ongoing activities that don't need large amounts of CPU like listening to music. As I have often pointed out, TCC and throttling were never intended for power management and I strongly recommend that they be disabled. OTOH, deep sleep states are huge winners and should be used to their maximum. EST is a smaller win, but can make a system seem sluggish, especially when added to TCC or throttling. -- R. Kevin Oberman, Network Engineer E-mail: rkoberman@gmail.com