[PATCH] reduce sizeof(struct file)

Now that RCU applied on 'struct file' seems stable, we can place f_rcuhead
in a memory location that is not anymore used at call_rcu(&f->f_rcuhead,
file_free_rcu) time, to reduce the size of this critical kernel object.

The trick I used is to move f_rcuhead and f_list in an union called f_u

The callers are changed so that f_rcuhead becomes f_u.fu_rcuhead and f_list
becomes f_u.f_list

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 8a8c34461d48..b638fb500743 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -533,7 +533,7 @@ static void proc_kill_inodes(struct proc_dir_entry *de)
          */
         file_list_lock();
         list_for_each(p, &sb->s_files) {
-                struct file * filp = list_entry(p, struct file, f_list);
+                struct file * filp = list_entry(p, struct file, f_u.fu_list);
                 struct dentry * dentry = filp->f_dentry;
                 struct inode * inode;
                 struct file_operations *fops;