Morning! You may have solved this problem then

With screenshots, I usually mail them to myself and then upload from PC. But with the latest version of SystemDataScope you could generate report (Pulley menu, Report). When you call this function, all defined graphs are saved as PNG under /home/nemo/Documents/SystemDataScope/[DateTime]. You could see them under Gallery app with your photos. Select and send the ones that are needed and, after sending them, delete the folder /home/nemo/Documents/SystemDataScope. That would also clean up your Gallery from all the graphs. The main advantage of the report graphs is that they are made on white background and each file contains exactly one graph. If its easier to paste pictures on talk.maemo.org - please do so.

Coming back to your problem. It could be induced by the fact that your device is in deep sleep. In general, its a very good news and the small annoyance with the graphs should not disturb us from the fact that your device is behaving as intended.

If your explanation is right (which it probably is), you should see very long times under CPU details/CPU sleep details/Duration of a single suspend. Under long times I mean anything significantly longer than 150 seconds. If you are going to post the graphs, then please post also "CPU sleep" and "Duration of a single suspend".

The problem that you see could be a more general issue that is hard to solve at present. In general, data is acquired by collectd in several threads and written to RRDs. On PC, where CPU is always on, that works very well. On Sailfish, I have to wakeup the device using keepalive library, readout the data, and let the device go to sleep. I suspect that in you case, and it has happened on my phone as well, sometimes phone either does not wakeup (keepalive event is not fired?) or the phone manages to fall asleep faster than the data is recorded. Since there is inevitable variability in such wakeup/sleep cycle, I had to increase the allowed time-window for RRD writing which could lead to the effect that you see. Namely, old data gets interpolated over longer period of time.

If it is a problem with collectd not being able to record all the data during awake window, this may get fixed when upstream developers will help me with the port. I did submit the merge request in summer (https://github.com/collectd/collectd/pull/1736), but, due to the fact that its rather complex problem, I haven't had a chance to work on it with the developers who know how to tackle collectd multi-threaded internals

The interpolation is a problem for the values that are recorded as just "current values". Namely, you record a datapoint and hope that its an adequate representation of a variable during that time-window. Values in statefs are representing "current values" and, as a result, could fluctuate a bit too much. I presume that's why you see sometimes so high power consumption that is later interpolated over all deep sleep time window.

Fortunately, many values reported by the kernel are using additive approach. For example, kernel keeps counters on internet connections that are incremented. For these values, collectd takes derivative which would be a more accurate way to represent the network traffic irrespective on whether device was sleeping in between or not. These should be better represented in your case as well (CPU sleep, for example).

I hope that this explanation is helpful and, if your explanation is right, there are no problems with your device and you managed to hit either an issue with collectd data recording or that Sailfish just ignored keepalive request and does not wakeup in between. If it is collectd problem, we'll get a chance to work on it as a part of https://github.com/collectd/collectd/pull/1736.

cheers,

rinigus