Tracing a Memory Leak Bug In PID 1 And Contributing an Upstream Fix: a Linux Support Story
Ubuntu, Friday, July 17th, 2026
Canonical support traced a 70GB systemd memory leak at a global retailer to a kernel race condition and landed an upstream fix.
Canonical's support team was called in by a global retail organization whose systemd process (PID 1) was consuming roughly 70 GB of RAM instead of the expected 8 GB.
Investigation showed a misconfigured Ceph orchestration layer repeatedly attempting failed disk-zapping operations, producing continuous mount and unmount thrashing.
That thrashing triggered a kernel race condition which prevented glibc's allocator from returning freed memory to the operating system.
After isolating the fault through core dump analysis and reproducing it with a minimal test case, Canonical engineers worked with upstream kernel maintainers on a permanent fix that was merged into the mainline kernel and delivered to users through Ubuntu's Stable Release Update process.