diff options
| author | Christian Brauner <brauner@kernel.org> | 2024-08-22 16:14:46 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2024-08-28 13:06:12 +0200 |
| commit | a55d1cbd1720679cfe9837bce250e397ec513989 (patch) | |
| tree | d21d06bb5e34e8f3f761003eb59d1a9ebd0b387f /include/linux/fs.h | |
| parent | 1934b212615dc617ac84fc306333ab2b9fc3b04f (diff) | |
fs: switch f_iocb_flags and f_ra
Now that we shrank struct file by 24 bytes we still have a 4 byte hole.
If we move struct file_ra_state into the union and f_iocb_flags out of
the union we close that whole and bring down struct file to 192 bytes.
Which means struct file is 3 cachelines and we managed to shrink it by
40 bytes this cycle.
I've tried to audit all codepaths that use f_ra and none of them seem to
rely on it in file->f_op->release() and never have since commit
1da177e4c3f4 ("Linux-2.6.12-rc2").
Link: https://lore.kernel.org/r/20240823-luftdicht-berappen-d69a2166a0db@brauner
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'include/linux/fs.h')
| -rw-r--r-- | include/linux/fs.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 7af239ca87e2..095a956aeb29 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -999,9 +999,9 @@ struct file { struct callback_head f_task_work; /* fput() must use workqueue (most kernel threads). */ struct llist_node f_llist; - unsigned int f_iocb_flags; + /* Invalid after last fput(). */ + struct file_ra_state f_ra; }; - /* * Protects f_ep, f_flags. * Must not be taken from IRQ context. @@ -1012,9 +1012,9 @@ struct file { struct mutex f_pos_lock; loff_t f_pos; unsigned int f_flags; + unsigned int f_iocb_flags; struct fown_struct *f_owner; const struct cred *f_cred; - struct file_ra_state f_ra; struct path f_path; struct inode *f_inode; /* cached value */ const struct file_operations *f_op; |