From 9908859acaa95640d4a07991a93f7cd5bfc18e02 Mon Sep 17 00:00:00 2001 From: Alex Shi Date: Thu, 12 Jan 2017 21:27:04 +0800 Subject: [PATCH] cpuidle/menu: add per CPU PM QoS resume latency consideration There may be special requirements on CPU response time, like if a interrupt is pinned to a CPU, that CPU should not go into excessively deep idle states. For this reason, add a mechanism for adding PM QoS resume latency constraints for individual CPUs and modify the menu governor to take them into account. To that end, extend the device PM QoS pm_qos_resume_latency attribute to CPUs, which is possible, because the exit latency for CPUs is effectively equivalent to the resume latency for devices. Signed-off-by: Alex Shi Acked-by: Rik van Riel [ rjw : Subject & changelog ] Signed-off-by: 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 07e36bb54006..8d6d25c38c02 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 @@ again: 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; -- 2.20.1