On Mon, Aug 22, 2016 at 07:30:36PM +0200, Rafael J. Wysocki wrote:

On Saturday, August 20, 2016 05:40:49 PM Krzysztof Kozlowski wrote:

quoted

On Sat, Aug 20, 2016 at 03:08:01AM +0200, Rafael J. Wysocki wrote:

quoted

On Friday, August 19, 2016 03:26:21 PM Krzysztof Kozlowski wrote:

quoted

On Fri, Aug 12, 2016 at 2:04 AM, Rafael J. Wysocki [off-list ref] wrote:

quoted

From: Rafael J. Wysocki <redacted>

It is useful to know the reason why cpufreq_update_util() has just
been called and that can be passed as flags to cpufreq_update_util()
and to the ->func() callback in struct update_util_data.  However,
doing that in addition to passing the util and max arguments they
already take would be clumsy, so avoid it.

Instead, use the observation that the schedutil governor is part
of the scheduler proper, so it can access scheduler data directly.
This allows the util and max arguments of cpufreq_update_util()
and the ->func() callback in struct update_util_data to be replaced
with a flags one, but schedutil has to be modified to follow.

Thus make the schedutil governor obtain the CFS utilization
information from the scheduler and use the "RT" and "DL" flags
instead of the special utilization value of ULONG_MAX to track
updates from the RT and DL sched classes.  Make it non-modular
too to avoid having to export scheduler variables to modules at
large.

Next, update all of the other users of cpufreq_update_util()
and the ->func() callback in struct update_util_data accordingly.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <redacted>
---

v1 -> v2: Do not check cpu_of(rq) against smp_processor_id() in
          cfs_rq_util_change().

---
 drivers/cpufreq/Kconfig            |    5 --
 drivers/cpufreq/cpufreq_governor.c |    2 -
 drivers/cpufreq/intel_pstate.c     |    2 -
 include/linux/sched.h              |   12 ++++--
 kernel/sched/cpufreq.c             |    2 -
 kernel/sched/cpufreq_schedutil.c   |   67 ++++++++++++++++++++-----------------
 kernel/sched/deadline.c            |    4 +-
 kernel/sched/fair.c                |   10 +----
 kernel/sched/rt.c                  |    4 +-
 kernel/sched/sched.h               |   31 +++++------------
 10 files changed, 66 insertions(+), 73 deletions(-)

(...)

quoted

--- linux-pm.orig/drivers/cpufreq/Kconfig
+++ linux-pm/drivers/cpufreq/Kconfig

@@ -194,7 +194,7 @@ config CPU_FREQ_GOV_CONSERVATIVE
          If in doubt, say N.

 config CPU_FREQ_GOV_SCHEDUTIL
-       tristate "'schedutil' cpufreq policy governor"
+       bool "'schedutil' cpufreq policy governor"

If you change such symbols please remember to update also all the
defconfigs. Without the update they start to show errors.

Are there defconfigs that use this particular one?

Yes, ARM/multi_v7 and exynos were using this as module. Javier sent a
patch for that and should be switched to builtin in upcoming next [1].

If you would like to base on top of that, let me know, so I would
prepare a tag.

I wouldn't like to rebase, but I can pull that branch depending on how
much more material there is on it.

Not much, I put only the fix m->y on a separate branch. Anyway if you
need it, here it is:


The following changes since commit 29b4817d4018df78086157ea3a55c1d9424a7cfc:

  Linux 4.8-rc1 (2016-08-07 18:18:00 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux.git tags/samsung-defconfig-schedutil-4.9

for you to fetch changes up to 08023fb9cec03ee2992df51fa728c3f14a1ba0ea:

  ARM: multi_v7_defconfig: Don't attempt to enable schedutil governor as module (2016-08-19 17:50:13 +0200)

----------------------------------------------------------------
The schedutil cpufreq governor will be switched from tristate to bool. Fix
defconfigs.

----------------------------------------------------------------
Javier Martinez Canillas (2):
      ARM: exynos_defconfig: Don't attempt to enable schedutil governor as module
      ARM: multi_v7_defconfig: Don't attempt to enable schedutil governor as module

 arch/arm/configs/exynos_defconfig   | 2 +-
 arch/arm/configs/multi_v7_defconfig | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)