Re: [gentoo-user] Jobs and load-average

[Peter Humphrey]

On Wednesday, 15 February 2023 13:18:24 GMT Rich Freeman wrote:
> On Wed, Feb 15, 2023 at 4:56 AM Peter Humphrey <peter@××××××××××××.uk>
wrote:
> > Not long ago I read that we should allow 2GB RAM for every emerge job -
> > that is, we should divide our RAM size by 2 to get the maximum number of
> > simultaneous jobs. I'm trying to get that right, but I'm not there yet.
> >
> > I have these entries in make.conf:
> > EMERGE_DEFAULT_OPTS="--jobs=16 --load-average=32 --autounmask=n --quiet-
> > unmerge-warn --ke>
> > MAKEOPTS="-j16"
> >
> > Today, though, I saw load averages going up to 72. Can anyone suggest
> > better values to suit my 24 threads and 64GB RAM?
>
> First, keep in mind that --jobs=16 + -j16 can result in up to 256
> (16*16) tasks running at once.  Of course, that is worst case and most
> of the time you'll have way less than that.
>
> Keep in mind that you need to consider available RAM and not just
> total RAM.  Run free under the conditions where you typically run
> emerge and see how much available memory it displays.  Depending on
> what you have running it could be much lower than 64GB.
>
> Beyond that, unfortunately this is hard to deal with beyond just
> figuring out what needs more RAM and making exceptions in package.env.
>
> Also, RAM pressure could also come from the build directory if it is
> on tmpfs, which of course many of us use.
>
> Some packages that I build with either a greatly reduced -j setting or
> a non-tmpfs build directory are:
> sys-cluster/ceph
> dev-python/scipy
> dev-python/pandas
> app-office/calligra
> net-libs/nodejs
> dev-qt/qtwebengine
> dev-qt/qtwebkit
> dev-lang/spidermonkey
> www-client/chromium
> app-office/libreoffice
> sys-devel/llvm
> dev-lang/rust   (I use the rust binary these days as this has gotten
> really out of hand)
> x11-libs/gtk+
>
> These are just packages I've had issues with at some point, and it is
> possible that some of these packages no longer use as much memory
> today.

Thank you all. I can see what I'm doing better now. (Politicians aren't the 
only ones who can be ambiguous!)

I'll start by picking up the point I'd missed - putting MAKEOPTS in 
package.env.

-- 
Regards,
Peter.