RE: [gentoo-user] Controlling emerges

[Laurence Perkins <lperkins@openeye.net>]

> -----Original Message-----
> From: Wol <antlists@youngman.org.uk> 
> Sent: Wednesday, September 20, 2023 3:07 PM
> To: gentoo-user@lists.gentoo.org
> Subject: Re: [gentoo-user] Controlling emerges
> 
> > What you have is not a portage problem. It is a orthodox parallelism 
> > problem, and I think you are thinking your constraint is unique in the 
> > work - it isn't.
> > With parallelism, trying to fiddle single nodes to improve things 
> > overall never really works out.
> > 
> A big problem you are missing is that portage does not have control of the system. It can control its usage of the system, but if I want emerge to use as much SPARE resource IN THE BACKGROUND as it can without impacting on on-line responsiveness, that is HARD.
> 
> I would like to be able to tell portage "these programs are resource hogs, don't parallelise them". If portage has loads of little jobs, it can fire them off one after the other as resource becomes available. If it fires a hog (or worse, two) off at the same time, the system can rapidly collapse under load.
> 
> Even better, if portage knew roughly how much resource each job required, it could (within constraints) start with the jobs that required least resource and run loads of them, and by firing jobs off in order of increasing demandingness, the number of jobs running in parallel would naturally tail off.
> 
> At the end of the day, if the computer takes an extra 20% time, I'm not bothered. If I'm sat at the computer 20% time extra because the system isn't responding because emerge has bogged it down, then I do care. And when I'm building things like webkit-gtk, llvm, LO, FF and TB, they do hammer my system. If they're running in parallel, my system would be near unusable.
> 
> Cheers,
> Wol

Maybe take a look at "cpulimit" out of the repos.  I used to use it on one of my low-power systems to control how much load the various compilers were allowed to put on the system so that it could keep doing other tasks.

I think there are some other, similar tools as well.

LMP