On Thursday 25 February 2016 08:00 PM, Russell King - ARM Linux wrote: > On Thu, Feb 25, 2016 at 07:53:39PM +0530, Vineet Gupta wrote: >> But then ARM CONFIG_SMP on UP hardware will still crap out because there >> is no way to send IPI to self. Same as the bug in above discussion. I'm >> surprised they way ARM guys worked around it. > > We haven't worked around it - the code which provoked the oops that was > seen (in the cpufreq code) was changed not to call it, which has the > effect of making the problem "go away", at least for now. > > We still have the problem that if it does get called on UP, it'll blow > up - and I don't see any point in complicating the code for something > that never happens right now. Right so my statement "workaround" was technically incorrect. But like you say, it's a ticking bomb which will certainly go off on your SMP on UP systems the moment someone adds irq_work_queue_on() in some obscure corner of generic code. And I think this merits fixing in generic code ! -Vineet