vfs: only read fops once in fops_get/put
In do_dentry_open() the usage is:
f->f_op = fops_get(inode->i_fop);
In generated asm the compiler emits 2 reads from inode->i_fop instead of
just one.
This popped up due to false-sharing where loads from that offset end up
bouncing a cacheline during parallel open. While this is going to be fixed,
the spurious load does not need to be there.
This makes do_dentry_open() go down from 1177 to 1154 bytes.
fops_put() is patched to maintain some consistency.
No functional changes.
Reviewed-by: Josef Bacik <[email protected]>
Signed-off-by: Mateusz Guzik <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>
1 file changed
