:: Re: [DNG] Max Load Average
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Author: Bruce Perens
Date:  
To: Martin Steigerwald
CC: Devuan ML
Subject: Re: [DNG] Max Load Average
Newer Intel systems will indeed shut down during heavy use if you don't run
thermald. I don't know about AMD.

On Thu, Jul 18, 2024, 08:02 Martin Steigerwald <martin@???> wrote:

> Hi Simon, hi.
>
> Simon Hobson - 16.07.24, 22:06:18 CEST:
> > nisp1953 via Dng <dng@???> wrote:
> > > Another question here. What is the max load average I can run on my
> > > laptop? I am using Devuan 5.0 on a Lenovo T480S Thinkpad.
> >
> > Coming late to this …
> >
> > As others have said, there is no “correct” answer.
> >
> > I went for a look, and via StackExchange and ServerFault items came to
> > this blog
> > https://www.brendangregg.com/blog/2017-08-08/linux-load-averages.html
> > which I think is a really interesting discussion on what it means - and
> > it’s history.
>
> Which is exactly the one I mentioned and explained in my first response to
> this question. Did you read that?
>
> > But everything is a case of “relative to what is normal FOR YOU”. And
> > what is acceptable in terms of response times is also a matter of
> > “what’s OK for you” - e.g. adding a few seconds response delay on a
> > mail server probably won’t register, on an interactive terminal it will
> > drive the users mad.
>
> Important distinction.
>
> If its fast enough for you, it is fine. Simple as that.
>
> > As to what is safe, in general you should be able to load up a processor
> > fully and not suffer problems. Of course, if the design is ... a bit
> > marginal, then there may be issues. Or there may be a fault. I had a
> > laptop (Apple MacBook) some time ago which was dual-core (I think 8
> > threads) but couldn’t run two cores at high load without shutting down
> > for thermal protection. There was a known problem with that model where
> > there could be inadequate contact between processor and heatsink - the
> > cure being to take it apart, clean the faces, and reassemble with the
> > right thermal compound/pad. Apple actually did that for me at one of
> > their genius bars even though it was out of warranty :-) Before that,
> > if I was going to do a CPU intensive task, I’d use a utility that was
> > part of the developer tools to disable one core - running one core flat
> > out was safe, running two at a high load was guaranteed to cause a
> > shutdown which was “annoying”.
>
> I'd indeed suspect a hardware issue in case a thermal shutdown happens due
> to just loading the CPU. Actually with decent hardware I am sure you can
> just run stress -c 100 for days without any thermal shutdown. Should you?
> Again, no. Why put unnecessary load onto a machine? Unless you like to
> test whether the hardware delivers on any promises of the vendor. I'd
> basically return a ThinkPad it is cannot do stress -c 100 for a day
> without a thermal shutdown. But I do not even see a sense to test it. I am
> so certain that with any decently made laptop from any vendor it would not
> cause any issue that I do not even see a need to test it.
>
> If you however set the internal or discrete GPU to maximum MHz for long
> amount of times while having 28 degrees Celsius with lots of humidity in
> your room… you get what you ask for.
>
> > * I once admined a SCO OpenServer system where the application software
> […]
> > Of course, had this been Linux, we could have just stuffed a few G of
> > RAM in the system and it would have held the entire database in RAM !
>
> Interesting story.
>
> What I wonder is how out of memory conditions are / were handled by Unix
> based operating systems. That means once swap is exhausted as well.
>
> I still got not over the fact that in Linux the out of memory killer just
> forcefully terminates processes until it is fine again.
>
> A reliable operating should never *ever* forcefully kill a process without
> the user asking it to. But as long as some apps allocate virtual address
> space as if there was no tomorrow…
>
> Do you know anything about that?
>
> On the new ThinkPad T14 AMD Gen 5 there once was a reset of the internal
> GPU of the AMD Ryzen processor while I was playing Supertuxkart which
> really play with decent fps using all settings maxed out. This basically
> quit the game as well. Also not what I would consider to be reliable
> operating of processes.
>
> Ciao,
> --
> Martin
>
>
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