72 lines
2.6 KiB
Diff
72 lines
2.6 KiB
Diff
From d087440dbd07fea5c5c52015b93fc46ce8a96d5f Mon Sep 17 00:00:00 2001
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Message-Id: <d087440dbd07fea5c5c52015b93fc46ce8a96d5f.1507911923.git.Jim.Somerville@windriver.com>
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In-Reply-To: <0bd66eb88c950d172a7dcefc61cb2e89b89cacce.1507911922.git.Jim.Somerville@windriver.com>
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References: <0bd66eb88c950d172a7dcefc61cb2e89b89cacce.1507911922.git.Jim.Somerville@windriver.com>
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From: Alex Shi <alex.shi@linaro.org>
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Date: Thu, 12 Jan 2017 21:27:04 +0800
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Subject: [PATCH 20/26] cpuidle/menu: add per CPU PM QoS resume latency
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consideration
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[ commit 9908859acaa95640d4a07991a93f7cd5bfc18e02 from linux-stable ]
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There may be special requirements on CPU response time, like if
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a interrupt is pinned to a CPU, that CPU should not go into excessively deep
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idle states. For this reason, add a mechanism for adding PM QoS resume
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latency constraints for individual CPUs and modify the menu governor to take
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them into account.
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To that end, extend the device PM QoS pm_qos_resume_latency attribute
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to CPUs, which is possible, because the exit latency for CPUs is
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effectively equivalent to the resume latency for devices.
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Signed-off-by: Alex Shi <alex.shi@linaro.org>
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Acked-by: Rik van Riel <riel@redhat.com>
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[ rjw : Subject & changelog ]
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Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Signed-off-by: Alex Kozyrev <alex.kozyrev@windriver.com>
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Signed-off-by: Jim Somerville <Jim.Somerville@windriver.com>
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---
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drivers/cpuidle/governors/menu.c | 7 +++++++
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1 file changed, 7 insertions(+)
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diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
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index eb9fb0e..fe2dcb8 100644
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--- a/drivers/cpuidle/governors/menu.c
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+++ b/drivers/cpuidle/governors/menu.c
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@@ -19,6 +19,7 @@
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#include <linux/tick.h>
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#include <linux/sched.h>
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#include <linux/math64.h>
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+#include <linux/cpu.h>
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#include <linux/module.h>
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#define BUCKETS 12
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@@ -259,10 +260,12 @@ again:
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static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
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{
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struct menu_device *data = &__get_cpu_var(menu_devices);
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+ struct device *device = get_cpu_device(dev->cpu);
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int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
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int i;
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int multiplier;
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struct timespec t;
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+ int resume_latency = dev_pm_qos_read_value(device);
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if (data->needs_update) {
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menu_update(drv, dev);
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@@ -271,6 +274,10 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
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data->exit_us = 0;
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+ /* resume_latency is 0 means no restriction */
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+ if (resume_latency && resume_latency < latency_req)
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+ latency_req = resume_latency;
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+
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/* Special case when user has set very strict latency requirement */
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if (unlikely(latency_req == 0))
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return 0;
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--
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1.8.3.1
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