On Tue, Jan 28, 2025 at 7:51 PM Chris Murphy <li...@colorremedies.com> wrote: > > I'm a little confused about this new type of preemption. > > "The long road to lazy preemption" [1] article says: > > "The lazy mode will occupy a place between PREEMPT_NONE and > PREEMPT_VOLUNTARY, replacing both of them." > > Whereas Linux 6.13 change log [2] says: > > "lazy preemption" mode that aims to be a bridge between the voluntary and the > full preemption mode" > > I think Fedora would be interested in the latter, by default, for all Fedora > Linux variants. > > For some time, Fedora Workstation working group has been interested in > implementing full preemption, but there's been concern about enabling it > across the board among all Fedora variants. [3] > > So the first question is if lazy is somewhere between voluntary and full, and > if it is, how would we go about testing it in advance of making it the > default? > > > [1] > https://lwn.net/Articles/994322/) > > [2] > https://kernelnewbies.org/LinuxChanges#Linux_6.13.Lazy_preemption:_a_bit_more_of_preemption > > [3] > https://pagure.io/fedora-workstation/issue/228
It is being evaluated, but upstream is still a bit in the air as to where this is really going, and until they stabilize their direction, we can't really set ours either. FWIW, Clark was asking the internal performance team to evaluate the performance of LAZY vs VOLUNTARY and FULL so we should hopefully get real numbers on that sometime soon. I will re-evaluate the default for Fedora kernel builds based on the results of that testing and what upstream is doing. Of course we will still keep PREEMPT_DYNAMIC enabled, so people can select whatever they choose for their use case. Justin -- _______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org 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@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
