Restartable Sequences (rseq) are a kernel-based mechanism for fast update operations on per-core data in user-space. Some libraries, like the newest version of Google's TCMalloc, depend on it [1]. This also makes dockers default seccomp profile on par with systemd's, which enabled 'rseq' in early 2019 [2]. 1: https://google.github.io/tcmalloc/design.html 2: systemd/systemd@6fee3be Signed-off-by: Florian Schmaus <flo@geekplace.eu>