Task scheduling when device is locked and not charging

asked 2013-12-28 20:09:15 +0300

axaq gravatar image

updated 2014-01-10 21:23:58 +0300

lk gravatar image

I understand power consumtion reasons to change kernel scheduling if the device is locked (black screen).

I like to run simple shell commands or scripts via ssh connection also if the device is locked. But "sleep 1" could delay for a minute or longer in locked state. Also "vmstat 1" or "top" seem to hang.

Login with ssh could take more than 2 minutes! And you shouldn't scp files during locked state without charger connected. It would take ages ...

But if I'm pinging the device from outside every second it generates regular interrupts/events and the above commands don't hang.

How to avoid this power saving feature for shell commands. Any links or hints from MER or NEMO sites?

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Comments

Did you see in dmesg output any PM suspends ?

rsainio ( 2013-12-28 20:41:00 +0300 )edit

does this have the same effect if you play music and lock the device?

AL13N ( 2013-12-28 21:10:20 +0300 )edit

@rsainio: I do see "request_suspend_state: sleep (0->3) ..." when locked (black screen) and "request_suspend_state: wakeup (3->0) ..." when lockscreen is visible (backlight on).

axaq ( 2013-12-29 03:26:27 +0300 )edit

@AL13N: Playing music and locking the device doesn't show the hanging effect. It generates enough IO events like the ping. But dmesg shows the same request_suspend_state entries.

axaq ( 2013-12-29 03:29:07 +0300 )edit

Charging the device also doesn't show the hanging effect.

axaq ( 2013-12-29 03:34:22 +0300 )edit