Re: [patch] smarter atime updates

[Marcelo Tosatti]

Now are you sure this can't break anything ? 

On Thu, 29 Nov 2001, Andrew Morton wrote:

> mark_inode_dirty() is quite expensive for journalling filesystems,
> and we're calling it a lot more than we need to.
> 
> --- linux-2.4.17-pre1/fs/inode.c	Mon Nov 26 11:52:07 2001
> +++ linux-akpm/fs/inode.c	Thu Nov 29 21:53:02 2001
> @@ -1187,6 +1187,8 @@ void __init inode_init(unsigned long mem
>   
>  void update_atime (struct inode *inode)
>  {
> +	if (inode->i_atime == CURRENT_TIME)
> +		return;
>  	if ( IS_NOATIME (inode) ) return;
>  	if ( IS_NODIRATIME (inode) && S_ISDIR (inode->i_mode) ) return;
>  	if ( IS_RDONLY (inode) ) return;
> 
> 
> with this patch, the time to read a 10 meg file with 10 million
> read()s falls from 38 seconds (ext3), 39 seconds (reiserfs) and
> 11.6 seconds (ext2) down to 10.5 seconds.
> 
> -
>