Re: [PATCH v3] PM / wakeup: show wakeup sources stats in sysfs

[Tri Vo]

On Mon, Jul 15, 2019 at 1:37 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Mon, Jul 15, 2019 at 01:11:16PM -0700, Tri Vo wrote:
> > Userspace can use wakeup_sources debugfs node to plot history of suspend
> > blocking wakeup sources over device's boot cycle. This information can
> > then be used (1) for power-specific bug reporting and (2) towards
> > attributing battery consumption to specific processes over a period of
> > time.
> >
> > However, debugfs doesn't have stable ABI. For this reason, create a
> > 'struct device' to expose wakeup sources statistics in sysfs under
> > /sys/class/wakeup/<name>/.
> >
> > Introduce CONFIG_PM_SLEEP_STATS that enables/disables showing wakeup
> > source statistics in sysfs.
> >
> > Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Tri Vo <trong@xxxxxxxxxxx>
> > Tested-by: Tri Vo <trong@xxxxxxxxxxx>
>
> Co-Developed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> perhaps given that I rewrote the whole file last time?  :)

Thanks again for the help!
>
>
> > ---
> >  Documentation/ABI/testing/sysfs-power |  73 ++++++++++++-
> >  drivers/base/power/Makefile           |   1 +
> >  drivers/base/power/wakeup.c           |  12 ++-
> >  drivers/base/power/wakeup_stats.c     | 148 ++++++++++++++++++++++++++
> >  include/linux/pm_wakeup.h             |  19 ++++
> >  kernel/power/Kconfig                  |  10 ++
> >  kernel/power/wakelock.c               |  10 ++
> >  7 files changed, 270 insertions(+), 3 deletions(-)
> >  create mode 100644 drivers/base/power/wakeup_stats.c
>
> What changed from v2?  :)

Oops, my bad.

> And I am guessing that you actually tested this all out, and it works
> for you?

Yes, I played around with wakelocks to make sure that wakeup source
stats are added/updated/removed as expected.

> Have you changed Android userspace to use the new api with no
> problems?

Kalesh helped me test this patch (added him in Tested-by: field in
latest patch version). We haven't tested beyond booting and manual
inspection on android devices. Android userspace changes should be
fairly trivial though.