Disabling upowerd on a Desktop Linux computer that never actually had a battery.

One of the facts which I’d like to make sure the reader knows, is what, exactly, the process ‘upowerd’ is responsible for on any Linux computer, lest the reader disable something that he or she may really need.

Many computers, including laptops, have batteries. ‘upowerd’ is the Linux process that monitors the battery, or the batteries, in case there is more than one to monitor. If the computer has batteries to monitor, then this process is essential and should not be disabled. But, in certain specific other cases, this process can become a problem, as it recently was on my desktop computer named ‘Phosphene’, which is running Debian 9 / Stretch, which has Plasma 5.8 as its desktop manager, and which will only ever run on A/C power, due to the very way in which its hardware is designed.

Several months ago, I noticed that the ‘North Bridge’ of this computer – an essential chip on its motherboard – was becoming rather hot. And the motherboard in question, the ‘Sabertooth X58′, manufactured in the year 2011, was already famous for the design flaw that causes its North Bridge to become 76.5⁰C hot when idle, which is actually hotter than the GPU on that computer will normally become, when pressed to work hard. Several Months ago, the North Bridge temperature when idle was 80⁰C or even 81⁰C! Whether it’s actually safe for a chip to be that hot is a subject open to opinion. This temperature will not cause an immediate failure, but if the chip is so hot continuously, then its lifespan will become shorter, than what the lifespan of chips is supposed to be, in general.

Therefore, months ago, when I first noticed this, I opened up the tower / desktop computer and examined it, to look for failed cooling fans, etc. There was no such cause for the elevated NB temperature. Not being able to remedy the problem, I just left it that way.

But only yesterday, I noticed that the process ‘upowerd’ was consuming an inordinate amount of CPU time. On the octa-core machine, that process was consuming maybe 1% of available CPU time, which was quite a lot, considering that there should have been nothing for it to do. And, never having noticed this before, it seemed possible to me that ‘upowerd’ may have been consuming 1% of available CPU time (unnoticed), since months ago.

When ‘upowerd’ misbehaves in this way, sometimes this happens, because of hardware signals, such as perhaps, a battery which continuously disconnects and reconnects, etc… Therefore, before a software kludge is attempted, all possibilities need to be followed, to find hardware causes for this behaviour, to which ‘upowerd’ would simply be responding in a normal fashion. Yet, even given hardware reasons to be active, ‘upowerd’ should not be consuming much more than 1% of available CPU time, in case the reader has some situation where this process is consuming, say, 10% of the CPU.

Yesterday, just trying to resolve some sort of problem with the ‘upowerd’ daemon, I undertook to disable it, on the computer which will always be running on A/C, and which has no batteries to monitor

Fortunately, under Debian 9 / Stretch, this is an easy feature to disable. As root, the following two commands can be given:

 


# systemctl stop upower
# systemctl disable upower

 

The reader may be noticing, that the name of the service does not match that of the executable, which actually runs. However, stopping the service will cause its process to be killed, and, disabling the service will prevent the process from restarting after a reboot.

 

After I did this, not only did the annoying process no longer appear, but the North Bridge actually seems to be a few degrees cooler as well, on that computer! :-)  As I’m writing this, the NB temperature on that computer is 77.5⁰C, and no longer, 80⁰C or 81⁰C.

I don’t really know why, exactly, one phenomenon was affecting the other. What I do know is that the circuitry which is present, in the ICs of the Motherboard, is extremely complex, and could cause interactions which are sometimes unpredictable to the user. If the user really wanted to know, why or if this could happen to them, then such a user would actually need to speak to one of the specialists, who designed the chip, that acts as North Bridge, on a Sabertooth X58 motherboard.

But, I feel more comfortable now, in the belief that ‘Phosphene’ will continue to serve me well, for a few more years to come.


 

 

One possible reason why this problem may have been presenting itself on my own computer could have been related to the fact that, again several months ago, I installed a new power supply, and, at the hardware-level, that power supply may have been sending spurious signals, which would actually point to unstable power output. But, if that computer does have unstable power, then this has not led to any sort of malfunction that I can discern, in those same, recent months.

However, it may be the case that, every time there is some sort of supply voltage fluctuation, a Linux computer readies itself for an actual power failure. Doing so can cause unnecessary computations to be performed, and can actually increase the number of times the cache that computer has in RAM, is being synced to the actual hard-drive, since doing so is a reasonable precaution to take, if a power failure is being anticipated.

In short, having had this issue may also have caused the space on my hard drive to be slightly more fragmented then, than a Linux hard drive is supposed to be, due to an emergency sync being performed ?every second or two?

Yet, with this daemon disabled, the probability may now be higher, that an actual power failure could cause File System Corruption.

 

Dirk

 

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