Re: [Ksummit-2010-discuss] [v2] Remaining BKL users, what to do

On Wed, Oct 20, 2010 at 06:50:58AM +1000, Dave Airlie wrote:

On Tue, Oct 19, 2010 at 11:26 PM, Arnd Bergmann [off-list ref] wrote:

quoted

On Tuesday 19 October 2010, Arnd Bergmann wrote:

quoted

On Tuesday 19 October 2010 06:52:32 Dave Airlie wrote:

quoted

quoted

I might be able to find some hardware still lying around here that uses an
i810. Not sure unless I go hunting it. But I get the impression that if
the kernel is a single-CPU kernel there is not any problem anyway? Don't
distros offer a non-smp kernel as an installation option in case the user
needs it? So in reality how big a problem is this?

Not anymore, which is my old point of making a fuss. Nowadays in the
modern distro world, we supply a single kernel that can at runtime
decide if its running on SMP or UP and rewrite the text section
appropriately with locks etc. Its like magic, and something like
marking drivers as BROKEN_ON_SMP at compile time is really wrong when
what you want now is a runtime warning if someone tries to hotplug a
CPU with a known iffy driver loaded or if someone tries to load the
driver when we are already in SMP mode.

We could make the driver run-time non-SMP by adding

      if (num_present_cpus() > 1) {
              pr_err("i810 no longer supports SMP\n");
              return -EINVAL;
      }

to the init function. That would cover the vast majority of the
users of i810 hardware, I guess.

Some research showed that Intel never support i810/i815 SMP setups,
but there was indeed one company (http://www.acorpusa.com at the time,
now owned by a domain squatter) that made i815E based dual Pentium-III
boards like this one: http://cgi.ebay.com/280319795096

Also that board has no on-board GPU enabled i815EP (P means no on-board GPU).

A quick search seems to indicate that an i815E variant also existed.

-- 
Ville Syrjälä
syrjala@sci.fi
http://www.sci.fi/~syrjala/
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html