On 12/07/2020 09:04, William Kenworthy wrote:
Hi,
is there a way to change the MAKEOPTS setting on a running emerge?
I am using "-j 5 -l 4" whilst emerging gcc-9.3 but its creating too much
pressure on memory. I expect the emerge to take many more hours but
complete eventually - but reducing it to "-j2" will help other
operations whilst not losing whats already been completed (this is an
old atom N330 with 4G ram and is my gateway/router/firewall/snort/...
and the overload is starting to affect the network throughput
significantly).
No. But what you can do is lower its nice level to 19, and CPU and IO
priority to "idle". First, find the process IDs of emerge and make:
ps aux | grep emerge
ps aux | grep make
The first number after the user name (which is "root") is the pid. Then
do the following for both pids:
schedtool -D -n 19 pid
ionice -c 3 -p pid
ionice is in sys-apps/util-linux, so it's probably already installed.
schedtool though is in sys-process/schedtool and it might not be
installed. Nothing you can do about that right now. You have to wait it
out. ionice should help a bit though.
In the future, I *highly* recommend installing schedtool, and then put
this in your make.conf:
PORTAGE_NICENESS=19
PORTAGE_IONICE_COMMAND="sh -c \"schedtool -D \${PID}; ionice -c 3 -p
\${PID}\""
I have used this for many years now. It makes emerge have a virtually
imperceptible impact on my system. I can emerge for example gcc or
libreoffice with -j4 on my 4 cores/4 threads CPU, and I feel no slowdown
at all. This won't help with running out of RAM obviously, but it helps
immensely with keeping the system highly responsive.
Another thing I recommend is getting rid of "-j5". Use -j4. The "+1"
recommendation from decades ago does not apply anymore with modern Linux
kernels. You can test this yourself by emerging a smaller package that
takes like 2 minutes or so to emerge, and compare times with j4 and j5.
Most likely you will see no difference, other than j5 using more RAM.
