On Tue, Jun 30, 2020 at 6:30 PM Kevin Kofler <kevin.kofler(a)chello.at> wrote:
Ben Cotton wrote:
>
https://fedoraproject.org/wiki/Changes/KDEEarlyOOM
>
> == Summary ==
> As [[Changes/EnableEarlyoom|Fedora Workstation did in F32]], install
> earlyoom package, and enable it by default. If both RAM and swap go below
> 10% free, earlyoom issues SIGTERM to the process with the largest
> oom_score. If both RAM and swap go below 5% free, earlyoom issues SIGKILL
> to the process with the largest oom_score. The idea is to recover from out
> of memory situations sooner, rather than the typical complete system hang
> in which the user has no other choice but to force power off.
I am opposed to this change, for the same reasons I was opposed to EarlyOOM
to begin with: this solution kills processes under arbitrary conditions that
are neither necessary nor sufficient to prevent a swap thrashing collapse
(i.e., it can both kill processes unnecessarily (false positives) and fail
to kill processes when it would be necessary to prevent swap thrashing
(false negatives)). It is also unclear that it can prevent full OOM (both
RAM and swap completely full) in all cases, due to EarlyOOM being a
userspace process that races with the memory-consuming processes and that
may end up not getting scheduled due to the very impending OOM condition
that it is trying to prevent.
I strongly believe that this kernel problem can only be solved within the
kernel, by a synchronous (hence race-free) hook on all allocations.
I still believe that too, except *nobody cares in the Linux kernel
community*. This problem has existed for a decade, and nobody in the
Linux kernel community is interested in fixing it. At this point, I've
given up. Most of us have given up. If they ever get around to doing
the right thing, I'll happily punt all this stuff, but they won't, so
here we are.
You can believe it until you're blue in the face, it doesn't matter if
they don't care. Unless you are going to fix it? :)
> == Owner ==
> * Name: [[User:bcotton|Ben Cotton]]
> * Email: bcotton(a)redhat.com
Why is this not owned by Rex Dieter and/or some other KDE SIG member?
If you want, I'll happily attach my name to it if that's what it takes
to feel "blessed". I'm a KDE SIG member as well.
--
真実はいつも一つ!/ Always, there's only one truth!