Extern or forward variable declaration at include/linux/smpboot.h, line 7 References: drivers/powercap/idle_inject.c, line 56 kernel/cpu.c, line 61 kernel/cpu.c, line 557 kernel/cpu.c, line 577 kernel/cpu.c, line 843 kernel/cpu.c, line 855 kernel/cpu.c, line 1204 kernel/rcu/tree.c, line 1182 kernel/rcu/tree.c, line 1520 kernel/rcu/tree.c, line 2810 kernel/rcu/tree.c, line 2822 kernel/rcu/tree.c, line 4361 kernel/smpboot.c, line 28 kernel/smpboot.c, line 30 kernel/smpboot.c, line 32 kernel/smpboot.c, line 53 kernel/smpboot.c, line 173 kernel/smpboot.c, line 231 kernel/smpboot.c, line 250 kernel/smpboot.c, line 273 kernel/softirq.c, line 59 kernel/softirq.c, line 75 kernel/softirq.c, line 89 kernel/stop_machine.c, line 38 kernel/stop_machine.c, line 52 kernel/stop_machine.c, line 537