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

From: Greg KH
Date: Fri May 28 2010 - 18:24:36 EST


On Fri, May 28, 2010 at 02:43:35PM -0500, Cliff Wickman wrote:
>
> On Fri, May 28, 2010 at 09:47:25AM -0700, Greg KH wrote:
> > On Fri, May 28, 2010 at 09:30:25AM -0700, H. Peter Anvin wrote:
> > > On 05/28/2010 06:33 AM, Cliff Wickman wrote:
> > > > - adds modification of tuning variables through /proc/sgi_uv
> > >
> > > Adding new directories in /proc for a proprietary architecture is
> > > frowned upon, to put it mildly. At the very least try to find a place
> > > in sysfs for it.
> > >
> > > [Cc: gregkh in order to find a place in sysfs]
> >
> > Hm, what type of files are you needing here? Do they corrispond with
> > any specific hardware devices? If so, just put them on the hardware
> > devices in sysfs.
> >
> > thanks,
> >
> > greg k-h
>
> There is an SGI-specific directory in sysfs: /sys/firmware/sgi_uv
> though the tuning variables for the handling of the hardware Broadcast
> Assist Unit don't fit there very logically.
>
> The BAU's statistics are already displayed through the UV-only
> /proc/sgi_uv/ptc_statistics. This was deemed necessary because of the
> potentially very large size of that file --- it is still true that a /sys file
> is limited to one page, is it not?

It is limited to one single value, which would never be larger than a
page, so yes, it is limited to one page.

What kind of information are you showing here? Should this thing just
be in debugfs instead? You can do whatever you want there.

thanks,

greg k-h
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