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").
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
include/linux/fs.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7eb4f706d59f..6c19f87ea615 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -998,9 +998,9 @@ 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.
@@ -1011,9 +1011,9 @@ 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;
--
2.43.0
--dkh3nrolmgchewwv--
