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| author | Alex Shi <alex.shi@linaro.org> | 2017-01-12 21:27:04 +0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-01-30 11:03:32 +0100 |
| commit | 9908859acaa95640d4a07991a93f7cd5bfc18e02 (patch) | |
| tree | 4606265c8d2ea8ab3cea9c09c2f44aaf3604515c /drivers/cpuidle | |
| parent | 8e37e1a2a3295f5d99e6dbe99eca24eca7a034ef (diff) | |
| download | talos-obmc-linux-9908859acaa95640d4a07991a93f7cd5bfc18e02.tar.gz talos-obmc-linux-9908859acaa95640d4a07991a93f7cd5bfc18e02.zip | |
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 <alex.shi@linaro.org>
Acked-by: Rik van Riel <riel@redhat.com>
[ rjw : Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/governors/menu.c | 7 |
1 files changed, 7 insertions, 0 deletions
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 <linux/tick.h> #include <linux/sched.h> #include <linux/math64.h> +#include <linux/cpu.h> /* * 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; |
