It is perhaps unusual to have a kernel tracing developer leading a
filesystem session, Steven Rostedt said, at the beginning of such a session at the
2022 Linux Storage,
Filesystem, Memory-management and BPF Summit (LSFMM). But he was doing
so to
try to find a good way to dynamically allocate kernel data structures
for some of the pseudo-filesystems, such as sysfs, debugfs, and tracefs,
in the kernel.
Avoiding static allocations would save memory, especially on systems
that are not actually using any of the files in those filesystems.

Source: LWN.net – [$] Dynamically allocated pseudo-filesystems