Messages in this thread | | | Subject | Re: [PATCH 2/4] cpu: expose pm_qos_resume_latency for each cpu | From | Alex Shi <> | Date | Tue, 13 Sep 2016 21:57:28 +0800 |
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Cc Rafael,
This patchset is quit simple and straight. Is there any concern or hesitate on it?
Thanks Alex
On 09/01/2016 11:50 AM, Alex Shi wrote: > > Few commits and patch changed according to Greg's comments. > > Regards > Alex > > ==== > > From 186c534b0b8b9649fbfce05b0b4f90f764c571a4 Mon Sep 17 00:00:00 2001 > From: Alex Shi <alex.shi@linaro.org> > Date: Tue, 16 Aug 2016 15:29:01 +0800 > Subject: [PATCH 2/4] cpu: expose pm_qos_resume_latency for each cpu > > Adding /sys/devices/system/cpu/cpux/power/pm_qos_resume_latency_us for > each of cpus. The pm_qos_resume_latency usage defined in > Documentation/ABI/testing/sysfs-devices-power > > The cpu-dma PM QoS constraint impacts all the cpus in the system. There > is no way to let the user to choose a PM QoS constraint per cpu. > > The following patch exposes to the userspace a per cpu based sysfs file > in order to let the userspace to change the value of the PM QoS latency > constraint. > > This change is inoperative in its form and the cpuidle governors have to > take into account the per cpu latency constraint in addition to the > global cpu-dma latency constraint in order to operate properly. > > Signed-off-by: Alex Shi <alex.shi@linaro.org> > To: linux-kernel@vger.kernel.org > To: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: linux-pm@vger.kernel.org > Cc: Ulf Hansson <ulf.hansson@linaro.org> > Cc: Daniel Lezcano <daniel.lezcano@linaro.org> > --- > drivers/base/cpu.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c > index 4c28e1a..2c3b359 100644 > --- a/drivers/base/cpu.c > +++ b/drivers/base/cpu.c > @@ -17,6 +17,7 @@ > #include <linux/of.h> > #include <linux/cpufeature.h> > #include <linux/tick.h> > +#include <linux/pm_qos.h> > > #include "base.h" > > @@ -376,6 +377,7 @@ int register_cpu(struct cpu *cpu, int num) > > per_cpu(cpu_sys_devices, num) = &cpu->dev; > register_cpu_under_node(num, cpu_to_node(num)); > + dev_pm_qos_expose_latency_limit(&cpu->dev, 0); > > return 0; > } >
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