Re: [gentoo-user] Re: webrsync {SOLVED}

[Dale]

Rich Freeman wrote:
> On Sat, Feb 29, 2020 at 4:33 AM Wols Lists <antlists@××××××××××××.uk> wrote:
>> I just have a massive swap space, and /var/tmp/portage is a tmpfs. So
>> everything gets a fast tmpfs build, and it spills into swap as required
>> (hopefully almost never).
>>
> I can articulate a bunch of reasons that on paper say that this is the
> best approach.
>
> In practice I've found that swap on linux is sub-optimal at best.  I
> only enable swap when I absolutely have to as a result.  I'll reduce
> -j to lower memory demand before adding swap usually.  On more
> RAM-constrained hosts I'll enable swap when building specific
> packages, or try to avoid those packages entirely.
>
> Maybe something has changed in the last few years and swap is actually
> useful, but I'm skeptical.  I always tend to end up with GB of free
> RAM and a churning hard drive when I enable it.  On SSD I'm sure it
> will perform better, but then I'm running through erase cycles
> instead.
>
> Like I said, on paper adding swap should only make things better.
> But, that is only true if the kernel makes the correct choices about
> prioritizing swap vs cache use.  Sure, I could set swappiness to zero
> or whatever, but then that just turns swap into a NOOP best case and
> it isn't like I have OOM issues, so why bother?.
>


I have a large swap space on my rig.  Like you tho, I hate when it is
used because it renders my system almost unresponsive.  Even switching
from one desktop to another can take a minute or even longer.  I think
swappiness is set to 20 or some low number.  I only use it because while
slow, I can usually kill the offending process before things start
crashing.  I just start htop, highlight the offending process and kill
it.  Usually it is a web browser or something that doesn't get hurt to
much from being killed.

While swap can be a necessary evil, I hate when even 1MB is used. 
Runaway processes is one reason I expanded my memory to 32GBs. It gives
me more wiggle room for portage to be on tmpfs.

You are not alone in your experience with this. 

Dale

:-)  :-)