Yesterday, I have updated my Rawhide and wondered why `dnf autoremove` would want to remove earlyoom just to discover that soft dependency in earlyoom was dropped [1] and hence nothing requires earlyoom and DNF is free to remove this package (and it is possibly not installed anymore on upgraded systems). Therefore I wonder what is the status of EarlyOOM. Should I let the package go? If not, then the situation should be fixed somehow, probably either by reverting the revert or adding the dependency into fedora-release as was proposed elsewhere. Vít [1] https://src.fedoraproject.org/rpms/earlyoom/c/a6d0f45a3524830642a4120704e8d295598f8ec3?branch=master Dne 03. 01. 20 v 20:18 Ben Cotton napsal(a): > https://fedoraproject.org/wiki/Changes/EnableEarlyoom > > == Summary == > Install earlyoom package, and enable it by default. This will cause > the kernel oomkiller to trigger sooner, but will not affect which > process it chooses to kill off. 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. > > > == Owner == > * Name: [[User:chrismurphy| Chris Murphy]] > * Email: bugzilla@xxxxxxxxxxxxxxxxx > > == Detailed Description == > Workstation working group has discussed "better interactivity in > low-memory situations" for some months. In certain use cases, > typically compiling, if all RAM and swap are completely consumed, > system responsiveness becomes so abysmal that a reasonable user can > consider the system "lost", and resorts to forcing a power off. This > is objective a very bad UX. The broad discussion of this problem, and > some ideas for near term and long term solutions, is located here: > > Recent long discussions on "Better interactivity in low-memory situations"<br> > https://pagure.io/fedora-workstation/issue/98<br> > https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx/message/XUZLHJ5O32OX24LG44R7UZ2TMN6NY47N/<br> > > Fedora editions and spins, have the in-kernel OOM (out-of-memory) > manager enabled. The manager's concern is keeping the kernel itself > functioning. It has no concern about user space function or > interactivity. This proposed change attempts to improve the user > experience, in the short term, by triggering the in-kernel process > killing mechanism, sooner. Instead of the system becoming completely > unresponsive for tens of minutes, hours or days, the expectation is an > offending process (determined by oom_score, same as now) will be > killed off within seconds or a few minutes. This is an incremental > improvement in user experience, but admittedly still suboptimal. There > is additional work on-going to improve the user experience further. > > Workstation working group discussion specific to enabling earlyoom by default > https://pagure.io/fedora-workstation/issue/119 > > Other in-progress solutions:<br> > https://gitlab.freedesktop.org/hadess/low-memory-monitor<br> > > Background information on this complicated problem:<br> > https://www.kernel.org/doc/gorman/html/understand/understand016.html<br> > https://lwn.net/Articles/317814/<br> > > == Benefit to Fedora == > > There are two major benefits to Fedora: > > * improved user experience by more quickly regaining control over > one's system, rather than having to force power off in low-memory > situations where there's aggressive swapping. Once a system becomes > unresponsive, it's completely reasonable for the user to assume the > system is lost, but that includes high potential for data loss. > > * reducing forced poweroff as the main work around will increase data > collection, improving understanding of low memory situations and how > to handle them better > > > == Scope == > * Proposal owners: > a. Modify {{code|https://pagure.io/fedora-comps/blob/master/f/comps-f32.xml.in}} > to include earlyoom package for Workstation.<br> > b. Modify {{code|https://src.fedoraproject.org/rpms/fedora-release/blob/master/f/80-workstation.preset}} > to include: > <pre> > # enable earlyoom by default on workstation > enable earlyoom.service > </pre> > > * Other developers: > Restricted to Workstation edition, unless other editions/spins want to opt-in. > > * Release engineering: [https://pagure.io/releng/issues #9141] (a > check of an impact with Release Engineering is needed) <!-- REQUIRED > FOR SYSTEM WIDE CHANGES --> > > * Policies and guidelines: N/A > * Trademark approval: N/A > > == Upgrade/compatibility impact == > earlyoom.service will be enabled on upgrade. An upgraded system should > exhibit the same behaviors as a clean installed system. > > == How To Test == > * Fedora 30/31 users can test today, any edition or spin:<br> > {{code|sudo dnf install earlyoom}}<br> > {{code|sudo systemctl enable --now earlyoom}} > > And then attempt to cause an out of memory situation. Examples:<br> > {{code|tail /dev/zero}}<br> > {{code|https://lkml.org/lkml/2019/8/4/15}} > > * Fedora Workstation 32 (and Rawhide) users will see this service is > already enabled. It can be toggled with {{code|sudo systemctl > start/stop earlyoom}} where start means earlyoom is running, and stop > means earlyoom is not running. > > == User Experience == > The most egregious instances this change is trying to mitigate: > a. RAM is completely used > b. Swap is completely used > c. System becomes unresponsive to the user as swap thrashing has ensued > --> earlyoom disabled, the user often gives up and forces power off > (in my own testing this condition lasts >30 minutes with no kernel > triggered oom killer and no recovery) > --> earlyoom enabled, the system likely still becomes unresponsive but > oom killer is triggered in much less time (seconds or a few minutes, > in my testing, after less than 10% RAM and 10% swap is remaining) > > earlyoom starts sending SIGTERM once both memory and swap are below > their respective PERCENT setting, default 10%. It sends SIGKILL once > both are below their respective KILL_PERCENT setting, default 5%. > > The package includes configuration file /etc/default/earlyoom which > sets option {{code|-r 60}} causing a memory report to be entered into > the journal every minute. > > == Dependencies == > earlyoom package has no dependencies > > == Contingency Plan == > * Contingency mechanism: Owner will revert all changes > * Contingency deadline: Final freeze > * Blocks release? No > * Blocks product? No > > == Documentation == > {{code|man earlyoom}}<br><br> > https://www.kernel.org/doc/gorman/html/understand/understand016.html > > == Release Notes == > Earlyoom service is enabled by default, which will cause kernel > oom-killer to trigger sooner. To revert to previous behavior:<br> > {{code|sudo systemctl disable earlyoom.service}} > > And to customize see {{code|man earlyoom}}. > _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
