[gentoo-user] Re: How to keep my system from (nearly) freezing?

[Kai Krakow]

Am Sun, 19 Feb 2017 14:11:29 +0100
schrieb Miroslav Rovis <miro.rovis@××××××××××××××.hr>:

> On 170219-13:53+0100, Helmut Jarausch wrote:
> > Hi,
> >
> > sometime I have some memory hungry ebuilds in the background, when
> > I
> Ebuilds are just text files, they don't run in the background...
>
> > start (e.g.) Chromium which needs very much memory if you have a
> > lot of open tabs.
> ( Chromium is the most privacy-invading browser ever. It's a spyware,
> I could never use it, but forget about that, it's not what this topic
> is about... )
> > In that case my system nearly freezes. I cannot even kill chrome.
> > What can I do in that case. (Remote login doesn't work either)
> Try Ctrl+Alt+Fx
> where x is one of F1 ... F6
> and then issue:
> # killa chromium
> >
> > Can I have any additional program (like Chromium) die if there is
> > not enough memory.
> >
> > Many thanks for a hint,
> > Helmut
> >
> This could be a hardware, not a software issue. Also, not sure, but
> looks like, not a memory issue, but a CPU issue.
>
> It's likely the CPU triggers the BIOS to shut down because CPU gets
> too hot, but because it is not properly implemented, what happens is
> even worse than doing nothing, and that is: the system freezes, but
> the CPU keeps running... Bad!
>
> How warm does you machine, try to touch it in the back, or under, if
> it's a laptop, where ther CPU is?
>
> It reminds me of what I had. My systems, that had only the original,
> run-of-the-mill coolers on the CPUs (I bought a few of same model MBO,
> so i can clone my systems)... The usual 80mm coolers.
>
> As soon as I replaced them with 120mm coolers, no issues any more.

I can second this. An optimized parallel emerge is able to keep your
cores fully busy at 100% almost all of the time. All components of the
cores are needed, so there's a lot of heat produced (artificial
benchmarks usually cannot do the same). You should see lines about
machine check exceptions (MCE) or CPU throttling logged into dmesg if
this hits you. CPU throttling is a real performance killer (ebuilds
suddenly take 10x the time) and may well explain what you are
seeing. Getting bigger fans and coolers can do magic here, even the
cheap ones.

I've only lately swapped the stock cooler for a Mars T1 and could now
set the turbo frequency limit back to 4.2 GHz without seeing these
messages during emerge (3.7 stock limit). Before, I had to turn off
turbo. I think the stock cooler was just aging (and dusted, couldn't
be removed, stuck like glue to the cooler).

So, check your cooler, blow the dust away, check the fan if it still
easily rotates when pushed with a finger while turned off. It helps a
lot. Maybe swap it with a better cooler/fan if you're experiencing
throttling (I recommend it).

-- 
Regards,
Kai

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