[PATCH 0/5] Rework system pressure interface to the scheduler
Lukasz Luba
lukasz.luba at arm.com
Thu Dec 14 00:32:38 PST 2023
On 12/14/23 08:29, Vincent Guittot wrote:
> On Thu, 14 Dec 2023 at 09:21, Lukasz Luba <lukasz.luba at arm.com> wrote:
>>
>> Hi Vincent,
>>
>> I've been waiting for this feature, thanks!
>>
>>
>> On 12/12/23 14:27, Vincent Guittot wrote:
>>> Following the consolidation and cleanup of CPU capacity in [1], this serie
>>> reworks how the scheduler gets the pressures on CPUs. We need to take into
>>> account all pressures applied by cpufreq on the compute capacity of a CPU
>>> for dozens of ms or more and not only cpufreq cooling device or HW
>>> mitigiations. we split the pressure applied on CPU's capacity in 2 parts:
>>> - one from cpufreq and freq_qos
>>> - one from HW high freq mitigiation.
>>>
>>> The next step will be to add a dedicated interface for long standing
>>> capping of the CPU capacity (i.e. for seconds or more) like the
>>> scaling_max_freq of cpufreq sysfs. The latter is already taken into
>>> account by this serie but as a temporary pressure which is not always the
>>> best choice when we know that it will happen for seconds or more.
>>>
>>> [1] https://lore.kernel.org/lkml/20231211104855.558096-1-vincent.guittot@linaro.org/
>>>
>>> Vincent Guittot (4):
>>> cpufreq: Add a cpufreq pressure feedback for the scheduler
>>> sched: Take cpufreq feedback into account
>>> thermal/cpufreq: Remove arch_update_thermal_pressure()
>>> sched: Rename arch_update_thermal_pressure into
>>> arch_update_hw_pressure
>>>
>>> arch/arm/include/asm/topology.h | 6 +--
>>> arch/arm64/include/asm/topology.h | 6 +--
>>> drivers/base/arch_topology.c | 26 ++++-----
>>> drivers/cpufreq/cpufreq.c | 48 +++++++++++++++++
>>> drivers/cpufreq/qcom-cpufreq-hw.c | 4 +-
>>> drivers/thermal/cpufreq_cooling.c | 3 --
>>> include/linux/arch_topology.h | 8 +--
>>> include/linux/cpufreq.h | 10 ++++
>>> include/linux/sched/topology.h | 8 +--
>>> .../{thermal_pressure.h => hw_pressure.h} | 14 ++---
>>> include/trace/events/sched.h | 2 +-
>>> init/Kconfig | 12 ++---
>>> kernel/sched/core.c | 8 +--
>>> kernel/sched/fair.c | 53 ++++++++++---------
>>> kernel/sched/pelt.c | 18 +++----
>>> kernel/sched/pelt.h | 16 +++---
>>> kernel/sched/sched.h | 4 +-
>>> 17 files changed, 152 insertions(+), 94 deletions(-)
>>> rename include/trace/events/{thermal_pressure.h => hw_pressure.h} (55%)
>>>
>>
>> I would like to test it, but something worries me. Why there is 0/5 in
>> this subject and only 4 patches?
>
> I removed a patch from the series but copied/pasted the cover letter
> subject without noticing the /5 instead of /4
OK
>
>>
>> Could you tell me your base branch that I can apply this, please?
>
> It applies on top of tip/sched/core + [1]
> and you can find it here:
> https://git.linaro.org/people/vincent.guittot/kernel.git/log/?h=sched/system-pressure
Thanks for the info and handy link.
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