Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761998AbYHFBwp (ORCPT ); Tue, 5 Aug 2008 21:52:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760012AbYHFBvd (ORCPT ); Tue, 5 Aug 2008 21:51:33 -0400 Received: from mga02.intel.com ([134.134.136.20]:29578 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759031AbYHFBvc convert rfc822-to-8bit (ORCPT ); Tue, 5 Aug 2008 21:51:32 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.31,314,1215414000"; d="scan'208";a="426374744" Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT X-MimeOLE: Produced By Microsoft Exchange V6.5 Subject: RE: [linux-pm] [RFC-PATCH] Improve Menu Governor Prediction of interrupted C states. Date: Wed, 6 Aug 2008 09:51:14 +0800 Message-ID: <094BCE01AFBE9646AF220B0B3F367AAB035B08D0@pdsmsx413.ccr.corp.intel.com> In-Reply-To: <13B9B4C6EF24D648824FF11BE89671620361F4E439@dlee02.ent.ti.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [linux-pm] [RFC-PATCH] Improve Menu Governor Prediction of interrupted C states. Thread-Index: Acjl9NwKQ0on4gDvSK+0rYSuOpnIRwFzHyfwAuhi8pAAALobgA== References: <13B9B4C6EF24D648824FF11BE8967162035BEA0EDF@dlee02.ent.ti.com> <094BCE01AFBE9646AF220B0B3F367AAB034DBB7A@pdsmsx413.ccr.corp.intel.com> <13B9B4C6EF24D648824FF11BE89671620361F4E439@dlee02.ent.ti.com> From: "Wei, Gang" To: "Woodruff, Richard" , "Linux Power Management List" Cc: "Linux Kernel Mailing List" X-OriginalArrivalTime: 06 Aug 2008 01:51:16.0358 (UTC) FILETIME=[E9EFA260:01C8F766] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1285 Lines: 31 > Hi, > >> I also found current cpuidle Menu governor should have some problems >> while predicting next non-expected break-event after some expected >> break-events. The measured_us/elapsed_us/predicted_us will become larger >> and larger once (measured_us + BREAK_FUZZ >= data->expected_us - >> target->exit_latency). The major point is that it should be >> last_residency, not measured_us, that need to be used to do comparing >> and distinguish between expected & non-expected events. >> >> Below is my draft patch (not tested) for this. It is simple and should >> also be effective for high interrupt rates case. > > This does seem to give better guesses. However, first tests are not showing > as well as the irq time stamp version I posted. > > I'll need to grab some hardware trace to see what is going on. Thanks for the trial. My original patch has already been merged into another patch "[patch 2/3] cpuidle: Menu governor fix wrong usage of measured_us" sent out by Venkatesh. The new patch should be more intact. Jimmy -- 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/