Re: [patch] smarter atime updates

From: Hans Reiser (reiser@namesys.com)
Date: Sat Dec 01 2001 - 04:22:22 EST


Marcelo Tosatti wrote:

>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.
>>
>>-
>>
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at http://vger.kernel.org/majordomo-info.html
>Please read the FAQ at http://www.tux.org/lkml/
>
>
nice optimization.

Hans

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Fri Dec 07 2001 - 21:00:15 EST