Linux Plumbers in Prague: what the sched_ext microconference discussed

The Linux Plumbers Conference blog has published a report from the sched_ext microconference held in Prague. LWN.net linked to it on October 28. sched_ext lets Linux kernel task schedulers be implemented as BPF programs. According to the report, the discussions centered on three topics.

Priority inversion

The first topic was priority inversion and how to handle it in sched_ext. Participants discussed preemption of tasks that hold a lock or are waiting for one, as well as time slice extension. A separate question was how to make proxy execution work together with BPF schedulers.

Paravirtualized scheduling

The second topic concerned virtual machines. The goal is to let the host and guest schedulers cooperate across the VM boundary. In this arrangement, sched_ext serves as the policy engine on the host.

Device and topology awareness

The third topic was device- and topology-aware scheduling. Discussion covered using hardware feedback (Intel HFI), proximity to devices and accelerators, and cache topology to decide where tasks should run.

Overall, the agenda shows sched_ext developers increasingly tackling problems that reach beyond a single core or a single machine, from cooperating with the hypervisor to acting on hints from the processor itself.

Source: LWN.net