lkml.org 
[lkml]   [2005]   [Jan]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRE: 2.6.10-mm3 scaling problem with inotify
From
Date
On Fri, 2005-01-14 at 10:31 +0800, Zou, Nanhai wrote:
>
> There is still a little difference between your implement in
> inotify_dentry_parent_queue_event from dnotify_parent
>
> In dnotify_parent, if parent is not watching the event, the code will
> not fall
> through dget and dput path.
>
> While in inotify_dentry_parent_queue_event kernel will go dget and dput
> even
> if (inode->inotify_data == NULL).
>
> While dget and dput will introduce a lot of atomic operations..
> And the most important, dput will grab global dcache_lock...,
> I think that is the reason why John Hawkes saw great performance drop.
>
> Simply follow dnotify_parent, only call dget and dput when
> inode->inotify_data != NULL will solve this problem I think.
>

Yeah, the old code was written before inode->inotify_data existed.
Robert caught this before he sent his patch. His patch should fix this
regression.

--
John McCutchan <ttb@tentacle.dhs.org>
-
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/

\
 
 \ /
  Last update: 2005-03-22 14:09    [W:0.049 / U:0.424 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site