Linux 5.12 To Add Atomics Support To The Promising eBPF

The eBPF in-kernel virtual machine that allows for handling sandboxed "programs" within the Linux kernel continues on its stellar upward trajectory.

eBPF remains one of the most exciting and revolutionary changes in recent years within the Linux kernel and new features continue to be tacked on to allow eBPF to fulfill more roles than the original BPF network packet filter use-case. Should you not be too familiar with eBPF, learn more on the technology at eBPF.io.

What's new to report on today is support for atomics coming to eBPF. The atomics eBPF patches have been floating around for months but have now been queued into net-next, which means barring any last minute issues this code will end up in Linux 5.12.

This big addition adds support for atomic operations to the eBPF instruction set. The atomic operations were motivated for allowing globally-unique cookies in BPF programs but these atomic add / and / or / exchange / compare and exchange instructions can obviously be used for other purposes as well. The current atomics support doesn't extend the coverage to 8 or 16-bit operations nor does it add the notion of explicit memory barriers.

Those wanting to learn more about the atomics support for eBPF can see the patch message for all the details on this new capability.