// ITS FOSS — LINUX & OPEN SOURCE
Linux 7.3 is Shaping Up to Be One of The Most Performance-Focused Kernel Releases in Years
We posted on X a few days back, calling Linux 7.3 one of the most performance-focused releases in years. And now, going through what has actually landed in the merge window since then, that claim does seem to hold up.
The merge window for this release opened right after Linux 7.2 arrived, staying open until the end of this month barring any last-minute happenings that move the closure.
So, here's what is confirmed to go into the 7.3 release so far.
Btrfs picks up several changes at once. Direct I/O now runs through an IOmap bounce buffer instead of falling back to buffered I/O, taking a workflow that topped out around half of the theoretical maximum throughput up to close to 95 percent of it.
Two separate fixes in the logging and fsync paths add roughly 5x gains each, one from removing an unnecessary delay when multiple logging tasks run at once, the other from skipping unneeded hole detection during full fsync on files with lots of extents but no holes.
The default free-space cache also moves from v1 to v2, the safer and faster option that had not yet become the default.
EXT4 gets its own round of work too. Parallel direct I/O writes are now allowed where the filesystem used to be too restrictive, and the multi-block allocator skips unnecessary work through fallocate().
Underneath both filesystems sits a reworked IOmap layer built around a single iterator callback the compiler can inline instead of dispatching indirectly.
You don't need to do anything for any of this. It just works once you're on 7.3, and the IOmap change pays off the most on fast NVMe, pushing EXT4 from 1.92 million IOPS to 2.19 million in testing.
Peter Zijlstra's flatten-the-pick patches rework cgroup scheduling around a single runqueue instead of the old, hitch-prone design. Peter tested it on an aging Sandy Bridge box paired with an AMD Radeon RX 580, and both frame rate and frame-time consistency improved.