maemo.org - Talk - Hibernation / Supsend to Disk

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- - Hibernation / Supsend to Disk (https://talk.maemo.org/showthread.php?t=33682)

Re: Hibernation / Supsend to Disk

Quote:

Originally Posted by nashith (Post 361383)

This would be a very interesting feature, not seldom used a lot, but there are several circumstances I wish I could just remove the battery/change SIM without going through a full reboot. Could be a nice feature to be implemented by the community. Any coders around for it?

http://talk.maemo.org/showthread.php?t=32167

e: and here's straight answer:

Quote:

Originally Posted by allnameswereout (Post 337938)

Hibernation and most suggestions on lesswats.org aren't or are barely interesting on ARM and other mobile/embedded devices. You'd need to write all the data in RAM to swap, and read all that again when powering it up. That uses a lot time, and also resources/juice, while the ARM in idle mode barely uses juice. You might as well leave no application open instead, put all receivers and transmitters off, or only leave voice open for phone/SMS, or suspend an application which uses a lot of resources. When battery almost empty Symbian has option to disable cellular data. Alternatively, something like powertop or iotop or htop could help debug (in SDK or on real device). All these 3 run on Linux/ARM.

http://talk.maemo.org/showpost.php?p...8&postcount=25

Re: Hibernation / Supsend to Disk

Quote:

Originally Posted by www.rzr.online.fr (Post 361226)

Talking about that, is powertop available for ARM ?

Yes, the N900 comes with it.

Re: Hibernation / Supsend to Disk

Trying to make the discussion of power consumed during reboot experimental, rather than theortical or mythological, I ran my N810 through reboot loops. Here are the results:

No route to host is when the N810 did not boot after it powered off for some reason.

The results of the experiment are that the battery managed 44 reboot cycles. If we take the official 240 hours standby time, it means that a reboot cycle is equivalent to about 5.5 hours of standby.

Code:

14:11:10:~$ for i in `seq 1 100` ; do echo $i ; ssh n810 battery-status ; ssh n810 battery-status ; ssh n810 reboot ; sleep 150 ; done

1

[Oct 30 14:13] 99.6%

[Oct 30 14:13] 99.6%

2

[Oct 30 14:15] 99.6%

[Oct 30 14:15] 99.6%

3

[Oct 30 14:24] 99.6%

[Oct 30 14:24] 99.6%

4

[Oct 30 14:27] 99.6%

[Oct 30 14:27] 99.6%

5

[Oct 30 14:32] 99.2%

[Oct 30 14:32] 99.2%

6

[Oct 30 14:35] 99.6%

[Oct 30 14:35] 99.6%

7

[Oct 30 14:37] 99.6%

[Oct 30 14:37] 99.6%

8

[Oct 30 14:40] 99.6%

[Oct 30 14:40] 99.6%

9

[Oct 30 14:43] 99.6%

[Oct 30 14:43] 99.6%

10

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

11

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

12

[Oct 30 14:51] 99.2%

[Oct 30 14:51] 99.2%

13

[Oct 30 14:53] 99.6%

[Oct 30 14:53] 99.6%

14

[Oct 30 14:56] 99.6%

[Oct 30 14:56] 99.6%

15

[Oct 30 14:59] 99.6%

[Oct 30 14:59] 99.6%

16

[Oct 30 15:01] 99.6%

[Oct 30 15:01] 99.6%

17

[Oct 30 15:04] 99.6%

[Oct 30 15:04] 99.6%

18

[Oct 30 15:07] 99.6%

[Oct 30 15:07] 99.6%

19

[Oct 30 15:09] 99.6%

[Oct 30 15:09] 99.6%

20

[Oct 30 15:12] 55.2%

[Oct 30 15:12] 55.2%

21

[Oct 30 15:15] 50.0%

[Oct 30 15:15] 50.0%

22

[Oct 30 15:17] 52.4%

[Oct 30 15:17] 52.4%

23

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

24

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

25

[Oct 30 15:25] 99.6%

[Oct 30 15:26] 99.6%

26

[Oct 30 15:28] 47.6%

[Oct 30 15:28] 47.6%

27

[Oct 30 15:31] 45.6%

[Oct 30 15:31] 45.6%

28

[Oct 30 15:34] 39.6%

[Oct 30 15:34] 39.6%

29

[Oct 30 15:36] 35.2%

[Oct 30 15:36] 35.2%

30

[Oct 30 15:39] 32.4%

[Oct 30 15:39] 32.4%

31

[Oct 30 15:42] 38.4%

[Oct 30 15:42] 38.4%

32

[Oct 30 15:44] 28.4%

[Oct 30 15:44] 28.4%

33

[Oct 30 15:47] 27.2%

[Oct 30 15:47] 27.2%

34

[Oct 30 15:50] 23.6%

[Oct 30 15:50] 23.6%

35

[Oct 30 15:52] 28.4%

[Oct 30 15:52] 28.4%

36

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

37

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

38

[Oct 30 16:00] 32.0%

[Oct 30 16:00] 32.0%

39

[Oct 30 16:03] 26.4%

[Oct 30 16:03] 26.4%

Terminated

40

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

ssh: connect to host 192.168.15.229 port 22: No route to host

41

[Oct 30 16:09] 25.6%

[Oct 30 16:09] 25.6%

42

[Oct 30 16:11] 16.0%

[Oct 30 16:11] 16.0%

43

[Oct 30 16:14] 18.4%

[Oct 30 16:14] 18.4%

44

[Oct 30 16:17] 11.6%

[Oct 30 16:17] 11.6%

45

[Oct 30 16:19] 10.0%

[Oct 30 16:19] 10.0%

46

[Oct 30 16:22] 8.4%

[Oct 30 16:22] 8.4%

47

[Oct 30 16:25] 6.4%

[Oct 30 16:25] 6.4%

48

[Oct 30 16:27] 5.2%

[Oct 30 16:27] 5.2%

49

[Oct 30 16:30] 3.6%

[Oct 30 16:30] 3.6%

50

[Oct 30 16:33] 4.0%

[Oct 30 16:33] 4.0%

51

[Oct 30 16:35] 0.0%

[Oct 30 16:35] 0.0%

Re: Hibernation / Supsend to Disk

Heh, someone actually coming up with data to back up the discussion! :D
Thanks for that, very interesting. And it seems to back up the assertion that a reboot sucks about as much as the night's sleep anyway. 44 reboots, that's probably a reasonably fresh battery. The battery I finally replaced (from Jan. 2007) could only manage a couple of reboots when fully loaded, and barely a single reboot after a day.

Re: Hibernation / Supsend to Disk

Actually, it is an almost two years old and heavily used battery. I actually estimate that it now holds about 50% as much power as a new battery.

If you look at the battery reading, you will note that it reads the battery as full for about 15 reboots, then goes from full to 55% in one reboot, and goes approximately linearly to 0% from there.

Re: Hibernation / Supsend to Disk

Quote:

Originally Posted by Matan (Post 361664)

Actually, it is an almost two years old and heavily used battery. I actually estimate that it now holds about 50% as much power as a new battery.

What do you mean by "If we take the official 240 hours standby time,"? is that for a new battery or for idle mode with your old battery?

Re: Hibernation / Supsend to Disk

Thanks for the experimentation. Regarding:

Quote:

The results of the experiment are that the battery managed 44 reboot cycles. If we take the official 240 hours standby time, it means that a reboot cycle is equivalent to about 5.5 hours of standby.

It would be useful if you could calculate how much standby time you get on that particular battery. (I realise that means you can't use the tablet for a few days!) That way you can do a more accurate calculation on how many "standby hours" a reboot is equivalent of.

Re: Hibernation / Supsend to Disk

My N800 battery didn't start to show its age until it was about 26-27 months old. Up until this I had no indication of detoriation. After this point though it became noticably worse at a rate which was visible in some 2-months steps, until it fiinally became almost unusable around now (34 months old).

Re: Hibernation / Supsend to Disk

Quote:

Originally Posted by ossipena (Post 361386)

http://talk.maemo.org/showpost.php?p...8&postcount=25
Originally Posted by allnameswereout:
Hibernation and most suggestions on lesswats.org aren't or are barely interesting on ARM and other mobile/embedded devices. You'd need to write all the data in RAM to swap, and read all that again when powering it up. That uses a lot time, and also resources/juice, while the ARM in idle mode barely uses juice. You might as well leave no application open instead,

hibernation is very interesting if your goal is to preserve the state of all applications during intentional (long period) or forced (battery low) power off.

I also doubt that a hibernate cycle consumes as much power as a full shutdown/boot cycle. Experiments with a Linux notebook could shed some light on that issue...

Re: Hibernation / Suspend to Disk

There are some patches for suspend to disk for ARM/OMAP,
however, for older kernel versions:
http://elinux.org/Suspend_To_Disk_For_ARM

they claim that the snapshot boot would dramatically reduces booting time