Re: [PATCH V3] x86, UV: BAU performance and error recovery

[Greg KH <gregkh@suse.de>]

On Fri, May 28, 2010 at 06:36:23PM -0500, Cliff Wickman wrote:
> /proc/sgi_uv/bau_tunables would be a read/write file to display and change
> nine threshold and delay values for tuning the BAU driver.
> 
> I like debugfs, except that a distro may not build the kernel with it
> configured on.  The tunables should be available as administrative
> options on a customer kernel, not just as a development tool.

All distros have debugfs turned on now, and mounted, due to the perf
interface there, as well as a lot of other good debug information that
is present.

So you don't have to worry about that.

> And in our case the distros are already building with other such writable
> options in /proc/sgi_uv.  We'd like to postpone a wholesale move of such
> options (assuming there will be some better place) and stay with the existing
> location for this release.

So because some distro took a non-upstream patch, you want upstream to
accept the patch despite it being the incorrect place to put such a
file?  Heh, you might want to rethink that...

> I know we (the community) would like to move non-process info out of /proc.

Yes.  We also don't want new files added there that are not dealing with
processes.

> It seems to me that we need a similar filesystem for large and/or 
> administrative files.  That's my perspective.

I do not know of any other such "large administrative" file that needs
to be added to the system at such a time, becides this one, do you?

So please, just put it in debugfs.

thanks,

greg k-h