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

From: Shaohui Zheng
Date: Tue May 18 2010 - 04:05:22 EST


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

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