Re: [PATCH 0/5] Rework system pressure interface to the scheduler

[Lukasz Luba]

On 12/14/23 08:32, Lukasz Luba wrote:
> On 12/14/23 08:29, Vincent Guittot wrote:
> > On Thu, 14 Dec 2023 at 09:21, Lukasz Luba <lukasz.luba@xxxxxxx> 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@xxxxxxxxxx/
> > > >
> > > > 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.

I've tested your patches with: DTPM/PowerCap + thermal gov + cpufreq
sysfs scaling_max_freq. It works fine all my cases (couldn't cause
any issues). If you like to test DTPM you will need 2 fixed pending
in Rafael's tree.

So, I'm looking for a your v2 to continue reviewing it.