if (!nmi_callback(regs, cpu)) 
if (!rcu_dereference(nmi_callback)(regs, cpu)) 
asmlinkage void do_nmi(struct pt_regs * regs, long error_code){	int cpu = safe_smp_processor_id();	nmi_enter();	add_pda(__nmi_count,1);	if (!nmi_callback(regs, cpu))		default_do_nmi(regs);	nmi_exit();}
10457	/local/tlutelli/issta_data/temp/c/2005_temp/2005/10457/19306059cd7fedaf96b4b0260a9a8a45e513c857/nmi.c/clean/arch/x86_64/kernel/nmi.c