From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Shi Subject: [PATCH 3/3] cpuidle/menu: add per cpu pm_qos_resume_latency consideration Date: Thu, 12 Jan 2017 21:27:04 +0800 Message-ID: <1484227624-6740-4-git-send-email-alex.shi@linaro.org> References: <1484227624-6740-1-git-send-email-alex.shi@linaro.org> Return-path: Received: from mail-pf0-f169.google.com ([209.85.192.169]:35097 "EHLO mail-pf0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750796AbdALN12 (ORCPT ); Thu, 12 Jan 2017 08:27:28 -0500 Received: by mail-pf0-f169.google.com with SMTP id f144so13565445pfa.2 for ; Thu, 12 Jan 2017 05:27:28 -0800 (PST) In-Reply-To: <1484227624-6740-1-git-send-email-alex.shi@linaro.org> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Greg Kroah-Hartman , Daniel Lezcano , "Rafael J . Wysocki" , vincent.guittot@linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Alex Shi , Ulf Hansson , Rasmus Villemoes , Arjan van de Ven , Rik van Riel Kernel or user may have special requirement on cpu response time, like if a interrupt is pinned to a cpu, we don't want the cpu goes too deep sleep. This patch can prevent this thing happen by consider per cpu resume_latency setting in cpu sleep state selection in menu governor. The pm_qos_resume_latency ask device to give reponse in this time. That's similar with cpu cstates' entry_latency + exit_latency. But since most of cpu cstate either has no entry_latency or add it into exit_latency So, we just can restrict this time requirement as states exit_latency. We can set a wanted latency value according to the value of /sys/devices/system/cpu/cpuX/cpuidle/stateX/latency. to just a bit less than related state's latency value. Then cpu can get to this state or higher. Signed-off-by: Alex Shi To: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: Ulf Hansson Cc: Daniel Lezcano Cc: Rasmus Villemoes Cc: Arjan van de Ven Cc: Rik van Riel Cc: "Rafael J. Wysocki" --- drivers/cpuidle/governors/menu.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index 07e36bb..8d6d25c 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -19,6 +19,7 @@ #include #include #include +#include /* * Please note when changing the tuning values: @@ -280,17 +281,23 @@ static unsigned int get_typical_interval(struct menu_device *data) static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) { struct menu_device *data = this_cpu_ptr(&menu_devices); + struct device *device = get_cpu_device(dev->cpu); int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY); int i; unsigned int interactivity_req; unsigned int expected_interval; unsigned long nr_iowaiters, cpu_load; + int resume_latency = dev_pm_qos_read_value(device); if (data->needs_update) { menu_update(drv, dev); data->needs_update = 0; } + /* resume_latency is 0 means no restriction */ + if (resume_latency && resume_latency < latency_req) + latency_req = resume_latency; + /* Special case when user has set very strict latency requirement */ if (unlikely(latency_req == 0)) return 0; -- 2.8.1.101.g72d917a