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/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
