[gentoo-user] Load average revisited

[Peter Humphrey]

Afternoon all,

It seems that portage's self-protection from overload is incomplete - or so
I've been led to believe by some pretty odd goings-on.

Injudicious fiddling with -j, --jobs and --load-average can easily cause
miscompilation of packages without causing an OOM or any other sign of
problems.

For some time, I had those values set to take advantage of the 24 threads and
64GB of RAM in this machine (not to mention 8 + 50GB swap, little of which
appears ever to be used), resulting in the load average rising into three
digits at times - over 200, even. But no sign of difficulty was shown and all
appeared to have gone to plan. Until I ran the system, when odd errors would
show. One example I remember is Firefox having a bizarre colour scheme (the
window frame, not the page display) and missing the three upper-right buttons.
That wasn't corrected by recompiling Firefox, so I assume the problem was
lower down.

I think I have some safe values now (time will tell), but it's worrying that
compilation errors can go undetected. Of course I don't know where to start
looking for the problem; I just hope someone else does.

Meanwhile, is it possible to set things up so that, say, qtwebengine is never
compiled at the same time as anything else? I don't want to rely on my
noticing and intervening, and besides, it isn't always possible just to
--exclude it.

[Matt Connell]

Post by Peter Humphrey
One example I remember is Firefox having a bizarre colour scheme (the
window frame, not the page display) and missing the three upper-right buttons.
That wasn't corrected by recompiling Firefox, so I assume the problem was
lower down.

This feels strongly to me like something in your compositor, rather
than Firefox itself.

[Dr Rainer Woitok]

Peter,

Post by Peter Humphrey
...
Meanwhile, is it possible to set things up so that, say, qtwebengine is never
compiled at the same time as anything else? I don't want to rely on my
noticing and intervening, and besides, it isn't always possible just to
--exclude it.

What about

# emerge -1u qtwebengine && emerge -u @world

This will first update any dependencies of "qtwebengine" and only update
"qtwebengine" itself when all its dependencies are dealt with, before it
will deal with the rest.

Sincerely,
Rainer

[Matt Connell]

Post by Dr Rainer Woitok
What about
This will first update any dependencies of "qtwebengine" and only update
"qtwebengine" itself when all its dependencies are dealt with, before it
will deal with the rest.

What if qtwebengine's (many) dependencies also need to be updated
first? I think trying to outsmart the dependency graphing in portage
is inviting frustration.