Sometimes intel_lpmd doesn't do anything

I'm making this bug report because I've noticed this some times already, but I've noticed that sometimes intel_lpmd is started but doesn't do anything, just reports that it sets wlt_idle and there's a lot of "received uevent" lines, but it never changes state. I just work around this by restarting it and then it works as normal

[Toxblh]

Hi @stereomato, looks like that is never works for me. Could you pls show how looks like log, when it works fine.

[spandruvada]

It is possible that from configuration, this is not enabled by default.

<BalancedDef>-1</BalancedDef>

But, you can do
intel_lpmd_control AUTO

even when that is set to 1, nothing happens. But I haven't tried current lpmd.

[jamlam]

I've been having similar issues with the current lpmd. There are some errors in the logs about being unable to write to a cgroup, it looks like if the device doesn't shut down cleanly these are left and prevent lpmd from functioning correctly. A restart resolves the issue by cleaning the old cgroup and creating a new one, this should be probably be handled automatically though. I can see there's been some work done on this already in an older release, does this need checking?

[spandruvada]

Can you try the latest version and see if you see issue.

[octomike]

I'm on main and see a similar behaviour - namely: nothing, unless I run intel_lpmd_control AUTO

Before, I see debug logs like this:

Dec 11 13:28:26 leslie intel_lpmd[272774]: wlt: 0
Dec 11 13:28:26 leslie intel_lpmd[272774]: [  Data] [    OFF] [DEFAULT_OFF]: WLT [ 0] CPUMASK [0003ffff] ITMT [1] EPB [6] EPP[power] Interval [-1]
Dec 11 13:28:27 leslie intel_lpmd[272774]: wlt: 1
Dec 11 13:28:27 leslie intel_lpmd[272774]: [  Data] [    OFF] [DEFAULT_OFF]: WLT [ 1] CPUMASK [0003ffff] ITMT [1] EPB [6] EPP[power] Interval [-1]
Dec 11 13:28:27 leslie intel_lpmd[272774]: wlt: 0
Dec 11 13:28:27 leslie intel_lpmd[272774]: [  Data] [    OFF] [DEFAULT_OFF]: WLT [ 0] CPUMASK [0003ffff] ITMT [1] EPB [6] EPP[power] Interval [-1]
Dec 11 13:28:28 leslie intel_lpmd[272774]: wlt: 3
Dec 11 13:28:28 leslie intel_lpmd[272774]: [  Data] [    OFF] [DEFAULT_OFF]: WLT [ 3] CPUMASK [0003ffff] ITMT [1] EPB [6] EPP[power] Interval [-1]
Dec 11 13:28:29 leslie intel_lpmd[272774]: wlt: 0
Dec 11 13:28:29 leslie intel_lpmd[272774]: [  Data] [    OFF] [DEFAULT_OFF]: WLT [ 0] CPUMASK [0003ffff] ITMT [1] EPB [6] EPP[power] Interval [-1]
Dec 11 13:28:29 leslie intel_lpmd[272774]: wlt: 3
Dec 11 13:28:29 leslie intel_lpmd[272774]: [  Data] [    OFF] [DEFAULT_OFF]: WLT [ 3] CPUMASK [0003ffff] ITMT [1] EPB [6] EPP[power] Interval [-1]

(using WLT hints only on M6 F170)

after setting to AUTO I get all the migration/enter/exit logs

[...]
Dec 11 13:29:28 leslie intel_lpmd[272774]: Ignore IRQ migration
Dec 11 13:29:28 leslie intel_lpmd[272774]: Ignore cgroup processing
Dec 11 13:29:28 leslie intel_lpmd[272774]: [ Enter] [   AUTO] [ WLT_BATTERY_LIFE ]: WLT [ 1] CPUMASK [16] IRQ [-1] ITMT [-1] EPB [6] EPP [178] SliderAC [-1] SliderDC [-1] OffsetAC [-1] OffsetDC [-1]
Dec 11 13:29:28 leslie intel_lpmd[272774]: [  Data] [   AUTO] [ WLT_BATTERY_LIFE ]: WLT [ 1] CPUMASK [0003ffff] ITMT [1] EPB [6] EPP[178] Interval [-1]
Dec 11 13:29:28 leslie intel_lpmd[272774]: wlt: 0
Dec 11 13:29:28 leslie intel_lpmd[272774]: [Choose] [   AUTO] [ WLT_IDLE ]: CPUMASK [16] IRQ [-1] ITMT [-1] EPB [15] EPP [255] SliderAC [-1] SliderDC [-1] OffsetAC [-1] OffsetDC [-1]

At first I thought I misunderstood the PerformanceDef/BalancedDef/PowersaverDef options. But no matter what value I put, I always end up with OFF/DEFAULT_OFF state.

[octomike]

For what it's worth, it also breaks the moment i switch from AUTO to ON and back to AUTO.

Debug output stays at:

Dec 11 13:55:47 leslie intel_lpmd[275383]: [  Data] [   AUTO] [ WLT_IDLE ]: WLT [ 0] CPUMASK [0003ffff] ITMT [0] EPB [15] EPP[power] Interval [-1]

and I don't see any WLT events / changes anymore. So I'm stuck on the efficiency cores. Going back to OFF and then AUTO makes it work again.