14 DAY TRIAL // Today, March 14, 2016, Linus Torvalds and the hard-working team of kernel developers have been proud to announce the official release of Linux kernel 4.5, along with its immediate availability for download.
Yes, you're reading it right, after being in development for the past two months, Linux kernel 4.5 is now here in its final production version. Linux kernel 4.5 has received a total of seven RC (Release Candidate) builds since January 25, 2016, the last one having been announced by Linus Torvalds on March 6.
Prominent features of Linux kernel 4.5 include the implementation of initial support for the AMD PowerPlay power management technology, bringing high performance to the AMDGPU open-source driver for Radeon GPUs, scalability improvements in the free space handling of the Btrfs file system, and better epoll multithreaded scalability.
GCC (GNU Compiler Collection)'s UndefinedBehaviorSanitizer (UBSan) is now supported in Linux kernel 4.5 by using "-fsanitize=undefined," the memory controller now offers proper memory accounting of sockets, madvise() has received support for the MADV_FREE flag, and the cgroup unified hierarchy has reached stable.
"So this is later on a Sunday than my usual schedule, because I just couldn't make up my mind whether I should do another rc8 or not, and kept just waffling about it. In the end, I obviously decided not to, but it could have gone either way," says Linus Torvalds in today's announcement. "And on the whole, everything here is pretty small."
Linux 4.5 introduces copy offloading
Another important feature introduced in Linux kernel 4.5 is the addition of a copy_file_range system call that implements support for copying files without the need to transfer any data through userspace. The new feature is known as copy offloading. Linux kernel 4.5's internal codename is "Blurry Fish Butt."
Linux kernel 4.5 also adds scalability improvements to SO_REUSEPORT UDP sockets, and Forward Error Correction (FEC) support to the verity target of the device-mapper component. As usual, numerous drivers have been updated, and lots of bugs have been resolved. You can download Linux kernel 4.5 sources right now from kernel.org.