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authorEric Dumazet <dada1@cosmosbay.com>2005-10-30 15:02:16 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2005-10-30 17:37:19 -0800
commit2f51201662b28dbf8c15fb7eb972bc51c6cc3fa5 (patch)
tree96826df796058560bc5dd1f7d8d476c5a741d7bc /fs/file_table.c
parent503af334ecf23b9d65d2ff0cc759f3a0bf338290 (diff)
downloadlwn-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.c14
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? */