Re: [patch 01/27] fs: cleanup files_lock

[ebiederm@xmission.com (Eric W. Biederman)]

npiggin@suse.de writes:

> Lock tty_files with tty_mutex, provide helpers to manipulate the per-sb
> files list, and unexport the files_lock spinlock.

This conflicts a bit with some of my ongoing work, which is generalizing
the file list to make it more useful and makes the tty case much less
of a special case.

Do you know if the performance improvement would be anywhere near as good if
file_list and file_list_lock becoming per inode?

Do you have any idea what the performance improvement with changing the file_list_lock
is?


> Index: linux-2.6/fs/open.c
> ===================================================================
> --- linux-2.6.orig/fs/open.c
> +++ linux-2.6/fs/open.c
> @@ -828,7 +828,7 @@ static struct file *__dentry_open(struct
>  	f->f_path.mnt = mnt;
>  	f->f_pos = 0;
>  	f->f_op = fops_get(inode->i_fop);
> -	file_move(f, &inode->i_sb->s_files);
> +	file_sb_list_add(f, inode->i_sb);

You can make this just:
	 if (!special_file(inode->i_mode))
		file_add(f, &inode->i_files);

And save yourself a lot of complexity.

Eric