On Tue, 30 Jan 2024 at 14:56, Linus Torvalds
[off-list ref] wrote:

With that, the base size of 'struct eventfs_inode' actually becomes 96
bytes for me.

It can be shrunk some more.

The field ordering is suboptimal. Pointers are 8 bytes and 8-byte
aligned, but 'struct kref' is just 4 bytes, and 'struct eventfs_attr'
is 12 bytes and 4-byte aligned.

So if you pack all the 8-byte-aligned fields at the beginning, and the
4-byte-aligned ones at the end, you get 88 bytes.

At which point a name pointer would *just* fit in 96 bytes.

...  and then some debug option is enabled, and it all goes to hell again.

              Linus