Hi,
(ok, issue solved while writing the message - writing it anyway, for documentation).

I'm running GrapheneOs on Pixel 6a (most recent update, stable branch). After some initial tweaking when setting up gos ast summer), weeding out battery-eating apps, I've been quite happy with battery stats ever since.

Until ca. a week ago, when the battery started draining quite fast. Loosing 30-40% charge over night.
Tried restarting, and leaving only the "owner" profile active,- (which has very few apps installed) and not loggin into my personal profile, where all the apps are. Still the same.

using adb shell, and top, I got

  • system_server 21%
  • rild_exynos 12%
  • com.android.phone 10%
  • com.shannon.imsservice 10%
  • .ShannonImsService 6%
  • top 1.6%
  • servicemanager 1.6%

Now, somewhere on these forums, I found a hint that VoLTE might be causing this. So I turned it off. Now, top shows :

  • rild_exynos 6.6%
  • com.android.phone 2.0%
  • system-server 2.0%
    or less, basically normal, I would think.

So, just now, I called a friend, who works in the networks department at the telecom company, to ask him if they had changed something about the voLTE recently. They had not, but he knew that a lot of phones, (including pixels) had recently got a software update enabling voLTE.

Then he looked up my phone number, and found out, that voLTE was not enabled for it. He enabled voLTE for my number, I restarted the phone, and now the "top" results looks great (with voLTE enabled). No process eating more than 1%.

So he has seen similar behaviour - a number does not have VoLTE enabled, but the phone has it enabled in settings. Then, the phone goes into an endless loop asking for voLTE connection, getting rejected by the network, then asking for it again - this is probably what is causing this high cpu load (but now I'm guessing).

Greetings,
Indriði

Thanks for the info; this might be helpful for others in the future!

One clarification - the carrier generally has voLTE functionality, but does not have it enabled for all clients. They have been rolling it out in batches, and my phone number still did not have it, causing the network to reject the request for it.

Ok, one last comment on this.

My friend at the tel company looked up the package traffic for my phone last night. Phone was in owner-profile (few apps), my profile with all the apps logged out. VoLTE enabled on phone but disabled by network.

There was a "huge storm" (his words) of package traffic and requests by the phone to the network all night long. Seems to confirm the theory about endless-loop of reconnection logic in android.

He also said, that some carriers might handle this situation differently, and was going to look for ways for the carrier network to answer the voLTE requests differently so that the phone accepts that it does not have volte and stops trying.