This is the first issue I have ever opened to say that "your program works better than the alternative that you suggest"!
Test case, first without any optimizations:
backup-process takes 7 minutes (a mksquashfs chroot chroot.squashfs command)
While it's running, user-process takes 2.5 minutes (an ls -lR /home/username command)
Then I try with nocache:
nocache backup-process takes 9 minutes
While it's running, user-process takes 1.5 minutes
==> this is the correct optimization I'm looking for, to favor the user process.
Then I try the same thing with the systemd-run command that you mention in https://github.com/Feh/nocache#if-you-use-systemd.
I get the same results as "without any optimizations", 7 minutes and 2.5 minutes.
I do NOT notice this thing you mention:
During (notice how buff/cache only goes up by ~300MiB):
I was NOT able to make systemd-run limit the pagecache. buff/cache for me was using all the RAM, and my "free" column went down to almost zero.
Options for controlling the Legacy Control Group Hierarchy (Control Groups version 1 are now fully deprecated: CPUShares=weight, StartupCPUShares=weight, MemoryLimit=bytes, ...
So I tested with the recommended MemoryHigh instead, and I even tried MemoryMax, to no avail.
I was unable to make systemd-run NOT fill up the RAM with the pagecache, and as a result, the user-process couldn't keep its own pages in RAM and needed 2.5 minutes instead of 1.5 minute.
==> So I guess the actual issue is, "could you please update README.md with a working example for the newer cgroups v2?"
This is the first issue I have ever opened to say that "your program works better than the alternative that you suggest"!
Test case, first without any optimizations:
backup-processtakes 7 minutes (amksquashfs chroot chroot.squashfscommand)user-processtakes 2.5 minutes (anls -lR /home/usernamecommand)Then I try with nocache:
nocache backup-processtakes 9 minutesuser-processtakes 1.5 minutes==> this is the correct optimization I'm looking for, to favor the user process.
Then I try the same thing with the systemd-run command that you mention in https://github.com/Feh/nocache#if-you-use-systemd. I get the same results as "without any optimizations", 7 minutes and 2.5 minutes.
I do NOT notice this thing you mention:
I was NOT able to make systemd-run limit the pagecache. buff/cache for me was using all the RAM, and my "free" column went down to almost zero.
The systemd.resource-control manpage mentions that:
So I tested with the recommended MemoryHigh instead, and I even tried MemoryMax, to no avail. I was unable to make systemd-run NOT fill up the RAM with the pagecache, and as a result, the
user-processcouldn't keep its own pages in RAM and needed 2.5 minutes instead of 1.5 minute.==> So I guess the actual issue is, "could you please update README.md with a working example for the newer cgroups v2?"