From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH] CPUIdle: Reevaluate C-states under CPU load to favor deeper C-states Date: Tue, 20 Mar 2012 10:49:45 -0700 Message-ID: <878viv17t2.fsf@ti.com> References: <1316475315-5905-1-git-send-email-khilman@ti.com> <87d3d75zo6.fsf@ti.com> <4EBA6046.2060305@linux.vnet.ibm.com> <37CAE120BAE10B42A790DD1418C8021D0136C7@DNCE02.ent.ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from na3sys009aob106.obsmtp.com ([74.125.149.76]:51910 "EHLO na3sys009aog106.obsmtp.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751677Ab2CTRtr convert rfc822-to-8bit (ORCPT ); Tue, 20 Mar 2012 13:49:47 -0400 Received: by dakl33 with SMTP id l33so325201dak.31 for ; Tue, 20 Mar 2012 10:49:46 -0700 (PDT) In-Reply-To: (melwyn lobo's message of "Tue, 20 Mar 2012 20:19:02 +0530") Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: melwyn lobo Cc: "Chalhoub, Nicole" , Deepthi Dharwar , "linux-kernel@vger.kernel.org" , "linux-pm@lists.linux-foundation.org" , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Arjan van de Ven melwyn lobo writes: > Hey Kevin, > I would like to try out this patch in my platform see the benefits > that you are reporting. But there is one issue in this patch. You hav= e > not initialized "hrtimer_timeout" variable. > This will always be 0 right ?. Correct. The generic code defaults to zero so that the default behavior with thi= s patch is unchanged from previous behavior. In order to use this feature, your platform-specific code which creates your C-states sets the per-C-state timer values. Kevin > Thanks, > -M > > On Wed, Nov 9, 2011 at 11:36 PM, Chalhoub, Nicole = wrote: >> Hi Deepthi, >> >>> >> Texas Instruments France SA, 821 Avenue Jack Kilby, 06270 Villeneuve= Loubet. 036 420 040 R.C.S Antibes. Capital de EUR 753.920 >> >> -----Original Message----- >>> From: Deepthi Dharwar [mailto:deepthi@linux.vnet.ibm.com] >>> Sent: Wednesday, November 09, 2011 12:13 PM >>> To: Hilman, Kevin >>> Cc: linux-kernel@vger.kernel.org; Arjan van de Ven; linux-arm- >>> kernel@lists.infradead.org; linux-omap@vger.kernel.org; linux- >>> pm@lists.linux-foundation.org; Chalhoub, Nicole >>> Subject: Re: [PATCH] CPUIdle: Reevaluate C-states under CPU load to= favor >>> deeper C-states >> >> [...] >>> By setting timers when we enter non-deepest C-state possible, such = that >>> when it fires we >>> can re-evaluate and try moving into deeper and deeper C-states enha= ncing >>> the >>> power savings is a good feature to have. >>> >>> Looking at the current implementation, is it possible to have it as >>> configurable option >>> where one can enable/disable this functionality through the backhan= d >>> driver ? >> >> The timeout values of the c state timers are set in the backhand dri= ver. >> By setting the timeout to 0 the timers will not fire so you'll not h= ave this functionality enabled >> >>> Also I am thinking, instead of having them in governor >>> wouldnt it be a good idea to have it implemented in >>> the backhand driver itself ? >>> --Deepthi >> >> >> In fact each C-state had its own configurable timer, so it is a para= meter characterizing a C-state as it is for the exit_latency and target= _residency parameters. >> And we wanted the timer to fire only when we do not go in deep Cstat= e due to a high load. This decision is made in the CPU idle governor. S= o the functionality should be seen from the governor.. >> >> Thanks and Regards >> Nicole >> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kern= el" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at =C2=A0http://vger.kernel.org/majordomo-info.h= tml >> Please read the FAQ at =C2=A0http://www.tux.org/lkml/ > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html