Re: [PATCH 5/6] eventfs: get rid of dentry pointers without refcounts
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: 2024-01-30 23:06:32
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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