Re: [RFC, 6/7] NUMA hotplug emulator

[Shaohui Zheng <shaohui.zheng@intel.com>]

On Tue, May 18, 2010 at 12:27:05AM -0700, Dave Hansen wrote:
> On Tue, 2010-05-18 at 13:41 +0800, Shaohui Zheng wrote:
> > On Thu, May 13, 2010 at 11:49:38AM -0700, Dave Hansen wrote:
> > the configfs was introduced in 2005, you can refer to http://lwn.net/Articles/148973/.
> > 
> > I enabled the configfs, and I see that the configfs is not so popular as we expected,
> > I mount configfs to /sys/kernel/config, I get an empty directory. It means that nobody is 
> > using this file system, it is an interesting thing, is it means that configfs is deprecated?
> > If so, it might not be nessarry to develop a configfs interface for hotplug.
> 
> Uh, deprecated?  What would make you think that?  It does look like the
> users are a we bit obscure, but that's a bit far from deprecated.
> 
> > Dave & Greg,
> > 	Can you provide an exmample to use configfs as interface in Linux kernel, I want to get
> > a live demo, thanks.
> 
> Heh.  There are some great tools out there called cscope and grep.  I
> have them on my system and I bet you can get them on yours too.
> 
> That said, you're right.  There don't seem to be a ton of users of it
> these days.  But, the LWN article you referenced also pointed to at
> least one user.  So, please try and put a wee bit of effort into it.

I am trying to put a few efforts on it, and we hope to support both sysfs and configfs.

because of the history reason, sysfs is more popular. I bet that only vew few users know
 configfs, so sysfs is still the prefered way.

> 
> Maybe configfs isn't the way to go.  I just think extending the 'probe'
> file is a bad idea, especially in the way your patch did it.  I'm open
> to other alternatives.  Since this is only for testing, perhaps debugfs
> applies better.  What other alternatives have you explored?  How about a
> Systemtap set to do it? :)
> 
> -- Dave

Did not try other alternatives until now. Thanks for Dave's suggestions, Systemtap and debugfs
 seems to be good methods, too.


-- 
Thanks & Regards,
Shaohui