The Linux kernel is the backbone of Linux operating systems (OS), and is the fundamental interface between a computer's hardware and its processes.
The last Sunday, Linus Torvalds unveiled the launch of the new stable version of Linux kernel 6.5, version which introduces a lot of new features, new and updated drivers for better hardware compatibility, and other changes.
Of the most notable features of the Linux 6.5 Kernel, it is noted that support is introduced MIDI 2.0 in ALSA, ACPI support for the RISC-V architecture, and Landlock p supportfor UML (User-Mode Linux).
Linus Torvalds mentioned that he was a bit worried about this release.
“Nothing particularly weird or scary happened in the last week, so there is no excuse to delay the release of version 6.5. I still get the nagging feeling that a lot of people are on vacation and that things have been quiet partly because of that. But this launch went smoothly so it's probably just that I'm paranoid,” he wrote in a post on Sunday.
Main news in Linux 6.5
In this new released version of Linux 6.5, a of the most anticipated novelties and of which we had already spoken here on the blog, is the system cachestat(), whose purpose is to consult the status of the page cache for files and directories.
The new system call allows userspace programs to determine which pages of a file are cached in main memory. Unlike the previously available mincore() system call, the cachestat() call allows you to query more detailed statistics, such as the number of cached pages, dirty pages, evicted pages, recently evicted pages, and bookmarked pages. for rewrite.
Another of the changes that stands out in the Linux 6.5 kernel are the tools to run processors in parallel, which improves boot time on multisocket servers. This improvement is important for hyperscalers.
In addition to this, we can also find in Linux 6.5, support for USB 4.2, although it is worth mentioning that support is not yet complete. We can also find that Wi-Fi 7 has received more attention from the kernel, as well as the performance of the Btrfs file system that has been improved in this version
Linux 6.5 introduces hardware support for tabletss Lenovo Yoga Book yb1-x90f/ly Nextbook Ares 8A, Dell Studio 1569 (ACPI backlight issues), Lenovo ThinkPad X131e (AMD build 3371) and Apple iMac11,3 computers
On the other hand, it is highlighted that perhaps the most notable inclusion is the default P-state enable on some AMD processors, this means that the kernel can manage cores more efficiently to balance performance and power consumption.
P-State is enabled by default instead of the CPUFreq driver for power management. Added parameter X86_AMD_PSTATE_DEFAULT_MODE to select default P-State mode: 1 (disabled), 2 (passive power management mode), 3 (active mode, EPP), 4 (managed mode).
Of the other changes that stand out:
- Support for MIDI 2.0 devices has been added to the ALSA audio subsystem.
- The F2FS file system supports the “errors=” mount option, through which you can configure the behavior in case of errors when reading or writing data to the drive.
- Task scheduler has improved load balancing between CPU cores by eliminating unnecessary migration between SMT regions
- The SLAB memory allocation mechanism has been deprecated and will be removed in a future release, and instead only SLUB will be used in the kernel. Reasons cited are maintenance issues, code issues, and duplication of functionality with the more advanced SLUB allocator.
- Thanks to the parallel activation of several CPUs, the procedure for transferring processors to the online state has been significantly accelerated (up to 10 times).
- The Loongarch architecture supports Simultaneous Multithreading (SMT, Simultaneous Multithreading). It also provides the ability to build the Loongarch kernel with the Clang compiler.
- Added support for ACPI and the "V" extension ( Vector , vector instructions) for the RISC-V architecture. The parameter "/proc/sys/abi/riscv_v_default_allow" and the string of flags "PR_RISCV_V_*" are provided in prctl() to control the extension.
- On systems with ARM processors that support Armv8.8 extensions, the ability to use the memcpy/memset processor instructions in user space is provided.
Finally If you are interested in knowing more about it, you can check the details In the following link.