Re: [PATCH 2.4] add SMBIOS information to /proc/smbios -- UPDATED

Andi Kleen
2004-05-01T21:20:52Z

On Sat, May 01, 2004 at 04:00:44PM -0500, Lev Makhlis wrote:
> > > -- This information is, in the very near future, _not_ going to be
> > > static anymore. There will be systems that update the information in
> > > dynamically during SMIs.
> >
> > That's fine - /dev/mem can handle that too. An user will have to
> > poll for changes anyways, so having it it /proc does not have
> > any advantages.
>
> One problem is that /dev/mem access isn't atomic. You need to read
> a pointer, then follow the pointer to read data. If the pointer changes
> in the middle, you lose. That said, I don't see any mechanism that
> helps avoid that in kernel, either.
>

Exactly. The kernel code doesn't help with that.

You could always read everything twice and compare and do that until
it stops changing. I personally think it is overkill, because SMBIOS
information is normally only used for diagnosis, where a rare race
is not that bad.

Also hopefully the SMI handlers will change the thing in a atomic way,
so this may never happen.

-Andi