Linux Kernel 7.3 is Now Available

As anticipated, Linus Torvalds has officially launched the 7.3 kernel. The announcement was posted on October 18, 2026, by corbet.

Linus noted that since he managed to keep track of the calendar this week, the release wasn't randomly pushed back arrived right on schedule on Sunday afternoon. With 7.3 finalized, the merge window for version 7.4 is set to open tomorrow.

The "Submerge" Window

However, the transition to 7.4 will have a slight delay. Linus is currently on his yearly family getaway. Instead of diving into code first thing Monday morning, he will be spending his time on a boat and underwater.

Release Metrics

This version has shattered previous records across the board. The scale of contribution is illustrated in the table below:

To put the newcomer influx into perspective, we can look at the ratio of first-timers to total developers: $\text{Newcomer Ratio} = \frac{807}{3021} \approx 26.7\%$

Key Technical Enhancements

The 7.3 release introduces a wide array of updates, including:

• System Calls & Filesystems:
  • The introduction of the fchroot() system call.
  • A new filesystem called failfs (designed to fail every single operation).
  • Support for alternative data streams within the ntfs3 filesystem.
• Performance & Scheduling:
  • Improvements to group-scheduling to boost efficiency on massive systems.
  • The finalization of the sched_ext subscheduler functionality.
• Other Notable Additions:
  • Expanded capabilities for binfmt_misc.
  • Global per-CPU data implementation for BPF programs.
  • Working-set tracking specifically for virtual machines.
  • A comprehensive set of upgrades for the SMB server.

For those seeking deeper dives, refer to the KernelNewbies 7.3 page or the two-part LWN merge-window summaries.

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Community Discussion

📝 Developer Feedback

• jpeisach: Expressed excitement regarding the final development statistics.

📚 Learning Resources for Newcomers

A thread emerged regarding the best way to learn kernel development today:

1. swilmet noted that while The Linux Programming Interface is a staple for userspace interaction, its latest edition is from 2010. They also questioned if Linux Device Drivers is now too obsolete.
2. eru suggested starting with https://kernelnewbies.org/.
3. DragoonAethis pointed out that the "What's New" section of TLPI is unfortunately only being updated with version numbers now.
4. corbet recommended the official kernel development-process documentation, noting it is better maintained than other areas.

⚓ The "Submerge" Joke

The community found humor in Linus's vacation plans:

teknohog: "So before the Linux merge window, there's the Linus submerge window. (I'll get my coat!)"

zdzichu: "Quote of the week material."

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Post-Release Checklist

• Release Linux 7.3
• Finish scuba diving
• Open 7.4 merge window
• Return to normal sleep schedule

To check your current kernel version, you can use the following command in your terminal:

uname -r

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