Linux 4.18 required a somewhat uncommon eight release candidates and follows the Linux 4.17 release that was announced on June 3.
“One week late(r) and here we are – 4.18 is out there,” Linus Torvalds wrote in his release announcement. “It was a very calm week, and arguably I could just have released on schedule last week, but we did have some minor updates.”
Among the many capabilities added in the Linux 4.18 development cycle is one for energy-aware process scheduling, which is initially only supported on ARM.
“When cpufreq’s schedutil governor is selected, SCHED_DEADLINE implements the GRUB-PA  algorithm, reducing the CPU operating frequency to the minimum value that still allows to meet the deadlines,” the kernel pull message states.
Linux 4.18 also integrated a new asynchronous I/O interface that improves system polling performance.
“The changes were sponsored by Scylladb, and improve performance of the seastar framework up to 10 percent, while also removing the need for a privileged SCHED_FIFO epoll listener thread, kernel developers Christoph Hellwig wrote in a LKML thread.
ScyllaDB is a company that was co-founded by Avi Kivity, who is well known in the Linux kernel community for creating the Xen hypervisor. Scylla also created the seastar framework, which is a C++ framework used in the Scylla database.
Sean Michael Kerner is a senior editor at ServerWatch and InternetNews.com. Follow him on Twitter @TechJournalist.