Re: [patch] fix netconsole hang with alt-sysrq-t

[Muli Ben-Yehuda]

On Thu, Aug 12, 2004 at 05:01:18PM -0400, Jeff Moyer wrote:

> So how do you want to deal with this case?  We could do something like:
> 
> 	int cpu = smp_processor_id();

That doesn't look right, unless I'm missing something, you could get
preempted here (between the smp_processor_id() and the
local_irq_save() and end up with 'cpu' pointing to the wrong CPU.

> 	local_irq_save(flags);
> 	if (!spin_trylock(&netpoll_poll_lock)) {
> 		/* allow recursive calls on this cpu */
> 		if (cpu != poll_owner)
> 			spin_lock(&netpoll_poll_lock);
> 	}
> 	poll_owner = cpu;

Cheers, 
Muli
-- 
Muli Ben-Yehuda
http://www.mulix.org | http://mulix.livejournal.com/

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