From 2f51201662b28dbf8c15fb7eb972bc51c6cc3fa5 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 30 Oct 2005 15:02:16 -0800 Subject: [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/file_table.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'fs/file_table.c') diff --git a/fs/file_table.c b/fs/file_table.c index 86ec8ae985b4..4dc205546547 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -56,13 +56,13 @@ void filp_dtor(void * objp, struct kmem_cache_s *cachep, unsigned long dflags) static inline void file_free_rcu(struct rcu_head *head) { - struct file *f = container_of(head, struct file, f_rcuhead); + struct file *f = container_of(head, struct file, f_u.fu_rcuhead); kmem_cache_free(filp_cachep, f); } static inline void file_free(struct file *f) { - call_rcu(&f->f_rcuhead, file_free_rcu); + call_rcu(&f->f_u.fu_rcuhead, file_free_rcu); } /* Find an unused file structure and return a pointer to it. @@ -95,7 +95,7 @@ struct file *get_empty_filp(void) f->f_gid = current->fsgid; rwlock_init(&f->f_owner.lock); /* f->f_version: 0 */ - INIT_LIST_HEAD(&f->f_list); + INIT_LIST_HEAD(&f->f_u.fu_list); return f; over: @@ -225,15 +225,15 @@ void file_move(struct file *file, struct list_head *list) if (!list) return; file_list_lock(); - list_move(&file->f_list, list); + list_move(&file->f_u.fu_list, list); file_list_unlock(); } void file_kill(struct file *file) { - if (!list_empty(&file->f_list)) { + if (!list_empty(&file->f_u.fu_list)) { file_list_lock(); - list_del_init(&file->f_list); + list_del_init(&file->f_u.fu_list); file_list_unlock(); } } @@ -245,7 +245,7 @@ int fs_may_remount_ro(struct super_block *sb) /* Check that no files are currently opened for writing. */ file_list_lock(); list_for_each(p, &sb->s_files) { - struct file *file = list_entry(p, struct file, f_list); + struct file *file = list_entry(p, struct file, f_u.fu_list); struct inode *inode = file->f_dentry->d_inode; /* File with pending delete? */ -- cgit v1.2.3