Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [Ksummit-2010-discuss] [v2] Remaining BKL users, what to do | Date | Tue, 19 Oct 2010 09:26:54 +0200 |
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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.
Arnd
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