Linux 6.0-rc1 Released With Exciting Performance Optimizations, New Hardware Support

After the two week long merge window, Linus Torvalds this afternoon released the first release candidate of Linux 6.0. Over the next roughly two months the Linux 6.0 kernel will stabilize but already from my early testing on various systems it is in nice shape and the features and performance are looking great.

Linux 6.0 is looking very good on the performance front with seeing great uplift on high-end Intel Xeon and AMD EPYC servers as well as AMD Threadripper while I'll have more desktop/laptop tests from Linux 6.0 over the weeks ahead. There has been some very nice and significant performance improvements.

Linus Torvalds codenamed Linux 6.0-rc1 the "Hurr durr I'ma ninja sloth" kernel.

I'll have up my lengthy Linux 6.0 feature overview tomorrow, but here is a quick overview. Linux 6.0 brings continued driver additions for Intel Raptor Lake, new RISC-V extensions, support for setting the system hostname via the "hostname=" kernel parameter, AMD Automatic Mode Transition for Lenovo ThinkPad laptops, Intel Habana Labs Gaudi2 support, the HEVC/H.265 interface has been promoted to stable, the new AMD Raphael audio driver, some early work on Intel Meteor Lake support such as with audio, perf tooling for AMD Zen 4 IBS, Intel IPI virtualization for KVM, AMD x2AVIC for KVM, Intel SGX2 support, run-time verification for safety critical systems, Send Protocol v2 for Btrfs, big scheduler enhancements, more AMD Zen 4 preparations, continued AMD RDNA3 graphics enablement, and some very nice IO_uring improvements. That's the quick overview but overall Linux 6.0 is a very exciting kernel!

Linux 6.0 is a big boy with having the greatest number of files changes and new lines added in quite a while... More than one million lines of code were added this cycle, in part due to auto-generated header files around new AMDGPU and Intel Habana Labs Gaudi2 support. In comparison the Linux 5.19 merge window saw 789k lines of new code. Linux 6.0 is going to be big.

For as exciting as Linux 6.0 changes are, there are a few features not merged this weekend... The Rust for Linux patches haven't yet been merged... Hopefully next cycle. The performance-enhancing MGLRU work also didn't make it this cycle nor the Maple Tree work, but the hope is both of those features should be ready for Linux 6.1. The Linux real-time "PREEMPT_RT" patches are also very close to the finish line but weren't sent in either for v6.0.

Linus Torvalds is also aware of some recently brought up Linux kernel crashes that appear to be attributed to the VirtIO merge and is already being worked through. Hopefully that will all be in good shape for Linux 6.0-rc2 next weekend.

Linus wrote in the Linux 6.0-rc1 announcement:

I actually was hoping that we'd get some of the first rust infrastructure, and the multi-gen LRU VM, but neither of them happened this time around. There's always more releases. But there's a lot of continued development pretty much all over the place, with the "shortlog" being much too long to post and thus - as always for rc1 notices - below only contains my "merge log". You can definitely get a kind of high-level overview by just scanning that, but obviously it's worth once again pointing out that the people mentioned in the merge log are just the maintainers I pull from, and there's more than 1700 developers involved when you start looking at the full details in the git tree.

Stay tuned for my Linux 6.0 feature write-up tomorrow and plenty of Linux 6.0 kernel benchmarks to come on Phoronix over the coming weeks. Linux 6.0 stable should be out around the end of September or early October.

Update - 15 Aug: The Linux 6.0 feature overview is now published.