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

Ville Syrjälä syrjala at sci.fi
Wed Oct 20 09:14:55 PDT 2010


On Wed, Oct 20, 2010 at 06:50:58AM +1000, Dave Airlie wrote:
> On Tue, Oct 19, 2010 at 11:26 PM, Arnd Bergmann <arnd at arndb.de> wrote:
> > On Tuesday 19 October 2010, Arnd Bergmann wrote:
> >> On Tuesday 19 October 2010 06:52:32 Dave Airlie wrote:
> >> > > 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 at sci.fi
http://www.sci.fi/~syrjala/


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