Linux 7.4 workqueue patch yields 100x speedup on large servers

A workqueue flush optimization merged into the Linux 7.4 kernel delivers a 10 to 100-times speedup for asynchronous kernel operations on high-core-count servers. Written by kernel developer Tejun Heo to fix XFS log-forcing bottlenecks reported on 128-CPU systems, the patch modifies workqueue flushing so it only visits queues activated since the last flush rather than scanning every CPU core. On a 192-CPU test machine, idle per-CPU workqueue flushes jumped from 40,000 to 4.2 million operations per second without introducing regressions to active queue paths.

Phoronix · Oct 23, 2026