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| author | Eric Dumazet <dada1@cosmosbay.com> | 2005-10-30 15:02:16 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-10-30 17:37:19 -0800 |
| commit | 2f51201662b28dbf8c15fb7eb972bc51c6cc3fa5 (patch) | |
| tree | 96826df796058560bc5dd1f7d8d476c5a741d7bc /fs/file_table.c | |
| parent | 503af334ecf23b9d65d2ff0cc759f3a0bf338290 (diff) | |
| download | lwn-2f51201662b28dbf8c15fb7eb972bc51c6cc3fa5.tar.gz lwn-2f51201662b28dbf8c15fb7eb972bc51c6cc3fa5.zip | |
[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>
Diffstat (limited to 'fs/file_table.c')
| -rw-r--r-- | fs/file_table.c | 14 |
1 files changed, 7 insertions, 7 deletions
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? */ |