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

From: Lukasz Luba
Date: Thu Dec 14 2023 - 03:31:54 EST




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.