Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965110AbbKCWe1 (ORCPT ); Tue, 3 Nov 2015 17:34:27 -0500 Received: from shelob.surriel.com ([74.92.59.67]:39271 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964813AbbKCWeY (ORCPT ); Tue, 3 Nov 2015 17:34:24 -0500 From: riel@redhat.com To: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, rafael.j.wysocki@intel.com, arjan@linux.intel.com, len.brown@intel.com, daniel.lezcano@linaro.org Subject: [PATCH 2/3] cpuidle,menu: use interactivity_req to disable polling Date: Tue, 3 Nov 2015 17:34:18 -0500 Message-Id: <1446590059-18897-3-git-send-email-riel@redhat.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1446590059-18897-1-git-send-email-riel@redhat.com> References: <1446590059-18897-1-git-send-email-riel@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1816 Lines: 44 From: Rik van Riel The menu governor carefully figures out how much time we typically sleep for an estimated sleep interval, or whether there is a repeating pattern going on, and corrects that estimate for the CPU load. Then it proceeds to ignore that information when determining whether or not to consider polling. This is not a big deal on most x86 CPUs, which have very low C1 latencies, and the patch should not have any effect on those CPUs. However, certain CPUs (eg. Atom) have much higher C1 latencies, and it would be good to not waste performance and power on those CPUs if we are expecting a very low wakeup latency. Disable polling based on the estimated interactivity requirement, not on the time to the next timer interrupt. Signed-off-by: Rik van Riel --- drivers/cpuidle/governors/menu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index ecc242a586c9..b1a55731f921 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -330,7 +330,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) * We want to default to C1 (hlt), not to busy polling * unless the timer is happening really really soon. */ - if (data->next_timer_us > 20 && + if (interactivity_req > 20 && !drv->states[CPUIDLE_DRIVER_STATE_START].disabled && dev->states_usage[CPUIDLE_DRIVER_STATE_START].disable == 0) data->last_state_idx = CPUIDLE_DRIVER_STATE_START; -- 2.1.0 -- 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/