[remux] battery drain

[raisjn]

from https://old.reddit.com/r/RemarkableTablet/comments/kwsp6h/remux_andor_koreader_drain_my_battery_fast/

I recently installed rm2fb, remux and koreader via toltec. This turns the remarkable2 into the perfect device for me: Having koReader's features (especially DAV and wallabag sync) completes the amazing note taking abilities for me.

But then I noticed how fast my battery gets drained. With remux active I lose 5-10% percent of my battery per hour, even if I have the wifi off and don't switch often between koReader and xochitl.

The battery usage is fine when I disable remux, but as soon as I restart it, the battery levels start to drop again. This battery life would make my remarkable less long lasting then a normal tablet, and thats just not an option...

Is this a known problem that I somehow missed? I didn't find any issues regarding power problems in any of the repos I looked at.

If not: Where should I start to troubleshoot? I don't see anything super suspicipus in log.txt or journalctl

I also have the ddvk-hacks installed, by they don't seem to affect the battery life as drastically, when remux is disabled.

[tobbsn]

Oh, thanks for reposting :D
I'm here too, btw ;)

[raisjn]

how do you test - through one hour of active usage?

and what version of remux? (should say in opkg info remux or similar command)

[Eeems]

Could this be related to rm2fb?

[tobbsn]

After unregularly checking the battery status for an afternoon, I started looking every ten minutes and the battery kept draining. I then tested by disabling remux and there was no recognizable battery decrease in the next half hour. But when I turned it back on, I lost several percent in the first half hour.

I did not actively disable rm2fb for that tests, tho. But I don't know if it would even be active without remux running.

reMarkable: ~/ opkg info remux
Package: remux
Version: 0.1.4-1
Status: install user installed
Section: launchers
Architecture: armv7-3.2
Maintainer: raisjn <of.raisjn@gmail.com>
Size: 179962
Filename: remux_0.1.4-1_armv7-3.2.ipk
Description: App launcher that supports multi-tasking applications
Installed-Time: 1610393897

[Eeems]

When remux is running (both foreground and background) what kind of CPU usage does it have?

[tobbsn]

top shows for remux

PID    PPID USER     STAT   VSZ %VSZ %CPU COMMAND
 5485     1 root     S    75004   7%   0% /opt/bin/remux   (in the background)
...
 5485     1 root     S    75012   7%   1% /opt/bin/remux   (active)

[raisjn]

after speaking to eeems, some next steps could be:

• collecting battery drain at regular intervals (30s - 1min)
• using pidstat to show the CPU usage of processes at regular intervals (30s - 1min)

then can collect usage logs and see what usage with and without remux looks like.

it will also help if anyone else can report in on battery usage and which rM version they are on

[raisjn]

updated comment from reddit:

it seems to have gotten a bit better with the last update to version 0.1.5-1, but I couldn't log a comparable time frame yet to verify that.

i think that i will try to add some logging mechanism for battery life that will let me analyze it later down the line, along with what apps were running.

[makbeta]

I am running remux on reMarkable (original) and noticed the battery drain as well. I installed the remux through opkg on my tablet. Part of the issue I found is that remux is still running even if I turn off the power via reMarkable UI. This may or may not be the cause of battery drain, but adding it here in case it is.

Reproduction steps:

• Turn on the tablet
• Load and use remux
• Turn the tablet's power off from the reMarkable UI or by holding the power button
• While the power is off, press and hold the middle button for 1 second, remux UI shows; this tells me that it's still running; my expectation is that this package stops running when the tablet is powered off
• If I hit Suspend button in the remux UI the tablet goes from power off to sleeping mode

[raisjn]

if this is on rm1, i believe there is two sleep states and in the first one, the front buttons will wake the tablet but xochitl ignores them.

your tablet might wake up if you press middle button (and not hold it) without remux, try plugging it into pc and you will get network connected event when middle button wakes it

[raisjn]

when i have time, i will give out scripts to log your battery life over time so you can see what is happening. it is simple to log a timestamp + current charge + whether it is charging and then look at it later.

with remux installed, i get 0.8% drain per hour during sleep on rm1

[raisjn]

rM1 Power Cases:

case 1 (xochitl sleep, front button wake):

• plug in USB (see "network detected")
• power down via xochitl (see "network disconnected")
• press front button (see "network connected")
• wait, see "network disconnected" after ~20s

case 2 (xochitl sleep, front button summon remux):

• plug in USB (see "network connected")
• power down via xochitl (see "network disconnected")
• hold front button (see "network connected" + remux UI)
• press "remarkable" (or click away from remux dialog)
• wait, see "network disconnected"

case 3 (sleep from remux):

• plug in USB (see "network connected")
• power down via remux (see "network disconnected")
• hold front button (see "network connected" + remux UI)
• tablet wakes up and shows xochitl UI
• press "remarkable" (or click away from remux dialog)
• tablet is now active

[makbeta]

@raisjn
Thanks for the detailed response.
I could not connect to SSH on the tablet once it's powered off and keypresses didn't wake it up. But I'm not looking at it with the same approach as you are. I think the power off details I noted are a tangent and perhaps unrelated.

The power down issue aside, I also noticed a big power drain once I started to use remux and keywriter. So I don't quite know which one causes power drain. I'm going to try another launcher and provide more details if I find that the battery drain is not as big with a different launcher.

[raisjn]

reMarkable: ~/ pidstat -u -C "(keywriter|remux)" -h 3
Linux 4.9.84-zero-gravitas (reMarkable)         02/20/21        _armv7l_        (1 CPU)

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:24:51        0      3938    0.00    0.98    0.00    0.00    0.98     0  remux

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:24:54        0      3938    0.33    2.33    0.00    0.00    2.67     0  remux

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:24:57        0      3938    1.00    0.33    0.00    0.00    1.33     0  remux
11:24:57        0      4728    7.33    1.67    0.00    0.00    9.00     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:00        0      3938    1.33    1.33    0.00    0.00    2.67     0  remux
11:25:00        0      4728   11.67    1.33    0.00    0.00   13.00     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:03        0      3938    0.33    2.67    0.00    0.00    3.00     0  remux
11:25:03        0      4728   13.33    1.67    0.00    0.00   15.00     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:06        0      3938    0.67    0.67    0.00    0.00    1.33     0  remux
11:25:06        0      4728    1.00    0.33    0.00    0.00    1.33     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:09        0      3938    4.67    2.33    0.00    0.00    7.00     0  remux
11:25:09        0      4728    5.00    0.67    0.00    0.00    5.67     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:12        0      3938    4.67    2.33    0.00    0.00    7.00     0  remux
11:25:12        0      4728    5.00    1.00    0.00    0.00    6.00     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:15        0      3938    4.33    2.33    0.00    0.00    6.67     0  remux
11:25:15        0      4728    5.00    0.67    0.00    0.00    5.67     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:18        0      3938    4.33    2.67    0.00    0.00    7.00     0  remux
11:25:18        0      4728    5.00    0.67    0.00    0.00    5.67     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:21        0      3938    4.33    2.33    0.00    0.00    6.67     0  remux
11:25:21        0      4728    4.67    1.00    0.00    0.00    5.67     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:24        0      3938    3.00    1.33    0.00    0.00    4.33     0  remux
11:25:24        0      4728    8.33    0.67    0.00    0.00    9.00     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:27        0      3938    0.33    3.67    0.00    0.00    4.00     0  remux
11:25:27        0      4728   12.00    5.00    0.00    0.00   17.00     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:30        0      3938    3.00    1.00    0.00    0.00    4.00     0  remux
11:25:30        0      4728   16.00    1.00    0.00    0.00   17.00     0  keywriter

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
11:25:33        0      3938    1.00    0.67    0.00    0.00    1.67     0  remux
11:25:33        0      4728    8.67    0.00    0.00    0.00    8.67     0  keywriter
^C

i installed keywriter and opened it, then did the following:

• move finger around - CPU is 2 - 4% for remux, 17% for keywriter
• move stylus: CPU is 6 - 7% for both remux and keywriter

i don't have a keyboard so i can't check what typing is like. but there's definitely room for remux to reduce CPU usage. (you can get pidstat with sysstat pkg in opkg)

EDIT: 0324d79 could help with stylus associated CPU usage

[raisjn]

reMarkable: ~/ pidstat -u -C "(keywriter|remux|xochitl|rm2fb)" -h 3
Linux 4.14.78 (reMarkable)      02/21/21        _armv7l_        (2 CPU)

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:08:38        0      3722    0.33    0.00    0.00    0.00    0.33     1  remux
00:08:38        0      3731    3.63    1.32    0.00    0.00    4.95     1  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:08:41        0      3722    0.67    0.00    0.00    0.00    0.67     1  remux
00:08:41        0      3731    5.00    1.00    0.00    0.00    6.00     1  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:08:44        0      3722    0.33    0.00    0.00    0.00    0.33     1  remux
00:08:44        0      3731    4.33    2.00    0.00    0.00    6.33     1  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:08:47        0      3722    0.33    0.33    0.00    0.00    0.67     1  remux
00:08:47        0      3731    5.00    1.00    0.00    0.00    6.00     1  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:08:50        0      3722    0.00    0.33    0.00    0.00    0.33     1  remux
00:08:50        0      3731    4.67    1.00    0.00    0.00    5.67     1  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:08:53        0      3731    0.33    0.67    0.00    0.00    1.00     1  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:08:56        0      3731   13.00    1.67    0.00    0.00   14.67     0  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:08:59        0      3731   21.67    5.00    0.00    0.00   26.67     1  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:09:02        0      3731   18.33    3.67    0.00    0.00   22.00     0  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:09:05        0      3722    0.00    0.33    0.00    0.00    0.33     1  remux
00:09:05        0      3731   37.13    5.21    0.00    0.00   42.35     0  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:09:08        0      3731   56.00    4.33    0.00    0.00   60.33     0  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:09:11        0      3731    8.33    2.67    0.00    0.00   11.00     0  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:09:14        0      3731    7.33    3.67    0.00    0.00   11.00     1  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:09:17        0      3731    6.67    4.00    0.00    0.00   10.67     1  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:09:20        0      3731    2.00    0.00    0.00    0.00    2.00     1  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:09:23        0      3722    0.33    0.00    0.00    0.00    0.33     0  remux
00:09:23        0      3731    6.00    0.67    0.00    0.00    6.67     0  xochitl

# Time        UID       PID    %usr %system  %guest   %wait    %CPU   CPU  Command
00:09:26        0      3722    0.33    0.33    0.00    0.00    0.67     0  remux
00:09:26        0      3731    5.33    1.00    0.00    0.00    6.33     0  xochitl
^C

on the rM2, i did:

• drag finger around: remux takes < 1% CPU, xochitl 6-7%
• move stylus around: remux at 0% with new changes (TODO: check old), xochitl at 11% (pencil) to 22% (drawing outside of a notebook)

i asked for help collecting pidstats samples (sysstat package) from others, so i hope to get more info on keywriter and other apps and how their CPU usage looks (not that CPU is the end all be all)