On Thu, Feb 08, 2007 at 12:43:28PM -0800, David Miller wrote: > From: Heiko Carstens <[EMAIL PROTECTED]> > Date: Thu, 8 Feb 2007 21:32:10 +0100 > > > So either all spin_lock_bh's should be converted to spin_lock, > > which would limit smp_call_function()/smp_call_function_single() > > to process context & irqs enabled. > > Or the spin_lock's could be converted to spin_lock_bh which would > > make it possible to call these two functions even if in softirq > > context. AFAICS this should be safe. > [...] > In short, it's a mess :-) > > I think it's logically simpler if we disallow smp_call_function*() > from any kind of asynchronous context. But I'm sure your driver > has a true need for this for some reason.
I just want to avoid that s390 has different semantics for smp_call_functiom*() than any other architecture. But then again it will probably not hurt since we allow more. Another thing that comes into my mind is smp_call_function together with cpu hotplug. Who is responsible that preemption and with that cpu hotplug is disabled? Is it the caller or smp_call_function itself? If it's smp_call_function then s390 would be broken, since then we would have int cpus = num_online_cpus()-1; in preemptible context... I agree: what a mess :) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
