Re: [patch] smarter atime updates

Marcelo Tosatti
2001-11-30T17:02:08Z

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.
>
> -
>